JP3124676B2 - Construction method of building foundation - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a building foundation and a construction method thereof, which can be used for the foundation construction of a building such as an industrialized house, and is particularly suitable for speeding up construction by using a precast concrete foundation block. It is.

[0002]

2. Description of the Related Art Conventionally, in a building such as a house, a foundation is constructed with a lower part buried in the ground, and pillars and the like serving as a basic structure are assembled thereon. In a prefabricated industrialized house, a panel, a box-shaped unit, and the like are assembled on a similar foundation, and a building securely fixed to the ground is constructed by these.

[0003] The foundation of such a building is generally formed by digging a groove in the ground, casting concrete on site, and filling the lower part after curing (RC foundation). On the other hand, in an industrialized house or the like, a precast concrete foundation block that has been factory-constructed in advance is arranged in a groove and joined to form a foundation (PC foundation). In such a PC foundation, since it is not necessary to wait for the concrete hardening time at the site, it is possible to reduce the site construction time.

[0004] Here, in any of the foundations, since a large load of the building is applied to the bottom of the groove where the foundation is installed,
In order to ensure the stability of the building, it is necessary to obtain sufficient load strength at the bottom of the trench (geological problem). In order to solve this problem, in the conventional foundation construction, for example, a procedure as shown in FIG.
No. 636861).

First, as shown in FIGS. 9 (A) and 9 (B), a construction machine 83 (so-called power source) equipped with a digging tool 82 (a narrow bucket or shovel) suitable for digging at the tip of a movable arm 81. A shovel or a backhoe) is carried into the construction site, and a groove 92 corresponding to the foundation is dug in the ground 91 of the site (root cutting process). The excavated earth and sand 93 is piled up in the vicinity.

Next, as shown in FIG. 9C, a trench 92 is filled with excavated soil 94, and a solidifying agent 95 such as a ground stabilizer and cement is added to the excavated soil 94. (Solidifying agent filling step).
Subsequently, as shown in FIG. 9D, the excavated soil 94 and the solidifying agent 95 are formed.
After sufficiently mixing and stirring the mixed soil 96,
Is temporarily rolled by the excavator 82 of the construction machine 83 (temporary rolling step).

After the preliminary rolling is completed, as shown in FIG.
The level between the mixed soil 96 and the current ground 91 is measured, and the operator corrects a location where the level difference is large or where there is uneven mixing (correction process). Next, as shown in FIGS. 9 (F) and 9 (G), the mixed soil 96 is subjected to main rolling by a rammer 86, a roller 87 and the like.

After completion of this compaction, the level is reconfirmed, and water is sprayed on the mixed soil 96 to adjust the water content. This spraying of water is not necessary if the solidifying agent 94 is mixed in an amount of 100 kg or more per square meter. After doing so, by taking a predetermined curing period, the ground improvement is completed.

[0009]

The above-mentioned foundation construction has an advantage that the ground can be improved only at the place where the foundation is arranged. However, since the rammer 86, the roller 87 and the like are used for the construction, the construction is not performed. There is a problem that it is troublesome. Further, in the above-described basic construction, it is necessary to manually adjust the excavated soil 96, and there is a problem that it is difficult to enhance the work efficiency (work efficiency problem).

On the other hand, as another method for solving the geological problem, there is a construction method of driving a pile deep into the ground to secure the strength of the foundation. However, a pile driving machine is required, which complicates construction and reduces construction costs. There is a problem that leads to a rise. Further, when the foundation 99 is cast in place, the excavator 83, the concrete pump truck, the crane truck, etc. must be replaced and approach the part where the foundation 99 is to be constructed. The operator and the rammer 86 need to enter and exit sequentially, and it is complicated to replace them, and the work efficiency is further reduced due to interruption of the work.

It is a main object of the present invention to provide a building foundation capable of constructing a foundation having sufficient strength even on poor ground such as soft ground and improving the working efficiency, and a construction method thereof. And, as another object, the present invention can improve the work efficiency in each step, can reduce the complexity of replacing the equipment,
Another object of the present invention is to provide a method for constructing a building foundation capable of improving the continuity of work.

[0012]

According to the present invention, as a result of intensive studies on foundation work and ground adjustment, it has been found that even soil of inferior geology can secure strength if it is solidified by mixing cement. It has been found that the soil that has been solidified with cement can secure the same strength as the conventional cracked stone, and that the solidification of soil and cement can be easily performed in the foundation work and that it can contribute to the efficiency of the process. This is based on knowledge.

[0013] Specifically, the building foundation in the present invention is:
A trench excavated and formed on the ground on which the building is constructed, a solidified layer formed with a predetermined thickness at the bottom of the groove, and a foundation constructed on the solidified layer, wherein the solidified layer is dug from the groove. It is composed of a material obtained by adding cement to the discharged earth and sand and solidifying, and a pair of opposed side wall surfaces of the groove are formed so as to be gradually inclined inward as going downward, and the side wall surface is It is characterized in that the solidified layer is in close contact. And the construction method of the building foundation of the present invention excavates the ground on which the building is constructed, and a groove corresponding to the foundation of the building, a pair of opposing side wall surfaces is gradually inclined inward as going downward. Forming cement, adding cement to the soil in the trench, flattening the cement, forming a solidified layer so as to be in close contact with the side wall surface, and constructing a foundation for the building on the solidified layer. Features.

The trench in the ground may be formed by using an existing excavating construction machine (such as the above-mentioned power shovel). At this time, it is desirable that the lower surface of the shovel can be used for compaction of earth and sand and cement, such as one having a relatively flat lower surface. The earth and sand generated by digging the groove is left in the groove to be solidified together with the cement, but may be partially removed according to the required amount.

When adding cement to the earth and sand, the cement may be sprayed on the earth and sand and then stirred with a shovel or the like, or the cement may be sprayed on the stirred earth and sand to penetrate the gaps between the earth and sand. May be. Furthermore, if the cement is sprayed after the pulverization of the earth and sand, and then the mixture is stirred, the finely divided earth and sand and the cement are sufficiently mixed, which is suitable for the subsequent solidification.

The mixing ratio of earth and sand to cement is appropriately adjusted according to the quality of the earth and sand (moisture content, sand content, particle size, etc.) so that a desired strength can be obtained upon solidification.

According to this structure, a solid layer formed by solidifying a mixture of earth and sand and cement is formed on the bottom surface of the groove in which the foundation is installed. Can be obtained. In addition, even when the soil excavated from the trench is soft mud, etc., stabilization by ground improvement can be achieved by adjusting the mixing ratio of cement, and a solidified layer can be formed firmly.

Since the solidified layer solidified at the bottom of the groove does not sink as in the case of cracked stone, a reliable foundation can be formed even on defective ground. In addition, complicated work such as laying of split rubble stones can be eliminated, and the earth and sand dug out of the trench is used for forming a solidified layer, so that wasteful disposal can be avoided. Therefore, such a configuration achieves the above-described main purpose of responding to soft ground and improving work efficiency.

Here, in forming the above-mentioned groove and solidified layer, first, a groove having a predetermined depth is dug in the ground, the earth and sand in the groove is taken out, and cement is sprinkled on the earth and sand, and the mixture is stirred and kneaded. The mixture of the kneaded cement and the earth and sand can be returned to the inside of the groove and crushed to form a solidified layer. By doing so, it is possible to perform easy kneading by existing work outside the groove, and to adjust the thickness and the like of the solidified layer formed in the groove according to the input amount of the cement soil mixture into the groove. Can also.

In addition, first, a trench having a predetermined depth is excavated in the ground, and cement is sprayed on the earth and sand excavated at the time of the excavation, and is stirred and kneaded simultaneously with the excavation. The solidified layer can be formed by squeezing the mixture of the cement and earth and sand. With this configuration, since the cement and the earth and sand can be mixed in the trench, the operation of carrying the earth and sand out of the trench can be omitted, and the operation can be simplified and the efficiency can be improved.

Furthermore, first, a groove having a predetermined depth is dug in the ground, and after removing the earth and sand in the groove, the cement is sprayed on the bottom surface. Then, the bottom surface on which the cement is sprayed is further excavated and stirred. The solidified layer can be formed by squeezing a mixture of cement and earth and sand generated in the groove. In this way, during the second excavation, the earth and sand are mixed with the cement at the same time, and the work efficiency in this process is improved, and the earth and sand from the second excavation solidify together with the cement, and The mixing amount of the earth and sand in the solidified layer can be easily and reliably adjusted depending on the depth, and also in this respect, the working efficiency can be improved.

Further, the method for constructing a building foundation according to the present invention comprises:
In spraying the cement, the bag filled with the cement is lifted, the lower end is cut open, the cement inside falls, and is put into the groove. With this configuration, it is possible to spray the cement bag having a considerable weight directly from the cement bag into the ditch, and it is possible to efficiently perform the process of spraying the cement on the soil in the ditch, thereby improving the working efficiency. Becomes possible.

In the case of carrying out moving spraying, it is desirable to appropriately adjust the size of the opening of the bag so as to adjust the spraying amount per time according to the moving speed.

Further, the method for constructing a building foundation according to the present invention is characterized in that the soil strength of the solidified layer is measured. In this way, after the above-described excavation, stirring and kneading, and tamping, by measuring the soil strength of the solidified layer, it is possible to confirm whether the solidified layer has sufficient strength, and thereafter In addition, it is possible to continuously carry out the work of constructing the foundation on the solidified layer, thereby making it possible to further improve the working efficiency.

The construction method of the building foundation according to the present invention comprises:
A precast concrete foundation block is used for the foundation, and a lower portion of the constructed foundation is filled with earth and sand or concrete. As the precast concrete foundation block, one having a cloth foundation-like cross section having a rising portion on a flat leg, or simply having a rising portion, a rectangular block forming an independent foundation, or the like can be used.

According to this structure, the foundation can be formed simply by arranging the preformed foundation blocks, and it is not necessary to cast the foundation in place. Therefore, it is possible to efficiently perform the steps after compacting the solidified layer. It becomes possible to improve the work efficiency as the whole foundation construction.

Further, the method for constructing a building foundation according to the present invention is characterized in that the step of excavating the trench, the step of adding cement, and the compacting step are performed using the same construction machine. As a construction machine that can execute each process, for example, the above-described power shovel or the like can be used.After excavating with a shovel, suspending a cement bag at the tip of the excavator and performing cement dispersion, and then performing shoveling of the shovel The mixture of earth and sand and cement may be beaten and squeezed on the lower surface.

At this time, the earth and sand and the cement may be agitated and mixed with a shovel between the application and the compaction of the cement. Alternatively, a roller-shaped or impeller-shaped stirrer may be installed on a vehicle body such as a power shovel, and stirring may be performed by this. With this configuration, it is possible to simplify or omit the replacement of construction machinery used in each step of the foundation work, and it is possible to eliminate the complexity of the conventional replacement and improve the work efficiency. Become.

Further, the method for constructing a building foundation according to the present invention comprises:
The step of excavating the groove, the step of adding the cement, the step of compacting, and the step of installing the precast concrete foundation block on the solidified layer are performed using the same construction machine. With this configuration, even in the process of installing the precast concrete foundation block on the solidified layer, it is possible to simplify or omit the replacement of the construction machine to be used, eliminating the complexity of the conventional replacement. And work efficiency can be improved.

Further, the method for constructing a building foundation according to the present invention comprises:
A mechanism for processing the respective steps is installed on the construction machine, and the construction machine travels along the ground on which the foundation of the building is to be installed, and the respective steps are continuously performed during the traveling. It is characterized by. As a mechanism for processing each step, an existing mechanism that can be used for each step may be used,
A mechanism used in another process may be used. For example, a mechanism for excavation such as the above-mentioned excavator, a mechanism for dispersing cement (using a dedicated hopper or a shovel, etc.), a mechanism for stirring earth and sand (using a dedicated agitator or a shovel, etc.), soil and cement It is only necessary to have a mechanism (such as a dedicated press device or diversion of the lower surface of the shovel) that performs tamping of the crawlers. Good.

Each mechanism can perform excavation or compaction by a single movement if it is arranged in the order of steps on a vehicle body or the like. However, the present invention is not limited to this order, and in such a case, the continuous processing may be performed by moving several times along the groove. With this configuration, each step of the foundation work can be continuously performed, and no waste time occurs between the steps, so that the work efficiency can be further improved.

Here, as the construction machine used in the above-described method for constructing a building foundation according to the present invention, for example, there is provided a vehicle body capable of traveling on the ground, and the vehicle body includes an excavating means for excavating a groove in the ground. It is sufficient to provide a stirring means for stirring the earth and sand in the excavated groove, a spraying means for spraying the cement in the groove, and a pressing means for pressing the earth and sand in the groove.

As the vehicle body, the same one as that of the existing construction machine can be used, as long as it can travel with a crawler (infinite track) or wheels. The excavating means is a mechanism for excavating a shovel or a belt-shaped cutter, and the stirring means is a dedicated stirrer (plow-shaped or rotary impeller type).
Alternatively, a shovel or the like may be used as a pressing means, such as a dedicated press device (a flat surface having a flat lower surface and pressurizable by hydraulic pressure, a device capable of further pressurizing by vibration, or the like) or a device using the lower surface of the shovel.

With this configuration, each step of the above-described basic construction method can be processed by one unit, and the complexity and wasted time for replacing the construction machine to be used as in the related art can be eliminated. Work efficiency can be improved.

Further, as a construction machine of a building foundation, the vehicle body further includes a ground bearing measuring means for measuring a ground bearing of a bottom surface in the groove compacted by the pressing means, and a precast on the bottom surface in the groove. A configuration may be employed in which a suspension means for suspending and carrying in the concrete foundation block from outside is installed. Here, as the ground strength measuring means, existing instruments for measuring the hardness of the ground can be used, for example, a means for measuring a resistance force when a bar-shaped member is inserted into the ground can be used, and as a suspending means, May use an existing boom crane or the like as appropriate.

With this configuration, it is possible to measure the bearing capacity after the above-described excavation, stirring, and pressing to confirm whether the solidified layer has sufficient strength. The work of suspending and installing the foundation block foundation can also be performed continuously, so that the work efficiency can be further improved.

[0037]

Embodiments of the present invention will be described below with reference to the drawings. FIGS. 1 to 4 show a first embodiment of the present invention. In FIG. 1, a building foundation 10 constructed according to the present embodiment has a lower portion buried and installed in a ground 12 on which a building 11 is built, and supports the building 11 in a fixed manner.

The building foundation 10 is formed by connecting a plurality of foundation blocks 100 made of precast concrete. Each base block 100 has a leg portion 101 extending horizontally at the lower portion, and has an inverted T-shaped cross section in which a rising portion 102 is vertically connected at the center of the upper surface, and is continuous over a predetermined length in the orthogonal direction in FIG. Things. Adjacent ones of these foundation blocks 100 are joined together and integrated to form the building foundation 10. Bolts and nuts for connecting the reinforcing members or cement for fixing the surfaces of the members are used for the mutual joining.

The building foundation 10 is buried in the ground 12 so that the entire leg 101 of the foundation block 100 and the lower part of the rising part 102 are buried. For this, the ground 1
2, a groove 13 is formed in accordance with the installation position of the building foundation 10, and a solidified layer 1 on which a leg 101 is placed at the bottom of the groove 13.
4 are formed, and a solidified layer 14 and a filling layer 15 that fills and covers both side surfaces of the rising portion 102 above the leg portion 101 are formed above the groove 13.

The solidified layer 14 is obtained by mixing cement into earth and sand generated when the trench 13 is dug, and squeezing the cement into the bottom of the trench 13 to flatten the upper surface. At this time, it is preferable to appropriately stir the mixture so that the earth and sand and the cement are sufficiently mixed. The earth and sand may be pulverized or the like before mixing the cement according to the quality and particle size thereof, or may be dried or water-adjusted so as to have a water suitable for hardening the cement. And it is desirable to squeeze so that the solidification strength enough to receive the building foundation 10 may be obtained. When the ground is excavated to form a groove, a pair of opposing side walls are formed so as to be gradually inclined inward toward the lower side, and cement is added to the soil in the groove to make it flat. The solidified layer is formed so as to be in close contact with the side wall surface.

The filling layer 15 is taken out of the earth and sand generated when the trench 13 is dug, except for the portion used for the solidified layer 14, around the trench 13, and after the solidified layer 14 and the foundation block 100 are installed, It is formed by backfilling the removed earth and sand. This filling layer 15 may be made of only earth and sand, or may be mixed with cement to be solidified. Further, the solidified layer 15 is spread thinly over the entire lower surface of the building 11. The portion may be concrete or the like.

The dimensions of the building foundation 10 are 600 mm in depth, 600 mm in bottom width, and 300 m in thickness of the solidified layer 14.
m, thickness 50 of the lower part of the building 11 (outside the groove 13) of the packed layer 15
mm. When the solidified layer 14 having such a thickness is formed, there is almost no excess of earth and sand dug out of the groove 13 except for the portion used for the filling layer 15.

In constructing the building foundation 10 as described above, a construction machine as shown in FIG. 2 is used. In FIG. 2, the construction machine 20 includes a vehicle body 21 having crawlers 210 (crawler tracks, trademark caterpillars, etc.) on both sides and capable of running on uneven terrain. It should be noted that a wheel may be used for traveling instead of a crawler.

At one end of the vehicle body 21, a narrow shovel 22 (digging means) suitable for excavating the groove 13 and a stirring roller 23 (stirring means) suitable for stirring earth and sand in the groove 13 are provided. ing. A cockpit 24 and a crane 25 (suspension means) are installed near the same side end of the vehicle body 21. Further, a cement hopper 2 is provided at an intermediate portion of the vehicle body 21.
6 (spraying means), pressing means 27, ground strength measuring means 28
Is installed. Also, at the other end of the vehicle body 21,
A blade 29 (which is installed in a so-called bulldozer; which is a ground leveling means and a sediment sweeping and collecting means) for collecting earth and sand while leveling the ground 12 is provided.

The shovel 22 is supported by the vehicle body 21 via an arm 220. The arm 220 is rotatably supported by the vehicle body, and is driven by a drive mechanism 221 such as a hydraulic cylinder to move up and down on the distal end side. The shovel 22 is rotatably supported at the tip of an arm 220 and has a drive mechanism 222 such as a hydraulic cylinder.
And the groove 13 can be excavated in the ground 12.

The stirring roller 23 is for stirring earth and sand on the peripheral surface by rotation, and may be of any existing shape in which the earth and sand are well caught on the peripheral surface. Those formed, or those formed by rolling a large number of protrusions on the peripheral surface of a cylindrical core to form a roll brush are used. The stirring roller 23 has an arm 230
Through the vehicle body 21. The arm 230 is rotatably supported by the vehicle body, and is driven by a drive mechanism 231 such as a hydraulic cylinder to be moved up and down on the distal end side. Thus, the stirring roller 23 can be retracted above the ground 12 and can be introduced into the groove 13. The rotation drive of the stirring roller 23 is performed on the vehicle body 2.
1 is performed by a hydraulic drive device or the like (not shown) provided in the apparatus 1.

The crane 25 has an arm 250 extending obliquely upward from the one side of the vehicle body 21 to the other side, and a telescopic extension 251 is provided at the tip thereof, and the telescopic extension 251 is provided at the tip thereof. Hook 25 with free wire 252
3 are suspended. The extension portion 251 is driven to expand and contract to an appropriate length by driving means such as a built-in hydraulic cylinder. The hook 253 can be moved up and down by winding up and pulling out the wire 252 with a winch or the like (not shown). Thereby, the base block 100 stacked on the surrounding ground 12 or the truck bed can be lifted and can be hung at another arbitrary position.

At the tip of the arm 250 and the tip of the extension 251, telescopic rods 254, 25 which extend and contract with hydraulic cylinders as auxiliary load receiving mechanisms between the arm and the vehicle body 21, respectively.
5 are installed. Of these, the extensible rod 254 is simultaneously extended and retracted when the tip of the arm 250 is raised and lowered, and the extensible rod 255 is simultaneously extended and retracted with the elevation of the tip of the arm 250 and the extension and contraction of the extension 251 to share the downward load at each end. It is designed to sufficiently bear the weight of the base block 100 that is loaded and hung on the hook 253. The ends of the rods 254 and 255 are pivotally connected to perform the above-described operation.

The cement hopper 26 stores cement powder replenished from the top, collects the powder in a funnel-shaped portion, and sprays the powder from below. A stirring mechanism 260 such as an impeller is installed at a spray outlet portion. At the time of spraying, the condensed portion of the cement powder is pulverized, so that fine powdery cement can be uniformly spread over a wide range. The pressing means 27 includes the vehicle body 2
A press plate 270 having a flat lower surface is provided on the lower surface side of the device 1. The press plate 270 is driven up and down below the vehicle body 21 by driving means such as a hydraulic device (not shown) to compact soil and the like in the grooves 13 of the ground 12. It is possible. As the press means 27, a vibration means (an existing excitation method such as an air-type reciprocating piston or a rotating eccentric weight type) that applies vibration to the press platen 270 may be added.

The ground strength measuring means 28 is an existing instrument for measuring the hardness of the ground. Here, a measuring bar 280 extending below the vehicle body 21 and the measuring bar 280 are advanced and retracted downward. A drive mechanism 281 such as a hydraulic cylinder, and an operating load of the drive mechanism 281,
0 is provided with measuring means (not shown) for measuring the rigidity of the ground from the resistance at the time of piercing into the ground and measuring the resistance force at the time of being inserted into the ground. The measuring rod 280 can reach the solidified layer 14 in the groove 13.

The blade 29 is supported by the vehicle body 21 via an arm 290. The arm 290 is rotatably supported by the vehicle body, and is driven by a drive mechanism 291 such as a hydraulic cylinder to move up and down on the distal end side. Thus, if the vehicle body 21 is run with the blade 29 lowered and along the ground 12, it is possible to level the surface of the ground 12 and scrape excess soil and the like.

Next, a procedure for constructing the above-described building foundation 10 using the construction machine 20 as described above will be described with reference to FIGS. First, as shown in FIG. 3A, the construction machine 20 is guided to the construction position of the building foundation 10 on the ground 12, and the construction machine 20 travels in the direction of the groove 13 while excavating the groove 13 using the shovel 22. Then, a continuous groove 13 is formed. At this time, the excavated earth and sand is left in the groove 13.

Then, as shown in FIG. 3 (B), when the agitating roller 23 approaches the groove 13 as the vehicle travels, the agitating roller 23 at the rear in the traveling direction is lowered to agitate the earth and sand dug in the groove 13. . In addition, the cement hopper 26 is
When it approaches, the hopper 26 is operated and the cement is sprayed on the stirred earth and sand in the groove 13. Similarly, when the pressing means 27 approaches the groove 13, the pressing means 27 is lowered and the earth and sand in the groove 13 on which the cement has been sprayed is compacted. As shown in FIG. 3C, when the groove 13 is excavated to a predetermined end position, the shovel 22, the stirring roller 23, and the cement hopper 2
6. The operation of the press means 27 is stopped, and the press means 27 is pulled out of the groove 13 as appropriate. As a result, a solidified layer 14 formed by staking earth and sand and cement over the entire length is formed in the groove 13.

Next, as shown in FIG.
Is driven in the opposite direction to the conventional one, and
When the groove reaches the groove 13, it is lowered and the hardness of the solidified layer 14 is inspected. Then, if the hardness is insufficient, the pressing means 27 located rearward in the running direction additionally performs tamping. During this time, the ground strength measurement and the compaction may be repeated by returning back as needed. As a result, the solidified layer 14 has the necessary hardness.

Then, as shown in FIG. 4 (B), when returning to the excavation side end of the groove 13, a truck or the like on which the base block 100 is loaded is brought close to the construction machine 20, and the base block 100 on the loading platform is removed. Lift with a crane 25. Specifically, the extension part 251 of the crane 25 is extended (the telescopic rod 255 also extends), the wire 104 hung on the basic block 100 is hooked on the hook 253, and the arm 250 is raised while winding the wire 252 (the telescopic rod 254, 255 is extended), and the base block 100 is lifted. Then, the suspended basic block 100 is arranged above the groove 13, the wire 252 is unwound while the arm 250 is lowered, and the basic block 100 is placed on the solidified layer 14.
Is placed.

After the base block 100 is set on the solidified layer 14 from one end to the other end, the trench 13 is filled with earth and sand so that the solidified layer 14 or the lower part of the basic block 100 is covered. In this work, the blade 2 of the construction machine 20 is used.
9 may be used. As described above, one block of building foundation 1
0 is completed, and similar construction is continuously performed on the adjacent ground 12, and when all the sections are completed, the building foundation 10 is completed.

According to the present embodiment, the following effects can be obtained. First, a strong solidified layer 14 formed by squeezing a mixture of earth and sand and cement can be formed on the bottom of the groove 13 where the building foundation 10 is installed. For this reason, it is possible to obtain a desired strength without using a conventional split stone. As a result, conventional problems associated with the use of split stones (geological problems, work efficiency problems, material use efficiency problems)
Can be solved.

In particular, since the solidified layer 14 is formed by adding cement to the earth and sand in the groove 13 and squeezing the solidified material, the solidified layer 14 is solidified and integrated at the bottom of the groove 13 and does not sink as in the conventional split stone. Therefore, a reliable building foundation 10 can be formed even on defective ground. Moreover, even when the earth and sand dug out of the groove 13 is soft mud, etc., a strong solidified layer can be formed by adjusting the mixing ratio of the cement.

Thus, the problem of geology such as defective ground can be solved.

Further, by eliminating the use of split stones as in the prior art, complicated work such as laying split split stones can be eliminated, and the problem of work efficiency can be solved. And the solidified layer 1
4 uses the soil excavated from the groove 13 and also uses the backfill for fixing the building foundation 10 so that the groove 1 can be used.
Most of the earth and sand dug out from 3 can be used for the building foundation 10, and there is no need to wastefully discard it. As described above, the earth and sand dug in the groove 13 can be effectively reused, and there is no need to use a separate split stone, so that the problem of material use efficiency can be solved.

Next, in this embodiment, since the foundation is formed by arranging the foundation blocks 100 made of precast concrete, it is not necessary to cast the foundation in place. For this reason,
The process after the solidification of the solidified layer 14 can be performed efficiently, and the working efficiency of the entire foundation construction can be improved. Also, in this embodiment, each step of the foundation work (excavation,
Stirring, cement spraying, press tamping, ground strength measurement, foundation block installation) can be executed by one construction machine 20, and construction machines such as those using various construction machines as in conventional foundation construction Can be eliminated, eliminating the complexity of replacing such machines,
Work efficiency can be improved.

Further, in the present embodiment, each step of the above-described foundation work can be continuously executed by the construction machine 20, and no waste time is generated between the steps.
Work efficiency can be further improved. In particular, the steps of excavation, agitation, cement application, and press compaction can be performed simultaneously in one run, and the working time can be further reduced.

Further, in this embodiment, additional compaction can be performed while measuring the ground strength of the solidified layer 14, and the strength of the solidified layer 14 and thus the building foundation 10 can be ensured.

In the construction machine 20 of this embodiment, since the crane 25 is reinforced by the telescopic rods 254 and 255, even the heavy base block 100 can be reliably lifted. The construction machine 20 according to the present embodiment can be configured using the vehicle body 21 of the existing construction machine and each mechanism, and can be easily implemented.

In the first embodiment, the construction machine 20
In the first run, each step of excavation or press compaction is executed, in the second reverse run, the ground strength is measured and additional compaction is performed, and the foundation block 100 is installed in the third travel. However, all of these steps may be performed in one run. By doing so, it is not necessary to turn over at the end, and construction with higher continuity is possible.

Also, the first drilling, stirring, and the second
Spraying and re-mixing cement in the third time, compacting and soil resistance measurement in the 3rd time, and setting the foundation block may be performed. In this way, the re-mixing after the cement is sprayed to improve the mixing property between cement and soil. As a result, the strength of the solidified layer 14 can be increased.

However, even in the spraying after stirring as in the above-described embodiment, since the cement sprayed into the gap between the earth and sand, the strength of the solidified layer 14 can be sufficiently obtained, and the ground strength measurement and additional compaction can be performed. By securing the strength of the solidified layer 14 and then installing the foundation block 100, the securing of the foundation strength is ensured. Therefore, the procedure as in the first embodiment is most suitable.

In the first embodiment, the construction machine 20
Although a means for executing all the steps from excavation to installation of the foundation block is provided, a part thereof may be omitted, and a separate machine may be brought into place. For example, the crane 25 of the construction machine 20 may be omitted, and the base block 100 may be installed by another crane vehicle. Since this process is the last of the foundation work, the construction machine 2
0 may be introduced after it has been moved to another position, and there is no problem of mechanical replacement.

Further, the ground strength measuring means 28 may be omitted, and this step can be easily performed by an inspection by an operator, and does not particularly lower the workability.

FIGS. 5 to 7 show a second embodiment of the present invention. As shown in FIG. 5, in this embodiment, similarly to the first embodiment, the lower part of the building 11
Of the building foundation 30 for fixedly supporting the building.
In the building foundation 30 of the present embodiment, the same base block 100 as that of the first embodiment is used, and a groove 33 is dug and buried in the ground, but the shapes of the groove 33 and the solidified layer 34, the construction machine 40 to be used, and the construction The procedure is different from the first embodiment.

In the groove 33 of this embodiment, the solidified layer 34 is formed so as to be narrower than the portion above the solidified layer 34 so as to have a stepped shape. That is, the groove 33 is provided on the ground 12 with a first groove 33 of 200 to 300 mm.
Dig 1 (700mm bottom width) and 200-300m on the bottom
The second groove 332 (bottom width 500 mm) of m 2 is formed by digging. The solidified layer 34 is formed in the second groove 332.

As shown in FIGS. 6A and 6C, the construction machine 40 according to the present embodiment is obtained by adding an excavation stirring roller to an existing power shovel or the like. In particular,
The construction machine 40 has a rotatable pedestal 403 on a trolley 402 that can travel on both crawlers 401, and a cockpit 404 and a shovel arm 405 are installed on the pedestal 403.

The excavator arm 405 is rotatably supported at its base end and can be swung so as to move up and down by the driving means 406 such as a hydraulic cylinder.
7 can also be bent and swung by driving means 408 such as a hydraulic cylinder. A shovel 409 is rotatably connected to the shovel arm 405, and the shovel 409 can swing by a driving unit 410 such as a hydraulic cylinder. The shovel 409 can form the first groove 331 in the ground 12 (digging means).

The excavation stirring roller 41 is provided at the rear end of the carriage 402.
1 is installed. The excavating and stirring roller 411 is for stirring the excavated soil and the like while excavating the ground on the peripheral surface by rotation (also serves as an excavating means and a stirring means),
The existing shape is adopted in which sediment is strongly caught on the peripheral surface. For example, a cylindrical cage formed by combining rods and the like and having a projection for excavation on the peripheral surface, or a cylindrical core having a large number of projections planted on the peripheral surface thereof is used.

The excavating and stirring roller 411 is supported by the carriage 402 via the arm 412. The arm 412 is rotatably supported by the vehicle body, and is driven by a drive mechanism 413 such as a hydraulic cylinder to move up and down on the distal end side. Excavation stirring roller 41
1 is driven by a hydraulic drive device or the like (not shown) provided on the carriage 402. Excavation stirring roller 411
Is normally held upward, but by rotating it downward, the second groove 332 is formed on the bottom surface of the first groove 331.
Can be formed (see FIG. 6C).

Next, a procedure for constructing the above-described building foundation 30 using the construction machine 40 described above will be described with reference to FIGS. First, as shown in FIG. 6A, the construction machine 40 is guided to the construction position of the building foundation 10 on the ground 12, and the first groove 331 is excavated using the shovel 409. At this time, the excavated earth and sand is taken out from the groove 331 and piled up on the nearby ground 12 (fill 121). By sequentially moving while performing this excavation, the building foundation 4
A series of grooves 331 corresponding to 0 are formed.

Next, as shown in FIG.
A cement bag 420 is hung from the tip of 9 via a wire or the like, held on the first groove 311, and its lower part is cut open to spray the cement 421. The cement 421 is spread all over the bottom surface of the first groove 311 by sequentially moving while performing the cement spraying. Subsequently, FIG.
As shown in (C), the rotary pedestal 403 is turned to turn the shovel arm 405 to the side to secure the front and rear views, and the construction machine 40 is guided to straddle the first groove 331, and Is introduced into the first groove 331, and the second groove 332 is excavated on the bottom surface of the groove 331. By this excavation, the excavated earth and sand 122 is dispersed in the cement 42 previously dispersed on the bottom surface of the first groove 331.
1 and mixed and stirred.

While the mixing and stirring are being performed, the first groove 331 is formed.
By sequentially moving the construction machine 40 along
As shown in FIG. 6D, a second groove 332 is formed on the bottom surface of the first groove 331 over the entire length.
3 is formed. At this time, in the second groove 332, the earth and sand 122 mixed with cement rises partially to the inside of the first groove 331 and is filled. The swelling of the earth and sand 122 is mainly caused by the increase in the gap between the earth and sand due to the mixing and stirring.

Next, as shown in FIG.
Is guided to one end of the groove 33, and the shovel 409 is guided to the inside of the groove 33.
And go. By sequentially moving the construction machine 40 along the groove 33 while performing the tamping, the solidified layer 34 filled and solidified in the second groove 332 in the groove 33 as shown in FIG. Is formed.

Then, the base block 100 is placed on the upper surface of the solidified layer 34 by another crane truck or the like, and the earth and sand previously set as the embankment 121 are backfilled.
A building foundation 30 as shown in FIG. 5 is formed.

According to this embodiment, the following effects can be obtained. That is, the groove 33 for installing the building foundation 30
A solidified layer 34 formed by squeezing a mixture of earth and sand and cement can be formed on the bottom surface of the solid. For this reason, it is possible to obtain a desired strength without using the conventional split stone, and to solve the conventional problems (geological problems, work efficiency problems, material use efficiency problems) associated with the use of split stone. This can be solved (see the first embodiment).

Also, in this embodiment, since the base block 100 made of precast concrete is used, similarly to the first embodiment, it is not necessary to cast the foundation in place, and the work efficiency of the entire foundation construction is improved. be able to.

On the other hand, in this embodiment, each step of the foundation work (the excavation of the first groove 331, the application of the cement, the second groove 332
Excavation, agitation, and compaction) can be performed by one construction machine 40, and then the foundation block 100 can be hung by a crane truck or the like. It is possible to eliminate the replacement of the construction machine as in the case of using a machine, to eliminate the complexity of such a machine replacement, and to improve the working efficiency.

The present invention is not limited to the above embodiments, and the present invention includes the following modifications. That is, as the cement used in the present invention, existing various cements may be used, and the compounding ratio may be adjusted according to the water content, hardness, etc. of the earth and sand excavated from the trench.

The dimensions and the like of the groove are not limited to the dimensions in the above-described embodiments, and may be appropriately selected for the implementation. For example, when more stability is required on soft ground, adjustments may be made such as increasing the groove width and increasing the bottom area of the solidified layer.

Further, the present invention is not limited to the above-described first and second embodiments in which the cement is simultaneously mixed with the excavation of the trench, but the earth and sand may be taken out after the excavation, mixed with cement outside the trench, and returned into the trench. By doing so, it is possible to easily prepare a necessary and sufficient amount of earth and sand for the solidified layer by adjusting the amount of earth and sand mixed with cement, and when returning the mixture of cement and earth and sand into the trench. Therefore, the thickness of the solidified layer can be easily adjusted.

Further, in the first embodiment, the soil excavated from the groove 13 is backfilled to form the filling layer 15, but cement may be mixed outside the groove 13 and solidified similarly to the solidified layer 14. In this way, a firm foundation fixation is possible. Alternatively, the solidified layer 14 may be mixed with cement outside the groove 13.

Further, the construction machine used in the present invention is not limited to the dedicated construction machine having all the mechanisms corresponding to the respective steps of the foundation construction as in the first embodiment, but may be the second construction machine.
Some steps such as ground strength measurement may be manually performed as in the embodiment. Also, as in the second embodiment,
The construction machine may be a general-purpose machine or the like obtained by adding a mechanism for excavation and stirring to an existing power shovel.For example, a so-called stabilizer that performs excavation and stirring may be appropriately provided with a cement spraying unit, a tamping unit such as a press or a stamper, or the like. It may be additionally used.

The means for executing each of these steps may be appropriately selected from existing equipment and used as long as the function can be ensured.

The foundation to which the present invention is applied is not limited to a continuous foundation (general cloth foundation) made of precast concrete and having an inverted T-shaped cross section as in the above embodiments. That is, the horizontal legs at the lower part of the foundation and the vertical rising parts at the upper part may be provided as separate precast blocks and joined at the time of installation on site. Also, the section may be formed in an inverted T-shape using cast-in-place concrete. However, on the basis of the above-mentioned inverted T-type precast block foundation, on-site construction can be performed most efficiently.

Further, the present invention is not limited to the inverted T-shape, but may be an approximately I-shape in which the legs are omitted, or a substantially inverted Y-shape in which the rising portion gradually expands. Further, each basic block is not limited to a continuous base but may be an independent base that is partially independent. However, in general buildings, continuous foundations are frequently used. In addition, the planar shape of the foundation formed on the ground may be appropriately set according to the building constructed on the upper part, and the building constructed on the upper part is a prefabricated type (box type unit type) for a house or an apartment. , Panel type, frame type panel type, etc.) or various buildings by a conventional construction method can be arbitrarily selected.

[0092]

As described above, according to the present invention,
Digging the ground for building a building, forming a groove corresponding to the foundation of the building so that a pair of opposing side wall surfaces is gradually inclined inward as going downward, and the soil in the groove is formed. By forming the solidified layer so as to be in close contact with the side wall surface by adding cement and flattening the solidified layer, it is possible to ensure the strength even with a poor ground such as softness. In addition, it is possible to eliminate the complexity of the construction as in the case of the conventional split-stone foundation, thereby improving the working efficiency. Further, the excavated earth and sand can be effectively used, and the material use efficiency can be improved.

[0093] In addition, by making it possible to execute the processes such as excavation of trenches, spraying of cement, tamping, and installation of precast concrete foundation blocks with the same machine, the complexity of replacing machines as in conventional foundation construction is increased. Can be eliminated. In particular, by continuously performing the processing of each step while running the construction machine including each means for executing each step, the working efficiency can be greatly improved as compared with the case where each step is sequentially performed.

[0094] By using a construction machine equipped with excavating means, stirring means, cement dispersing means, pressing means for compaction, and means for installing a precast concrete foundation block, the above-described series of basic construction steps can be performed in the same manner. The processing can be continuously performed by the machine, and the improvement of the working efficiency including the elimination of the replacement of the machine can be surely promoted. In addition, the construction machine is equipped with earth bearing capacity measuring means and suspension means so that the inspection of the solidified layer and the loading of the precast concrete foundation block can be processed by the same machine. Can be further promoted.

[Brief description of the drawings]

FIG. 1 is a sectional view showing a basic structure of a first embodiment of the present invention.

FIG. 2 is a schematic side view showing the construction machine of the first embodiment.

FIG. 3 is a schematic view showing the first half of the process of the foundation work of the first embodiment.

FIG. 4 is a schematic view showing the latter half of the basic construction process of the first embodiment.

FIG. 5 is a sectional view showing a basic structure of a second embodiment of the present invention.

FIG. 6 is a schematic diagram showing the first half of the process of foundation work of the second embodiment.

FIG. 7 is a schematic view showing the latter half of the basic construction process of the second embodiment.

FIG. 8 is a sectional view showing a modification of the present invention.

FIG. 9 is a schematic view showing a conventional foundation construction.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 10 Building foundation 100 Precast concrete foundation block 11 Building 12 Ground 13 Groove 14 Solidified layer 15 Filled layer 20 Construction machine 21 Car body 22 Excavator which is excavating means 23 Stirring roller which is stirring means 25 Crane which is suspending means 26 Spraying means Cement hopper 27 which is a pressing means 28 Ground strength measuring means 29 Blades which are earth and sand sweeping means and ground leveling means 30 Building foundation 33 Groove 331 First groove 332 Second groove 34 Solidified layer 40 Construction machine 402 Dolly 405 Excavation Excavator arm 409 as a means Excavator 411 as a digging means Excavating and stirring roller serving as both digging means and stirring means

──────────────────────────────────────────────────続 き Continuation of the front page (56) References JP-A-63-277316 (JP, A) JP-A-4-330112 (JP, A) JP-A-4-185820 (JP, A) JP-A-5-185 17955 (JP, A) JP-A-63-138016 (JP, A) JP-A-63-63816 (JP, A) JP-A-54-107937 (JP, U) (58) Fields investigated (Int. ⁷ , DB name) E02D 3/12 102 E02D 3/046 E02F 5/02

Claims (2)

(57) [Claims] 1. A ground for constructing a building is excavated to form a groove corresponding to a foundation of the building, and a pair of opposing side walls are formed by:
Formed so as to gradually inward as it goes downward, add cement to the earth and sand in the groove, squeeze it flat and form a solidified layer in close contact with the side wall surface,
When constructing the foundation of the building on the solidified layer, the step of excavating the trench, the step of adding the cement, and the tamping step are performed using the same construction machine. A construction mechanism is installed, and the construction machine is run along the ground on which the foundation of the building is to be installed, and the respective steps are continuously performed during the running of the construction machine. Method. 2. Excavating the ground for building a building, forming a groove corresponding to the foundation of the building, and forming a pair of opposing side walls,
It is formed so as to gradually inward as it goes downward, and cement is added to the earth and sand in the groove to squeeze it flat to form a solidified layer close to the side wall surface,
In constructing the foundation of the building on the solidified layer, the same construction machine is used for excavating the trench, adding the cement, compacting, and installing the precast concrete foundation block on the solidified layer. The construction machine is provided with a mechanism for processing the respective steps, and the construction machine is caused to travel along the ground on which the foundation of the building is to be installed. A construction method for building foundations that is performed continuously.