JPH041392A - Column erection - Google Patents

Abstract

PURPOSE:To discriminate the existence or non-existence of embedded objects exactly and save labor by excavating ground hydraulically after radar investigation on ground, to insert a bore hole radar antenna into a hole for the radar investigation on ground, and by excavating an excavating hole to be widened to form a final diameter and to erect a column. CONSTITUTION:With a radar measuring equipment 2, from a ground level, an electromagnetic wave 2a is shot in ground 3, and the existence or non-existence of an embedded object 4 in the ground 3 is investigated. After that, a paved section 3a is cut out with a core cutter, and with a water jet machine 5, an excavating hole 6 is excavated. After that, a pipe 9 is inserted, and into an internal cavity, a bore hole radar antenna 8 is inserted, and in the peripheral direction of the excavating hole 6, an electromagnetic wave 8a is shot, and the embedded object 4 is investigated. Then, with a bore cutter 7, the paved section is excavated to be widened, and with an earth auger drill 10, the excavating hole 6 is widened to enlarge a diameter, and a column erecting hole 11 is obtained to erect a column. As a result, a reliable investigation result is obtained, and excavation excellent in safety can be executed.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Field of Application J] The present invention relates to a pole construction method for excavating a hole (hereinafter referred to as a "pole construction hole") for erecting a utility pole into the soil, particularly in an urban area or the like.

[Conventional technology] An earth auger drill is usually used to drill a hole for pillar construction, but in urban areas where buried objects such as gas pipes and water pipes are laid in a complicated manner, it is difficult to drill holes using this earth auger drill. Due to the risk of damage, the current practice is to proceed with excavation work while searching for buried objects by hand.

However, since the depth of the pillar hole is required to be approximately 2 to 3 meters, manual digging requires a large excavation space due to the stepped trench, and a large amount of excavated soil comes out, making it difficult to dig the hole. It is necessary to secure a certain amount of space around the area.

In addition, if you hit a buried object during excavation, you will have to change the excavation location and start digging again, making the previous work a waste of time. It would require a tremendous amount of effort to remove and repair it.

[Problems to be Solved by the Invention] In recent years, in view of such circumstances, radar exploration from the ground of buried objects in the soil has been carried out in advance before excavation.

This laser exploration method emits electromagnetic waves from the ground surface into the soil, and measures the reflection information caused by the electromagnetic waves traveling in the soil causing refraction and reflection phenomena at buried objects with a dielectric constant different from that of the soil. This is a method of detecting the position of objects.

However, with this conventional buried object radar detection method, accurate exploration is difficult because some buried objects have a dielectric constant similar to that of soil, and detection errors occur as the distance from the ground increases. That is the current situation.

Therefore, according to such conventional radar exploration methods, if an underground zone is explored from the surface and a preliminary exploration result indicating that there are no buried objects is obtained, a borehole of the final target diameter (for example, , 450φ), but if a buried object is hit, the work of searching and excavating another location will be repeated. In addition, in drilling using this radar exploration method,
The effort and time spent on post-processing such as repair work and filling in excavation holes where there was an error in exploration, which poses a huge risk of damaging underground water pipes, gas pipes, etc. This resulted in a huge amount of waste.

The present invention was made in view of the above circumstances, and it is possible to eliminate waste of excavation labor by more accurately determining the presence or absence of buried objects when excavating a pillar hole. It is an object of the present invention to provide a method for constructing pillars that does not cause damage to buried objects such as pipes or gas pipes even if they hit them.

[Means to solve the problem]

The above problems are solved by the present invention, which includes the following steps. That is, primary exploration to detect the presence or absence of buried objects in the depth direction using ground radar exploration, primary excavation to obtain a small-diameter borehole to the final depth by hydraulic salting of the surveyed soil, and borehole radar installed in the borehole. Insert an antenna and conduct a radar search for the presence or absence of buried objects in the circumferential direction of the borehole 2
Next exploration: Secondary drilling to enlarge the drilled hole to its final diameter.

A pillar construction method characterized by sequentially edging.

[Effect]

The present invention detects the presence or absence of buried objects in the soil through the above-mentioned primary and secondary radar exploration, and after each buried object exploration, performs primary excavation in the depth direction and secondary excavation to further enlarge the excavated hole. This method is characterized by excavating a hole for pillar erection.

First, in the primary exploration, the presence or absence of buried objects in the depth direction is investigated by ground radar exploration.

Next, the locations where a tentative exploration result with no buried objects was obtained through the primary exploration are excavated to the final depth using hydraulic salting (primary excavation). Since this excavation is carried out using hydraulic salting, even if there is a buried object during excavation due to a survey error, the buried object such as water pipes or gas pipes will not be damaged.
The installation status can be maintained.

In addition, the diameter of the hole created by this excavation can be small enough to ensure the insertion of a borehole radar antenna during secondary exploration, and even if there is a mistake in exploration and the hole needs to be filled, it does not require much effort and waste can be kept to a minimum.

Note that the secondary exploration is a radar survey for the presence or absence of buried objects in the circumferential direction of the hole created by the primary excavation.
During the primary excavation, it is essential to excavate to the final depth required for the pillar erection.

The secondary exploration is performed by inserting a borehole radar antenna into the hole created by the primary excavation.

According to this secondary radar exploration, it is possible to explore at close range in the circumferential direction of the borehole by primary excavation, so that much more reliable exploration results can be obtained than in ground radar exploration.

If the secondary exploration results show that there are no buried objects in the circumferential direction of the excavation hole, the hole is enlarged to the final diameter required for the pillar erection, and thus a pillar erection hole of the predetermined diameter and predetermined depth is obtained. It will be done.

[Example] Embodiments of the present invention will be described below with reference to the drawings.

Figures 1 fal to fe] are diagrams showing the process of exploration and excavation by the pillar construction method of the present invention, with a final diameter of 450φ,
A specific example of excavating a pillar hole with a final depth of 3 m will be shown.

First, in Fig. 1fal, electromagnetic waves 2a are transmitted from the ground location where the pole is planned to be erected by the radar measurement system 2.
is fired in the depth direction of the soil 3 to search for the presence or absence of buried objects in the soil (first exploration completed). If it is found in this ground radar survey that there is no buried pipe 4 such as a water pipe or gas pipe, the paved portion 3a is cut out with a core cutter (not shown), as shown in Fig. 1 fb). , a hydraulic trench with a smaller diameter of 200φ than the final diameter is excavated to a final depth of 3 m using the jet fountain 5 to obtain an excavated hole 6 (first excavation completed).

Next, as shown in FIG. Antenna 8 is inserted, and N magnetic waves 8a are emitted in the circumferential direction of the excavated hole 6 to conduct buried object exploration up to an approximately 600φ range (secondary exploration). When the exploration result that there is no buried object in the soil 3 in the circumferential direction of the excavation hole is obtained, the vibrator 9 is removed from the excavation hole 6, and as shown in FIG.
The paved portion is expanded using a φ bore cutter 7, and then, as shown in Figure 1, a 450 φ earth auger drill 10 is used to drill a 450 φ hole in the 3 m deep excavation hole 6 created by the above excavation to create a pillar erection hole. 11 is obtained (secondary excavation completed), and a pillar is erected in the pillar erecting hole 11 obtained in this way by a normal method.

r Effects of the invention] As explained above, according to the pillar erection method of the present invention, the presence or absence of buried objects in the depth direction is detected by ground radar exploration, and then the excavation hole is drilled to the final depth required for the pillar erection. However, this excavation is based on hydraulic excavation that will not damage buried objects even if it hits a buried object during excavation, so there is no possibility of unforeseen situations in which excavation occurs at the location of the buried object. can be handled safely, and filling up wasted drilling holes requires minimal effort.Furthermore, by conducting radar exploration in the circumferential direction of the drilling hole, more reliable exploration results than ground exploration can be obtained. By enlarging the small diameter hole to the final diameter required for pillar erection, the desired pillar erection hole can be obtained.

Therefore, it is possible to obtain much more reliable exploration results than the conventional ground exploration method, and it is also possible to carry out extremely superior excavation in terms of safety, making it safe and labor-saving, especially in urban areas where there are many dangerous buried objects. It is possible to obtain a pillar construction method that makes it possible to excavate a pillar hole.

BRIEF DESCRIPTION OF THE DRAWINGS FIGS. 1 fa) to tel are diagrams showing the process of exploration and excavation using the pillar erection method of the present invention.

Claims (1)

[Claims] (1) A pillar construction method in which the presence or absence of buried objects in the soil is investigated and a predetermined pillar erection hole is excavated, and the primary exploration is to search for the presence or absence of buried objects in the depth direction by ground radar exploration; Primary excavation to obtain a small-diameter excavation hole to the final depth by hydraulic excavation in the soil; Inserting a borehole radar antenna into the excavation hole and conducting a radar search for the presence or absence of buried objects in the circumferential direction of the excavation hole.2
A pillar erection method characterized by sequentially performing the following steps: secondary exploration, and secondary excavation for enlarging the excavated hole to its final diameter.