CN209745726U - Miniature indoor static sounding test system - Google Patents
Miniature indoor static sounding test system Download PDFInfo
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- CN209745726U CN209745726U CN201920314107.1U CN201920314107U CN209745726U CN 209745726 U CN209745726 U CN 209745726U CN 201920314107 U CN201920314107 U CN 201920314107U CN 209745726 U CN209745726 U CN 209745726U
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- 238000012360 testing method Methods 0.000 title claims abstract description 60
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- 239000000523 sample Substances 0.000 claims abstract description 118
- 239000000835 fiber Substances 0.000 claims abstract description 92
- 239000002689 soil Substances 0.000 claims abstract description 43
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Abstract
The utility model discloses a miniature indoor static sounding test system belongs to the civil engineering field. The precision to traditional electricity survey static sounding test device is not enough, and the interference killing feature is poor, is not suitable for indoor test scheduling problem, the utility model provides an utilize fiber grating sensor as the miniature static sounding probe of measuration part to the injection device of improvement static sounding makes it have the characteristics that the precision is high, the interference killing feature is strong. The utility model discloses mainly including probe part, injection device and ambient temperature case three, utilize the fiber grating sensor to survey the part as the inside high accuracy measurement of probe, given fiber grating strain value and the relational expression of not drainage shear strength to utilize the test of a plurality of not unidimensional probes injection simultaneously, provided the preferred method who obtains indoor ocean weak soil not drainage shear strength.
Description
Technical Field
The utility model belongs to the civil engineering field relates to a static sounding testing arrangement and method, especially relates to an utilize fiber grating sensor as the ocean weak soil strength test method of part of measurationing.
Background
Static sounding is used as a test and exploration means, the shear strength, the sensitivity and the like of a test soil body can be obtained according to a test result, test parameters of soil body engineering properties are evaluated so as to judge and evaluate the bearing and stability characteristics of a foundation, and the current static sounding test technology is widely applied to field test exploration of ocean soft soil.
while the static sounding method is widely applied in tests, some problems also exist, for example, the error of the test result of the marine soft soil and the ultra-soft soil is large due to the problems of small area of the sounding cone tip, large test range and the like, and the use requirement cannot be met. On the other hand, the field test is limited by the influence of the test environment, the penetration rate and the verticality are difficult to guarantee, and meanwhile, the test precision of the traditional resistance-type sensor is easily interfered by factors such as water, temperature, salinity, electromagnetism and the like, and the problems become main influence factors influencing the test accuracy of the static sounding method. Aiming at the problems, it is important to provide a static sounding test system and method with high test precision and strong anti-interference capability.
The utility model provides a miniature indoor static sounding test system and method utilizes not unidimensional probe to carry out the static sounding test, regard the probe size that is most suitable for indoor ocean weak soil test as preferred, the influence of the all kinds of uncertain factors of reducible field test, utilize simultaneously that corrosion resistance is good, the interference killing feature is strong, the fiber grating that the precision is high, stability is good is as the strain test original paper, to improving the measuring accuracy, the physical mechanics characteristic of accurate reflection test soil sample has important meaning.
SUMMERY OF THE UTILITY MODEL
the utility model aims to provide a miniature indoor static sounding test system and method to overcome the not enough of current means. The fiber bragg grating with high precision, strong anti-interference capability and good corrosion resistance is used as a stress measurement means in the probe, and meanwhile, a preferred method for obtaining the non-drainage shear strength of the ocean soft soil is provided.
The technical scheme of the utility model:
a miniature indoor static sounding test system comprises a probe, a hollow probe rod 16, a pore-adjustable movable slider 17, a slider positioning bolt 18, a fiber grating wavelength demodulator 19, a test soil sample 20, a linear module 21, a stepping motor 22, an environmental temperature box 23 and a temperature sensor 24; the probe comprises a deformation column 1, a fiber grating inclination measuring sensor base 2, a friction sleeve 3, a conical tip 4, a fiber grating strain gauge 5, a probe rod joint 6, a fiber grating inclination measuring sensor 7, a pore water valve core 8, a flexible filter screen I9, a sealing head 10, an optical cable 11, a sealing ring I12, a sealing ring II 13, a sealing ring III 14 and a flexible filter screen II 15;
a through hole is formed in the middle of the deformation column 1, so that an optical cable 11 can conveniently penetrate through the through hole; the upper part of the deformation column 1 has a small diameter, and the middle lower part of the deformation column has a large diameter; two pairs of grooves are arranged on the middle column body, the two pairs of grooves are distributed up and down, each pair of grooves is symmetrically arranged in the radial direction of the deformation column 1, and the lower part of the deformation column 1 is axially provided with a cavity to provide a placing space for the fiber grating inclinometer 7;
The outer side of the middle lower part of the deformation column 1 is sleeved with a friction sleeve 3, the upper end of the friction sleeve 3 extends to the small-diameter part of the deformation column 1, and the lower end of the friction sleeve exceeds the lower end of the deformation column 1; the deformation column 1 is in threaded connection with the friction sleeve 3, the fiber grating strain gauges 5 are arranged in the grooves, and a pair of fiber grating strain gauges 5 positioned above can obtain a strain value under the combined action of conical tip resistance and side wall friction resistance; a pair of fiber bragg grating strain gauges 5 positioned below can obtain strain values of conical tip resistance;
The upper part of the deformation column 1 is sleeved with a probe rod joint 6, the probe rod joint 6 is in a three-stage stepped shaft shape, the diameters of the stepped shafts at two ends are small, the diameter of the middle stepped shaft is large, and the outer diameter of the middle stepped shaft is consistent with that of the friction sleeve 3; a stepped shaft at the lower end of the probe rod joint 6 is inserted into a gap between the deformed column 1 and the upper end of the friction sleeve 3 to realize fixed connection, and a flexible filter screen II 15 is arranged between a shaft shoulder of the probe rod joint 6 and the upper end surface of the friction sleeve 3 to allow pore water to enter and provide a space for the deformed column 1 to deform to a certain degree; the upper end of the deformation column 1 and the upper end of the probe rod joint 6 are sealed through a sealing head 10, and the sealing head is used for preventing water from entering to influence the properties of the deformation column;
The lower end of the deformation column 1 is connected with a fiber bragg grating inclination measuring sensor base 2; the fiber grating inclinometer sensor base 2 is a convex cylinder, the diameter of the lower half cylinder is small, the diameter of the upper half cylinder is large, and the diameter of the upper half cylinder is consistent with the diameter of the middle lower part of the deformation column 1; the upper end of the fiber bragg grating inclination measuring sensor base 2 is fixed with a fiber bragg grating inclination measuring sensor 7, and the fiber bragg grating inclination measuring sensor 7 is located in a cavity at the lower part of the deformation column 1 and used for measuring the inclination angle of the probe; the lower end of the fiber bragg grating inclination measuring sensor base 2 is connected with the pore water valve core 8 and used for blocking external pore water from entering and transmitting the conical tip resistance to the deformation column 1;
The lower end of the friction sleeve 3 is provided with a conical tip 4, the conical tip 4 is coated on the outer side of the lower half cylinder of the fiber grating inclination measuring sensor base 2 and is in threaded connection with the pore water valve core 8, and the conical tip resistance can be ensured to be finally transmitted to the deformation column 1; a flexible filter screen I9 is arranged between the conical tip 4 and the friction sleeve 3, so that pore water is allowed to enter, and a space is provided for the deformation of the deformation column 1 to a certain degree;
A first sealing ring 12 is sleeved on the upper half cylinder of the fiber bragg grating inclinometer sensor base 2 and used for preventing water at the first flexible filter screen 9 from continuously entering to influence the properties of the deformation column 1; a second sealing ring 13 is arranged at the joint of the deformation column 1, the friction sleeve 3 and the probe rod joint 6 and is used for preventing water from entering to influence the property of the deformation column 1; a third sealing ring 14 is arranged at the junction of the deformation column 1, the probe rod joint 6 and the sealing head 10;
the optical cable 11 comprises an optical fiber for transmitting the inclination angle information of the fiber grating inclinometer sensor 7 and an optical fiber for transmitting the deformation information of the fiber grating strain gauge 5, and is used for transmitting the information measured by the probe to the fiber grating wavelength demodulator 19;
The lower end of the hollow probe rod 16 is in threaded connection with the upper end of a probe rod joint 6 of the probe, and the upper end of the hollow probe rod 16 is in threaded connection with a pore adjustable moving slide block 17 and is used for driving the hollow probe rod 16 to move along a cross rod so as to realize static sounding of different points;
the hole is formed in the hole-adjustable movable sliding block 17 and can be used for leading the optical cable 11 out to the fiber bragg grating wavelength demodulator 19 through the hole, and the upper part of the hole-adjustable movable sliding block 17 is fixed on a cross rod of the linear module 21 through a sliding block positioning bolt 18;
The stepping motor 22 is connected with the linear module 21 and can drive the linear module 21 to move in the vertical direction; then the probe enters an environmental temperature box 23 with an opening at the top end and finally penetrates into the test soil sample 20;
The temperature in the ambient temperature box 23 is adjustable, and a temperature sensor 24 is arranged in the ambient temperature box for measuring the temperature in the soil sample 20. The temperature environment change of the seabed soft soil is simulated by changing the temperature condition, so that the influence of the temperature on the static sounding test can be researched, and the reliability of the test is improved.
The probes are distributed on the disc in a spiral line according to the size sequence.
when the probe penetrates downwards, the strain of the lower end fiber grating strain gauge 5 and the sectional area of the deformation column and the bottom area of the cone tip 4 are used for obtaining the resistance of the cone tip, the strain of the upper end fiber grating strain gauge 5 and the side area of the friction sleeve 3 are used for obtaining the frictional resistance of the side wall, namely the strain value of the lower end of the deformation column 1 is the strain generated by the resistance of the cone tip, and the strain value of the upper end is the strain generated by the combined action of the resistance of the cone tip and the frictional resistance of the side wall; the soil body can be classified by utilizing a known related empirical formula of a static sounding test and the non-drainage shear strength of the soil body is obtained, and the properties of the ocean soft soil, such as sensitivity, softening index, thixotropy and the like, can be obtained on the basis of the non-drainage shear strength; through the static cone penetration test of the probes with a plurality of sizes, different accuracies and ranges, the probe size which best meets the accuracy and the range of the static cone penetration test of the ocean soft soil is taken as the optimization.
A micro indoor static sounding test method comprises the following steps:
(1) When the probe penetrates downwards, calculating the cone tip resistance through the strain reading of the fiber bragg grating strain gauge 5 at the lower end, and obtaining the non-drainage shear strength according to the cone tip resistance value:
In the formula: qc is cone tip resistance; a is the sectional area of the lower end of the deformed column 1; e is the elastic modulus of the deformed column 1; epsilon 1 is the reading of the lower fiber grating strain gauge 5; a1 is the bottom area of the cone tip 4; kq is the calibration coefficient of the cone tip resistance.
And then calculating the shear strength Su without draining water.
In the formula: su is the non-drainage shear strength of the ocean soft soil; σ vo is the total overburden stress; nk is an empirical coefficient, the value of Nk is 11-20, and the average value is 16.
(2) Establishing an algorithm formula of a fiber bragg grating strain value and soft soil non-drainage shear strength:
the precision and the range of the required soft soil non-drainage shear strength can be preliminarily determined by substituting the formula according to the precision and the range of the fiber bragg grating strain gauge 5 and the probe parameters.
(3) When the probe penetrates downwards, the side wall friction is calculated through the strain reading of the upper end fiber grating strain gauge 5, and the soil type is determined according to the side wall friction:
in the formula: fs is a standard value of side wall frictional resistance; a' is the sectional area of the upper end of the deformed column 1; e is the elastic modulus of the deformed column 1; epsilon 2 is the reading of the fiber bragg grating strain gauge 5 at the upper end; a2 is the sidewall area of the friction sleeve 3; kf is the side wall friction force calibration coefficient.
And (4) solving the value of the friction ratio according to the friction ratio in the specification according to the side wall friction force fs and the cone tip resistance force qc, and determining the type of the soil.
(4) The fiber grating inclination sensor 7 inside the probe measures the deflection angle (relative to the plumb line) of the feeler lever for correcting the penetration amount, thereby obtaining the property of the soil at the real depth. When the deflection angle is measured for 1 time every penetration of 1m, the penetration correction quantity of the section is as follows:
In the formula: and delta hi is the ith section penetration depth correction amount, and theta i-1 are actually measured deflection angles of the ith time and the (i-1) th time. The penetration depth of each section can be corrected through the formula, and the true value of the penetration depth is obtained.
(5) the characteristic errors of the grating fiber sensor 7, i.e. the errors due to the strain transfer losses in the adhesive layer and the protective layer between the fiber grating strain gage 5 and the deformation column 1, need to be considered, as shown in the established model of fig. 5. Deducing a relation between a true strain value of the deformation column 1 and a strain error generated by the fiber grating strain gauge 5 by using a material mechanics method:
in the formula: and delta epsilon is the strain error of the fiber grating, epsilon is the real strain of the deformation column 1, h is the thickness of the strain transfer layer, d is the contact width of the optical fiber and the strain transfer layer, l is the initial length of the bonding section of the optical fiber, G is the shear modulus of the strain transfer layer, E' is the elastic modulus of the optical fiber, and A0 is the cross-sectional area of the optical fiber.
the relation between the strain error delta epsilon of the fiber grating and the thickness h of the strain transfer layer and the length l of the bonding section of the optical fiber is drawn by using the relation, as shown in FIG. 6. It can be seen that in order to reduce the strain error of the fiber grating, the thickness of the adhesive layer should be reduced and the length of the bonded optical fiber segment should be increased.
(5) since the size of the probe will affect its accuracy and range, a preferred test of the probe size is required: according to the sequence of the sizes from large to small, a plurality of probes with different precisions and ranges are fixed on a disc from inside to outside by a spiral line and are simultaneously penetrated, the non-drainage shear strength measured by each probe is obtained, the probe size with the precision and the range which are most suitable for the marine soft soil test is taken as the optimization, and the non-drainage shear strength of the marine soft soil is further obtained by the optimization method, as shown in figure 7.
in order to avoid the boundary effect of the model box during the indoor test (the distance between the center of the probe and the wall of the model box is more than 10 times of the diameter of the probe), the probes are distributed on the disc in a spiral line according to the size sequence. The precision and the range of the probe can be estimated according to the precision and the range of the used fiber bragg grating strain gauge, for example, probes with different sizes and the theoretical ranges of 2kpa, 5kpa, 10kpa, 20kpa, 30kpa and 40kpa are arranged, the precision and the range of the probe are optimal to ocean soft soil according to the theoretical ranges of the probes with the non-drainage shear strength precision of 0.01kpa, 0.025kpa, 0.05kpa, 0.1kpa, 0.15kpa and 0.2 kpa. In the same way, probes with different side wall areas can be arranged for testing. Through the steps, the size of the probe with the range and the precision meeting the indoor ocean soft soil test can be selected as the optimal size, and finally the probe with the optimal size is used for the static sounding test.
The utility model has the advantages that:
the utility model adopts the high-precision, corrosion-resistant and anti-interference fiber grating strain gauge and the fiber grating inclination measuring sensor as the measuring component inside the probe to replace the electrical measuring technology, thereby avoiding the adverse effect on the test result in the complex environment and increasing the result reliability of the measurement on the ocean soft soil; the method for measuring the cone tip resistance at the lower end and the cone tip resistance and the side wall friction resistance at the upper end of the fiber grating strain gauge on the deformation column is adopted, the problem of measuring a plurality of quantities is solved, and meanwhile, the inclinometer sensor is also applied to increase the reliability and the accuracy of data, so that the utility model has diversified functions; a preferable method for obtaining the non-drainage shear strength of the soft soil at the ocean is provided, namely, the optimal probe size is obtained through optimization, so that the finally required value of the non-drainage shear strength is very accurate.
Drawings
Fig. 1 is a miniature indoor static sounding test device provided by the embodiment of the utility model.
fig. 2 is a longitudinal cross-sectional view of a static cone penetration probe in an apparatus provided by an embodiment of the present invention.
fig. 3 is a cross-sectional view of a static cone penetration probe a-a in an apparatus according to an embodiment of the present invention.
fig. 4 is a top view of a static cone penetration probe in an apparatus provided by an embodiment of the present invention.
FIG. 5 is a diagram of a model of strain transfer within the probe.
FIG. 6(a) is a graph of strain error of a fiber grating as a function of strain-transmitting layer thickness.
FIG. 6(b) is a graph of the strain error of a fiber grating as a function of the length of the fiber bond segment.
Figure 7 is a schematic diagram of the apparatus for optimizing probe size.
Fig. 8 is a top view of the disk.
In the figure: 1, deforming the column; 2, a fiber bragg grating inclinometer sensor base; 3 rubbing the sleeve; 4, conical tip; 5, a fiber bragg grating strain gauge; 6, a probe rod joint; 7, a fiber bragg grating inclination measuring sensor; 8 pore water valve core; 9, a flexible filter screen I; 10 sealing the head; 11 an optical cable; 12, a first sealing ring; 13, a second sealing ring; 14, sealing ring III; 15, a flexible filter screen; 16 a hollow probe; 17 an aperture adjustable movable slide block; 18 slide positioning bolts; 19 fiber grating wavelength demodulator; 20 testing soil sample; 21 a linear module; 22 a stepper motor; 23 ambient temperature cabinet; 24 temperature sensor.
Detailed Description
for better understanding of the technical solution of the present invention, the following detailed description is made in conjunction with the accompanying drawings and specific embodiments.
The first embodiment is as follows:
A miniature indoor static sounding test system and a test method. The device comprises a deformation column 1, a fiber bragg grating inclination measuring sensor base 2, a friction sleeve 3, a conical tip 4, a fiber bragg grating strain gauge 5, a probe rod joint 6, a fiber bragg grating inclination measuring sensor 7, a pore water valve core 8, a flexible filter screen I9, a sealing head 10, an optical cable 11, a sealing ring I12, a sealing ring II 13, a sealing ring III 14, a flexible filter screen II 15, a hollow probe rod 16, a pore adjustable movable sliding block 17, a sliding block positioning bolt 18, a fiber bragg grating wavelength demodulator 19, a test soil sample 20, a linear module 21, a stepping motor 22, an environmental temperature box 23 and a temperature sensor 24.
the deformation column 1 is deformed when being penetrated; the fiber grating inclination measuring sensor base 2 is used for stabilizing the fiber grating inclination measuring sensor; a friction sleeve 3 for transmitting side wall friction force; the cone tip 4 is used for transmitting cone tip resistance; the fiber bragg grating strain gauge 5 is used for measuring the strain magnitude of the deformation column; the probe rod joint 6 is used for connecting the probe rod and the probe; the fiber bragg grating inclination measuring sensor 7 is used for measuring the inclination angle of the probe; the pore water valve core 8 is used for blocking external pore water from entering; the flexible filter screen I9 is used for keeping a gap between the cone tip and the sleeve and providing a space for deformation of the deformation column; a sealing head 10, a waterproof watertight connector; the optical cable 11 is used for transmitting static sounding information obtained by the probe; the first sealing ring 12, the second sealing ring 13 and the third sealing ring 14 are O-shaped sealing rings; the flexible filter screen II 15 is used for keeping a gap between the joint and the sleeve and providing a space for deformation of the deformation column; a hollow probe 16 for connecting the probe and the penetration device; the pore adjustable moving slide block 17 is used for moving along the cross rod to realize static sounding at different points; a slider positioning bolt 18 for fixing the slider; the fiber grating wavelength demodulator 19 is used for demodulating wavelength information transmitted by the probe; a test soil sample 20 for a soil sample for an indoor test; a linear module 21 for moving the connected cross bar up and down to achieve penetration and return; a stepping motor 22 for providing power for penetration and return; the environment temperature box 23 is used for changing the temperature of the sample soil sample so as to simulate different temperature environments; the temperature sensor 24 is used for measuring the temperature of the test soil sample;
One end of the deformation column 1 is in threaded connection with the probe rod joint 6, the middle of the deformation column is in threaded connection with the friction sleeve 3, the other end of the deformation column is in tight connection with the fiber grating inclination measurement sensor base 2, the pore water valve core 8 is fixed below the fiber grating inclination measurement sensor base 2, the pore water valve core 8 is in threaded connection with the conical tip 4, and the above structures form the main structure of the probe.
The fiber bragg grating strain gauges 5 are respectively attached to the upper end and the lower end of the threaded connection part of the deformation column 1 and the friction sleeve 3, when the probe downwards penetrates into the test soil sample 20 in a quasi-static mode, the widths of the first flexible filter screen 9 and the second flexible filter screen 15 are reduced due to compression, the deformation column at the lower end is deformed due to the resistance of the conical tip, and the magnitude of the force can be analyzed through the lower end strain gauges. The deformation of the upper end strain gauge is caused by the combined action of the cone tip resistance and the side wall friction resistance, so that the deformation of the lower end strain gauge is subtracted from the deformation of the upper end strain gauge to obtain the deformation of the strain gauge caused by the side wall friction resistance.
the fiber grating inclinometer sensor 7 is tightly connected with the fiber grating inclinometer sensor base 2, so that the stability can be ensured, and the fiber grating inclinometer sensor 7 can be used for correcting the penetration depth by monitoring the inclination angle of the probe in real time.
The fiber bragg grating inclinometer sensor base 2 is sleeved with a first sealing ring 12 for preventing water at the first flexible filter screen 9 from continuously entering to influence the property of the deformation column 1; a second sealing ring 13 is arranged at the joint of the deformation column 1, the friction sleeve 3 and the probe rod joint 6 and is used for preventing water from entering to influence the property of the deformation column 1; and a third sealing ring 14 is arranged at the junction of the deformation column 1, the probe rod joint 6 and the sealing head 10 and is used for preventing water from entering to influence the property of the deformation column 1.
The optical fiber connected with the fiber grating strain gauge 5 and the fiber grating inclination measuring sensor 7 is arranged in the optical cable 11, and information carried by the optical fiber is transmitted to the fiber grating wavelength demodulator 19 through the optical cable 11, so that the aim of recording the data of the whole static sounding process in real time is fulfilled.
the stepping motor 22 drives the linear module 21 to move, and then drives the static sounding probe to move in the vertical direction, that is, the part outside the probe is equivalent to the penetration device and the transmission device, so that the probe can complete two actions of penetrating into the soil sample 20 and returning.
the strain reading of the fiber bragg grating sensor in the probe and the preferably obtained related parameters of the probe can be substituted into the following formula to obtain the non-drainage shear strength of the test soil sample. In the penetration process, the strain value of the lower end of the probe is transmitted into a demodulator to obtain epsilon, the cross section area and Young modulus of a deformed column are respectively A and E, and the base area of a conical tip is A'. The depth of penetration can be corrected by an inclinometer sensor, from which the total overburden stress σ vo is determined. The empirical coefficient Nk can be obtained by using the specification, and the calibration coefficient kq can be obtained by using a calibration test. The non-drainage shear strength Su of the test soil sample is:
Claims (2)
1. A miniature indoor static sounding test system is characterized by comprising a probe, a hollow probe rod (16), a pore-adjustable movable slider (17), a slider positioning bolt (18), a fiber grating wavelength demodulator (19), a test soil sample (20), a linear module (21), a stepping motor (22), an environmental temperature box (23) and a temperature sensor (24); the probe comprises a deformation column (1), a fiber grating inclination measuring sensor base (2), a friction sleeve (3), a conical tip (4), a fiber grating strain gauge (5), a probe rod joint (6), a fiber grating inclination measuring sensor (7), a pore water valve core (8), a flexible filter screen I (9), a sealing head (10), an optical cable (11), a sealing ring I (12), a sealing ring II (13), a sealing ring III (14) and a flexible filter screen II (15);
a through hole is formed in the middle of the deformation column (1) so that an optical cable (11) can conveniently penetrate through the through hole; the upper part of the deformation column (1) has a small diameter, and the middle lower part of the deformation column has a large diameter; two pairs of grooves are arranged on the middle column body, the two pairs of grooves are distributed up and down, each pair of grooves is symmetrically arranged in the radial direction of the deformation column (1), and the lower part of the deformation column (1) is axially provided with a cavity to provide a placing space for the fiber bragg grating inclination measuring sensor (7);
a friction sleeve (3) is sleeved on the outer side of the middle lower part of the deformation column (1), the upper end of the friction sleeve (3) extends to the small-diameter part of the deformation column (1), and the lower end of the friction sleeve exceeds the lower end of the deformation column (1); the deformation column (1) is in threaded connection with the friction sleeve (3), the fiber grating strain gauges (5) are arranged in the grooves, and a pair of fiber grating strain gauges (5) positioned above can obtain a strain value under the combined action of conical tip resistance and side wall friction resistance; a pair of fiber bragg grating strain gauges (5) positioned below can obtain strain values of conical tip resistance;
The upper part of the deformation column (1) is sleeved with a probe rod joint (6), the probe rod joint (6) is in a three-stage stepped shaft shape, the diameters of the stepped shafts at two ends are small, the diameter of the middle stepped shaft is large, and the outer diameter of the middle stepped shaft is consistent with the outer diameter of the friction sleeve (3); a stepped shaft at the lower end of the probe rod joint (6) is inserted into a gap between the deformed column (1) and the upper end of the friction sleeve (3) to realize fixed connection, and a flexible filter screen II (15) is arranged between a shaft shoulder of the probe rod joint (6) and the upper end surface of the friction sleeve (3) to allow pore water to enter and provide a space for the deformed column (1) to deform to a certain degree; the upper end of the deformation column (1) and the upper end of the probe rod joint (6) are sealed through a sealing head (10) and used for preventing water from entering to influence the property of the deformation column;
the lower end of the deformation column (1) is connected with a fiber bragg grating inclination measuring sensor base (2); the fiber grating inclinometer sensor base (2) is a convex cylinder, the diameter of the lower half cylinder is small, the diameter of the upper half cylinder is large, and the diameter of the upper half cylinder is consistent with the diameter of the middle lower part of the deformation column (1); the upper end of the fiber bragg grating inclination measuring sensor base (2) is fixed with a fiber bragg grating inclination measuring sensor (7), and the fiber bragg grating inclination measuring sensor (7) is located in a cavity at the lower part of the deformation column (1) and used for measuring the inclination angle of the probe; the lower end of the fiber bragg grating inclination measuring sensor base (2) is connected with a pore water valve core (8) and used for blocking external pore water from entering and transmitting cone tip resistance to the deformation column (1);
The lower end of the friction sleeve (3) is provided with a conical tip (4), the conical tip (4) is coated on the outer side of the lower half cylinder of the fiber grating inclination measuring sensor base (2) and is in threaded connection with the pore water valve core (8), and the resistance of the conical tip can be ensured to be finally transmitted to the deformation column (1); a flexible filter screen I (9) is arranged between the cone tip (4) and the friction sleeve (3) to allow pore water to enter and provide a space for the deformation of the deformation column (1) to a certain degree;
a first sealing ring (12) is sleeved on the upper half cylinder of the fiber bragg grating inclinometer sensor base (2) and used for preventing water at the first flexible filter screen (9) from continuously entering to influence the property of the deformed column (1); a second sealing ring (13) is arranged at the joint of the deformed column (1), the friction sleeve (3) and the probe rod joint (6) and is used for preventing water from entering to influence the property of the deformed column (1); a third sealing ring (14) is arranged at the junction of the deformation column (1), the probe rod joint (6) and the sealing head (10);
The optical cable (11) comprises an optical fiber for transmitting inclination angle information of the fiber grating inclination measuring sensor (7) and an optical fiber for transmitting deformation information of the fiber grating strain gauge (5), and is used for transmitting information measured by the probe to the fiber grating wavelength demodulator (19);
the lower end of the hollow probe rod (16) is in threaded connection with the upper end of a probe rod joint (6) of the probe, and the upper end of the hollow probe rod (16) is in threaded connection with a pore adjustable moving slide block (17) and is used for driving the hollow probe rod (16) to move along a cross rod so as to realize static sounding at different points;
The hole is formed in the hole-adjustable movable sliding block (17) and can be used for leading the optical cable (11) out to the fiber grating wavelength demodulator (19) through the hole, and the upper part of the hole-adjustable movable sliding block (17) is fixed on a cross rod of the linear module (21) through a sliding block positioning bolt (18);
The stepping motor (22) is connected with the linear module (21) and can drive the linear module (21) to move in the vertical direction; then the probe enters an environmental temperature box (23) with an opening at the top end and finally penetrates into the test soil sample (20);
the temperature in the environment temperature box (23) is adjustable, and a temperature sensor (24) is arranged in the environment temperature box and used for measuring the temperature in the test soil sample (20).
2. a micro indoor static cone penetration test system according to claim 1, wherein the probes are distributed on the disc in a spiral line in order of size.
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| CN201920314107.1U CN209745726U (en) | 2019-03-13 | 2019-03-13 | Miniature indoor static sounding test system |
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Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109839317A (en) * | 2019-03-13 | 2019-06-04 | 大连理工大学 | A kind of micro indoor static cone penetration test system and method |
| CN117661528A (en) * | 2023-11-29 | 2024-03-08 | 中国科学院武汉岩土力学研究所 | Novel static sounding test device based on hyperspectral imaging technology |
-
2019
- 2019-03-13 CN CN201920314107.1U patent/CN209745726U/en not_active Withdrawn - After Issue
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN109839317A (en) * | 2019-03-13 | 2019-06-04 | 大连理工大学 | A kind of micro indoor static cone penetration test system and method |
| CN109839317B (en) * | 2019-03-13 | 2020-08-14 | 大连理工大学 | Miniature indoor static sounding test system and method |
| CN117661528A (en) * | 2023-11-29 | 2024-03-08 | 中国科学院武汉岩土力学研究所 | Novel static sounding test device based on hyperspectral imaging technology |
| CN117661528B (en) * | 2023-11-29 | 2024-06-11 | 中国科学院武汉岩土力学研究所 | Static cone penetration test device and method based on hyperspectral imaging technology |
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