CN106404323B - Lamination shear model soil case is applied to when underground structure vibration bench test soil body horizontal to big displacement test method and device - Google Patents

Abstract

A method and device for testing large horizontal displacement of soil when a laminated shear type model soil box is applied to a shaking table test of an underground structure belong to the technical field of civil engineering. The device includes a laminated shear model box (1), a displacement test system (3), and the displacement test system (3) includes a displacement recording writing table (4), a displacement transmission device (5), a model box and a displacement measurement system Connecting device (6); wherein, the displacement transmission device (5) is fixedly connected with the laminated shearing model box (1), and is flexibly connected with the displacement recording writing table (4); the displacement recording writing table (4) passes through the model box The connection device (6) of the displacement measurement system is fixedly connected with the laminated shear model box (1); the present invention overcomes the difficulty in installing the contact displacement sensor in the model test and the non-contact displacement sensor has high requirements on imaging technology and needs post-processing The problem of data processing is simple, reliable and easy to implement.

Description

Soil level when stacked shear model soil boxes are used in shaking table tests of underground structures Large displacement test method and device

technical field

The invention belongs to the technical field of civil engineering, and relates to a method and a device for testing large horizontal displacement of soil when a laminated shear type model soil box is applied to a shaking table test of an underground structure.

Background technique

Large-scale rail transit construction makes it inevitable that the subway station structure will pass through the liquefiable soil layer. Since the 1980s, through a series of earthquake damage investigations, it has been concluded that the main cause of severe damage to buildings, bridges, dams, underground structures and other structures during earthquakes is the large lateral displacement caused by soil liquefaction. Only when the deformation caused by liquefaction It is enough to endanger the safety of buildings or cause harm when it is used normally. Therefore, the core of the research on liquefaction is the deformation development process. The research on the damage of structures caused by large ground displacements has gradually attracted widespread attention in the field of geotechnical seismic engineering in the world. From the development of seismic design methods at home and abroad, it can be seen that the guiding ideology of seismic design of underground structures has gradually developed from the traditional strength judgment to the design principle of deformation control (response displacement method), and soil deformation analysis has received more and more attention. .

Most of the measurement methods of the stress value in the test are essentially the measurement of the deformation value, and the measurement of the deformation is more intuitive than the measurement of the stress. According to the constitutive relationship of the material, it is easy to use the strain distribution to deduce the stress distribution, so the deformation measurement It plays a very important role in the model test.

However, due to the relative lag of measurement technology, in the dynamic test of soil, especially in the large-scale shaking table test of underground structure, the measurement of soil displacement has always been an urgent problem to be solved.

Contact measurement requires the test instrument to be fixed or attached to the surface of the measured structure, which brings many installation difficulties to practical applications, such as the commonly used pull-wire displacement gauges; non-contact displacement measurement technology is a new type of displacement measurement Compared with the conventional physical or mechanical displacement test method, the test method has the advantages of high test accuracy and can effectively eliminate the displacement test error caused by contact, but has the disadvantages of limited test point position and test range, such as laser displacement testing technology. In recent years, scholars have carried out research on the globalization and automatic displacement testing technology of photographs and dynamic videos collected by optical cameras combined with post-image processing. This method has high requirements for photography technology and certain requirements for post-processing technology. When considering Limited to larger displacements.

Existing studies have shown that the laminated shear model soil box can effectively reduce the constraints on the shear deformation of the soil, and the horizontal displacement of the square tubes in each layer of the box approximately represents the horizontal displacement of the soil layer. Therefore, the deformation of the soil can be approximated by obtaining the horizontal displacement of the square steel pipes of each layer of the box.

Contents of the invention

The object of the present invention is to provide a method and device for testing large horizontal displacement of soil when a laminated shear type model soil box with high reliability and visualized displacement test is applied to underground structure shaking table test. It overcomes the above-mentioned deficiencies and solves the measurement problem of large shear deformation of soil under vibration conditions.

The purpose of the present invention is achieved through the following technical solutions:

A laminated shear model box and a displacement test system, comprising a laminated shear model box 1, a displacement test system 3, the displacement test system 3 also includes a displacement record writing table 4, a displacement transmission device 5, a model box and a displacement test system Measuring system connecting device 6; wherein,

The displacement transmission device 5 is fixedly connected with the laminated shearing model box 1, and is flexibly connected with the displacement recording writing table 4; the displacement recording writing table 4 and the laminated shearing model box 1 pass through the model box and the displacement measurement system connecting device 6 The square steel pipe column 2 and the square steel pipe horizontal column 7 are fixedly connected through the laminated shear model box.

The displacement measurement system device 3 includes a displacement recording writing table 4 , a displacement transmission device 5 , a model box and a displacement measurement system connection device 6 . Wherein, one end of the displacement transmission strip 16 on the displacement transmission device 5 is fixed on the square steel pipe column 2 of the laminated shear model box, and the displacement recording pen 17 at the other end is in contact with the displacement recording board 14 on the displacement recording writing table 4, and the displacement recording is written. The table 4 is fixed on the model box and the displacement measurement system connection device 6 through the writing table fixing plate 8, the bottom of the model box and the displacement measurement system connection device 6 is connected with the square steel pipe column 2 of the bottommost laminated shear model box, and the top is Link to each other with square steel pipe cross column 7.

The displacement recording writing table 4 includes a writing table fixing plate 8, an adjustable speed motor 9, a motor mounting plate 10, a paper tape conveying upper roller 11, a paper tape conveying lower roller 12, a pre-adjustment conveying knob 13, and a displacement recording board 14, the paper tape smoothes the suppression pipe 15. The writing board 14 is the writing area of the displacement meter pen 17, on which a writable paper tape is placed, and the adjustable speed motor 9 drives the paper tape conveying upper roller 11 and the paper tape conveying lower roller 12 to move, and drives the paper tape to move at a constant speed through friction , flatten the suppression pipe 15 to ensure the smoothness of the paper tape.

When the square steel pipe column 2 of each layer of the laminated shearing model box moves, it drives the movement of the displacement transmission bar 16 and the displacement recording pen 17 on the displacement transmission device 5. Since the writing board 14 is placed with a writable paper tape, the displacement recording Pen 17 just records the displacement movement process of square steel pipe column 2 at a certain moment on the displacement transmission bar placed in advance on the writing board 14, because the adjustable speed motor 9 drives the paper tape to convey the upper roller 11 and the paper tape to convey the lower roll The shaft 12 moves, drives the paper tape through friction to make it move at a constant speed, and has a smoothing and suppressing tube 15 to ensure the smoothness of the paper tape, and records the actual movement and displacement process of the square steel pipe column 2 during the entire time period through the recording of the displacement recording pen 17 .

The beneficial effects of the present invention are:

The device overcomes the difficulties in the installation of contact displacement sensors in model tests and the high requirements for imaging technology and the need for post-data processing of non-contact displacement sensors, and approximates the deformation of the soil by obtaining the horizontal displacement of square steel pipes in each layer of the box. , to more intuitively record the actual dynamic changes of soil displacement in shaking table tests. It has the characteristics of simple structure, high reliability, easy implementation and enclosure, and is expected to be applied in other similar tests.

Description of drawings

Fig. 1 is a schematic diagram of the overall assembly of a laminated shear model box and a displacement testing system of the present invention;

Fig. 2 is an overall schematic diagram of a displacement testing system of the present invention;

Fig. 3 is a schematic diagram of a displacement recording writing table of the present invention;

Fig. 4 is a schematic diagram of a displacement transmission writing pen of the present invention;

Fig. 5 is a result figure of the embodiment of the present invention;

Reference signs:

1 Laminated shear model box 2 Laminated shear model box Square steel pipe column

3 Displacement test system 4 Displacement record writing table

5 Displacement transmission device 6 Model box and displacement measurement system connection device

7 Square steel pipe cross column 8 Writing table fixing plate

9 Adjustable speed motor 10 Motor mounting plate

11 Tape delivery upper roller 12 Tape delivery lower roller

13 Pre-adjustment delivery knob 14 Displacement recording plate

15 Paper tape smoothing and suppressing tube 16 Displacement transmission strip

17 displacement recording pen

Detailed ways

The present invention will be further described below in conjunction with the accompanying drawings and specific embodiments.

As shown in Figures 1-4, the laminated shear model soil box is used in the shaking table test of underground structures as a test device for large horizontal displacement of soil, including a laminated shear model box 1 and a displacement measurement system device 3 . The parts of the laminated shear model box 1 used in this invention include a square steel pipe column 2 and a square steel pipe cross column 7 .

As shown in FIG. 1 , FIG. 2 and FIG. 4 , the displacement measurement system device 3 includes a displacement recording writing table 4 , a displacement transmission device 5 , a model box and a displacement measurement system connection device 6 . Wherein, one end of the displacement transmission strip 16 on the displacement transmission device 5 is fixed on the square steel pipe column 2 of the laminated shearing model box, and the displacement recording pen 17 of the other end contacts the displacement recording plate 14 on the displacement recording writing table 4, and the displacement recording is written. The table 4 is fixed on the model box and the displacement measurement system connection device 6 through the writing table fixing plate 8, the bottom of the model box and the displacement measurement system connection device 6 is connected with the square steel pipe column 2 of the stacked shear model box at the bottom, and the top is Link to each other with square steel pipe cross column 7.

As shown in Figures 1 and 3, the displacement recording writing table 4 includes a writing table fixing plate 8, an adjustable speed motor 9, a motor mounting plate 10, a paper tape conveying upper roller 11, a paper tape conveying lower roller 12, a pre-adjustment Conveying knob 13, displacement recording board 14, paper tape smoothing and suppressing tube 15. The writing board 14 is the writing area of the displacement meter pen 17, on which a writable paper tape is placed, and the speed-adjustable motor 9 drives the paper tape transmission upper roller 11 and the paper tape transmission lower roller 12 to move, and drives the paper tape to move at a constant speed through friction , flatten the suppression pipe 15 to ensure the smoothness of the paper tape.

The device overcomes the difficulty in installing the contact displacement sensor in the model test and the high imaging technology requirements of the non-contact displacement sensor and the need for post-data processing. It can more intuitively record the actual dynamic changes of the soil displacement in the shaking table test. The characteristics of simplicity, high reliability, easy implementation and maintenance are expected to be applied in other similar experiments.

Under the action of sine waves, the horizontal displacement of a certain layer of square steel pipes in a laminated shear model soil box measured by the displacement test method in this note is the same as the displacement at the same position of the box measured by the non-contact displacement test method. There is only a slight difference in size, and the displacement trend is basically similar, indicating that the self-developed displacement test method has a good test effect, and at the same time overcomes the problems of the difficulty of fixing the pull-wire displacement gauge and the limited test range of the non-contact displacement gauge. It is used for the horizontal large displacement test of the soil during the shaking table test of the underground structure.

Finally, it should be noted that the above embodiments are only used to illustrate the technical solution of the present invention without limitation, although the present invention has been described in detail with reference to the preferred embodiments, those of ordinary skill in the art should understand that the technical solution of the present invention can be Modifications or equivalent substitutions without departing from the spirit and scope of the technical solutions of the present invention shall be included in the scope of the claims of the invention.

Claims (2)

1. When the laminated shear type model soil box is applied to the shaking table test of the underground structure, the horizontal large displacement test device of the soil body is characterized in that: It includes a laminated shear model box (1), a displacement test system (3), and the displacement test system (3) includes a displacement recording writing table (4), a displacement transmission device (5), a model box and a displacement measurement system connected device (6); wherein, The displacement transmission device (5) is fixedly connected with the laminated shearing model box (1), and is flexibly connected with the displacement record writing table (4); the displacement record writing table (4) is connected with the model box and the displacement measuring system ( 6) fixedly connected with the laminated shear model box (1); One end of the displacement transmission strip (16) on the displacement transmission device (5) is fixed on the square steel pipe column (2) of each layer of the laminated shear model box, and the other end is provided with a displacement recording pen (17); The pen (17) is in contact with the displacement recording plate (14) on the displacement recording writing table (4), and the displacement recording writing table (4) is fixed on the model box and the displacement measuring system connecting device (6) through the writing table fixing plate (8). ), the bottom of the model box and the displacement measurement system connecting device (6) is connected with the square steel pipe column (2) of the bottom laminated shear model box, and the top is connected with the square steel pipe horizontal column (7); Described displacement record writing table (4) comprises writing table fixed plate (8), adjustable speed motor (9), motor installation plate (10), paper tape conveys upper roller (11), paper tape conveys lower roller ( 12), pre-adjustment conveying knob (13), displacement recording board (14), paper tape smoothing and suppressing tube (15); one end of displacement recording board (14) is placed with paper tape transmission upper roller (11) and paper tape transmission The lower roller (12), the other end is provided with a paper tape smoothing and suppressing tube (15); The speed-adjustable motor (9) drives the movement of the paper tape conveying upper roller (11) and the paper tape conveying lower roller (12). 2. The method of applying the device according to claim 1, characterized in that: When the square steel pipe column (2) of each layer of the laminated shearing model box moves, it drives the movement of the displacement transmission bar (16) and the displacement recording pen (17) on the displacement transmission device (5), due to the writing board (14 ) is placed with a writable paper tape, and the displacement recording pen (17) will record the displacement movement process of the square steel pipe column (2) at a certain moment on the displacement transmission strip placed in advance on the writing board (14). The motor (9) drives the upper roller (11) and the lower roller (12) of the paper tape to move, and drives the paper tape to move at a constant speed through friction, and there is a smoothing and suppressing tube (15) to ensure the smoothness of the paper tape , the actual motion displacement process of the square steel pipe column (2) throughout the time period is recorded through the recording of the displacement recording pen (17).