CN201060186Y - A foundation and slope engineering model test platform - Google Patents

Abstract

The utility model discloses a foundation and slope engineering model test platform. There are instrument embedding holes and data lead-out holes on one side of the long side of the side steel plate of the main structure, and a visual window on the other side; water supply pipes are set in the gravel and sand cushion at the bottom of the rectangular steel structure model tank The pipe network is connected with the water tank and the vacuum pumping device; the short side of the side steel plate of the main structure is provided with drainage holes; The lower end of the reaction beam is equipped with a hydraulic jack, a spherical hinge, and a servo loading system consisting of a pressure plate; the displacement sensor, the earth pressure sensor and the pore water pressure sensor are connected to form a monitoring system. This test platform can be used to carry out model test research on various disaster-causing conditions and various reinforcement methods for foundation and slope engineering.

Description

A foundation and slope engineering model test platform

technical field

The utility model relates to a model test device used in the technical field of geotechnical engineering, in particular to a model test platform suitable for foundation and slope engineering.

Background technique

my country is a country where mountains and hills are widely distributed. Various slopes are often encountered during civil engineering construction, including natural slopes, excavated slopes and filled slopes. These slopes may be unstable and slide under various natural or man-made disaster conditions (such as heavy rain, rising water level, excavation, stacking, etc.), causing casualties and property losses. Due to the complex and diverse hazard-causing factors of the slope, its instability mode and catastrophe mechanism are very complex. In order to deeply understand the mechanism of slope disasters under complex environmental conditions, correctly evaluate the stability of slopes, and propose economical and effective disaster prevention (reduction) engineering measures, it is necessary to carry out large-scale landslide disaster simulation experiments for different geological conditions, revealing the slope Instability mode and catastrophe mechanism, comparison of dangerous slope reinforcement schemes, and verification of geotechnical engineering numerical analysis theory and software.

In addition, unfavorable geological conditions, such as soft clay foundation, are often encountered in the practice of foundation engineering. Soft ground treatment methods and technologies are one of the important geotechnical engineering topics in soft soil areas. The large-scale foundation model test can be used not only for the study of foundation deformation and instability mechanism, but also for the comparison and selection of weak foundation reinforcement schemes. This test platform can carry out large-scale model test research on surcharge preloading method, vacuum preloading method, IFCO forced consolidation method, flexible pile composite foundation, rigid pile foundation, etc. of weak foundations.

At present, the commonly used geotechnical model test methods at home and abroad include centrifugal model test and 1g model test. The advantage of the centrifugal model test is that the stress field of the prototype can be reproduced with a smaller model. The disadvantage is the size effect of soil particles. In addition, due to the small size of the model, the selection, arrangement and embedding of measuring instruments are more difficult. The size of the 1g geotechnical model test system reported in relevant literature is relatively small, and its function is relatively single (that is, one test system can only be used for single-factor disaster simulation test).

Contents of the invention

The purpose of the utility model is to overcome the deficiencies of the existing geotechnical model test technology, provide a foundation and slope engineering model test platform, so that it can simulate a variety of disaster-causing conditions, a variety of reinforcement methods of slope (or foundation) failure The stability process is revealed, the instability mode and catastrophe mechanism are revealed, and the basis for choosing economical and reasonable disaster prevention (reduction) engineering measures is provided.

The technical scheme that the utility model adopts is:

Including the rectangular steel structure model groove composed of the beams and columns of the main steel structure and the steel plate on the side of the main structure, the long sides of the steel plate on the side of the main structure are vertically arranged in multiple rows, and each row has a plurality of instrument embedding holes and data lead-out holes. On the other side of the long side of the side steel plate of the main structure, there are multiple rows vertically, and each row has multiple visible windows; in the gravel and sand cushion at the bottom of the rectangular steel structure model tank, there are multiple rows of windows with water outlets. Branch water pipe network, after the branch water pipe network with water outlets are connected to each other, several water pipes with first control valves are connected to hard water pipes, and then divided into two roads, one road passes through the second control valve and then connects to the water tank , and the other road passes through the third control valve and the fourth control valve and then connects to the vacuum pumping device; there are drainage holes on the short sides of the side steel plates of the main structure; the reaction beams are bridged on both sides of the long sides of the main steel structure beams and columns , there are buckles at both ends of the reaction beam. The reaction beam can slide along the long side and then be tightened with buckles. The lower end of the reaction beam is equipped with several hydraulic jacks controlled by the hydraulic control system. The sliding ends of the several jacks are respectively used A servo loading system composed of a spherical hinge and a pressure-bearing plate connection; the movable support of the displacement sensor is bridged on both sides of the long side of the beam column of the main steel structure, and several displacement sensors are arranged below the movable support of the displacement sensor. The movable support of the displacement sensor, Displacement sensors, earth pressure sensors and pore water pressure sensors are connected to form a monitoring system.

The water tank is suspended on the sliding track of the lifting bracket with a chain hoist, and a constant water head float valve is provided in the water tank to keep the water level constant.

The beneficial effect that the utility model has compared with background technology is:

(1) A variety of disaster-causing and reinforcement conditions can be generated, and there are many simulation functions, including heap loading, excavation, groundwater level changes, vacuum preloading, composite foundations, pile foundations, etc.;

(2) It can simulate slopes and foundations with different stratum combination conditions; the soil layer conditions, groundwater level, initial stress state and boundary conditions in the foundation and slope models are controllable and known;

(3) The size of the model tank is large (the inner size of the main model tank is 15m in length x 5m in width x 6m in height), and large-scale model tests can be carried out, and the size effect and boundary effect of the model test are small;

(4) The design of the vertical steel structure model groove makes it have good visibility (that is, the visual window) and facilitates the embedding of instruments and equipment;

(5) The monitoring system is comprehensive and integrated, which can realize automatic and real-time monitoring of multiple physical quantities; the monitoring instrument is relatively easy to embed, and the test operation is relatively simple;

(6) It has a movable reaction beam device, which is convenient for loading tests at different positions and combinations.

Description of drawings

Figure 1 is a schematic diagram of the test platform.

Fig. 2 is a schematic diagram of the He service loading device.

In the figure: 1. Beams and columns of the main steel structure, 2. Steel plates on the side of the main structure, 3. Instrument embedding holes, 4. Data cable lead-out holes, 5. Visual window, 6. Vacuum pumping device, 7. Water tank, 8. Normal Water head float valve, 9, hand chain hoist, 10, hose, 11, lifting bracket, 12, control valve, 13, positive and negative pressure gauge, 14, hard water pipe, 15, branch water pipe network with water outlet , 16. Gravel and sand cushion, 17. Drain hole, 18. Reaction beam, 19. Buckle, 20. Hydraulic jack, 21. Pressure plate, 22. Spherical hinge, 23. Displacement sensor movable support, 24. Displacement sensor, 25. Earth pressure sensor, 26. Pore water pressure sensor, 27. Slope model, 28. Hydraulic pipeline, 29. Hydraulic control system.

Detailed ways

As shown in Fig. 1 and Fig. 2, the utility model comprises a rectangular steel structure model groove composed of main steel structure beam column 1 and main structure side steel plate 2, and the inner bottom surface and four inner sides of the groove all adopt sealing measures to achieve No water leakage or air leakage during use; the inner wall of the side steel plate 2 of the main structure is specially smoothed to reduce side friction and boundary effects; the long sides of the side steel plate 2 of the main structure are vertically arranged in parallel 1. Each row has a plurality of instrument embedding holes 3 and data lead-out wire holes 4, so as to facilitate the embedding of monitoring instruments and the drawing of instrument signal lines; A plurality of side visible windows 5, through which the lateral displacement of the soil during the test can be observed and measured, special sealing measures are taken around the visible windows; gravel and sand at the bottom of the rectangular steel structure model groove The cushion layer 16 is provided with multiple rows of branch water pipe networks 15 with outlet holes, which can evenly distribute the water head at the bottom of the model tank; after the branch water pipe networks 15 with water outlet holes are connected to each other, after A water pipe with the first control valve 12 is connected with the hard water pipe 14 and then divided into two paths, one path is connected to the water tank 7 after the second control valve 12 and the flexible pipe 10, and the other path is passed through the third control valve 12 and the fourth control valve. 12 is followed by a vacuum pumping device 6, and the hard water pipe 14 is connected with a positive and negative pressure gauge 13; the third control valve 12 and the fourth control valve 12 are closed, and the second control valve 12 is opened, which can be controlled by controlling the height of the water tank The height of the groundwater level; the short side of the side steel plate 2 of the main structure is provided with a drainage hole 17, through which the water level in the model tank can be reduced by drainage; the reaction force is bridged on both sides of the long side of the main steel structure beam column 1 There are buckles 19 at both ends of the beam 18 and the reaction beam 18. The reaction beam 18 can slide along the long side and then be tightened and fixed with the buckle 19. 28 controls several hydraulic jacks 20 arranged in equal parts, and the sliding ends of several jacks 20 are respectively connected with spherical hinges 22 to the pressure bearing plate 21 to form a servo loading system. This buckle fixing method greatly facilitates the reaction beam 18 By changing the position of the reaction beam, loading can be carried out at different positions in the model according to the test requirements; the movable support 23 of the displacement sensor is bridged on both sides of the long side of the main steel structure beam column 1, and the movable support of the displacement sensor Below 23, there are several displacement sensors 24 equally arranged. The movable bracket 23 of the displacement sensor, the displacement sensor 24, the earth pressure sensor 25 and the pore water pressure sensor 26 are connected to form a monitoring system, which is connected with the automatic data acquisition system for Real-time monitoring and automatic recording of multiple physical quantities during model tests.

Said water tank 7 is suspended on the slide track of the lifting bracket 11 with chain hoist 9, and the water tank 7 is provided with a constant water head float valve 8 to keep the water level constant.

Embodiment: Now take the test of landslide caused by loading on the bank slope top of a river as an example to illustrate the use method of this test platform.

A slope model 27 with a certain slope and height is filled in the steel structure model groove of the test platform composed of the main steel structure beam column 1 and the main structure side steel plate 2 . The soil layer conditions of the slope model 27 can be prepared according to test requirements, such as homogeneous silt slopes, multi-layer soil slopes, and the like. The filling method of the slope model can be the sand rain method, or it can be compacted with a certain density by a tamping machine after filling. During the filling process of the slope model 27, monitoring instruments such as earth pressure sensors 25, pore water pressure sensors 26, and water content probes are buried in several positions inside the slope, and the data lines of the buried instruments are drawn out from the data line lead-out hole 4; After completion, arrange displacement sensors 24 and inclinometers at several positions on the slope surface and the top of the slope, and insert the tensiometer into the slope model through the instrument embedding hole 3 arranged on the side steel plate 2 of the main structure.

After the slope filling is completed, start the water level control system, use the hand chain hoist 9 to gradually increase the water level of the constant head water tank 7, and open the first control valve 12 and the second control valve 12 to continuously increase the water level in the slope model. high until the desired water table is reached within the slope model.

The pressure bearing plate 21 and the hydraulic jack 20 are arranged in the designated area on the top surface of the slope model 27, and the required load is applied to the slope model through the hydraulic control system until the slope model becomes unstable and landslides. During the loading process, the embedded sensors and data acquisition system are used to monitor the stress field and deformation field of the slope model in real time, and at the same time, the lateral deformation of the soil and the position of the sliding surface can be directly observed through the side visible window 5 .

The above-mentioned specific embodiments are used to explain the utility model, rather than to limit the utility model. Within the spirit of the utility model and the scope of protection of the claims, any modifications and changes made to the utility model fall into the scope of the utility model. scope of protection.

Claims (2)

1. ground and slope engineering model test platform, it is characterized in that: comprise the rectangular bar of steel structural model groove that main body beam column of steel structure (1) and agent structure side steel plate (2) are formed, row, every row have a plurality of instrument embeddings hole (3) and data extension line hole (4) more than vertically being provided with side by side on one side, long limit of agent structure side steel plate (2), and row, every row have a plurality of visual windows (5) more than vertically being provided with on the another side, long limit of agent structure side steel plate (2); In the rubble of rectangular bar of steel structural model trench bottom and sand bedding course (16), be provided with the branch road water pipe pipe networks (15) that many rows take the water hole out of, after the branch road water pipe pipe network (15) of taking the water hole out of is interconnected, through several respectively with the water pipe of first by-pass valve control (12) be divided into two-way after hard water pipe (14) is communicated with, one the tunnel behind second by-pass valve control (12) water receiving case (7), connect vacuum water plug (6) behind another Lu Jingdi three by-pass valve controls (12) and the 4th by-pass valve control (12); Minor face one side of agent structure side steel plate (2) is provided with osculum (17); Go up face length limit both sides cross-over connection reaction beam (18) at main body beam column of steel structure (1), reaction beam (18) two ends have buckle (19) respectively, reaction beam (18) is strained and fixed with buckle (19) after sliding along long limit, reaction beam (18) lower surface is provided with several the hydraulic jack (20) by hydraulic control system (29) control, the servo loading system that several lifting jack (20) sliding end uses globular hinge (22) and bearing plate (21) to connect to form respectively; Go up face length limit both sides cross-over connection displacement transducer movable supporting frame (23) at main body beam column of steel structure (1), displacement transducer movable supporting frame (23) below is provided with several displacement transducers (24), and displacement transducer movable supporting frame (23), displacement transducer (24), soil pressure sensor (25) and pore water pressure sensor (26) etc. connect to form monitoring system.

2. a kind of ground according to claim 1 and slope engineering model test platform, it is characterized in that: described water tank (7) hangs on the sliding rail of the lifting support (11) of being with chain block (9), is provided with in the water tank (7) to keep the constant constant head ball-cock assembly (8) of water level.

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