CN103759702A - Testing system for base layer sedimentation model of immersed tube tunnel and operation method of testing system - Google Patents

Abstract

The invention discloses a subsidence model test system and an operation method thereof for an immersed tube tunnel foundation layer, wherein the test system includes: a model water tank, a pipe joint model, a gantry crane, a measuring frame, a dial indicator, a sand injection machine, a water stop valve, Sand injection pipes, pads and jacks, the pads are distributed at the bottom of the model water tank, the jack is set on the pads, the pipe joint model is placed on the jack, the gantry crane and the measuring frame are set above the model water tank, and the dial indicator is fixed on the measurement On the shelf, the measuring head of the dial indicator is placed on the pipe joint model. There is a sand injection hole on the pipe joint model. The sand injection hole is connected to the water stop valve. There is a valve on the sand injection pipe. water valve. Compared with the prior art, the present invention has the following advantages and effects: the structure is simple, and the model test of the settlement of the base layer of the immersed tube tunnel can be completed; by injecting different sand and water, the influence of sand and water on the settlement can be tested; Back to the sedimentation solution, you can test the influence of the backsilting layer on the settlement.

Description

A settlement model test system and its operation method for the foundation layer of immersed tube tunnel

technical field

The invention relates to a structural model test system, in particular to a subsidence model test system of an immersed tube tunnel base layer and an operation method thereof. the

Background technique

In the process of laying underwater tunnels, the usual method is to first let the box body of the main immersed tube section be accurately placed in the pre-excavated foundation groove, and then use the sand filling method to reinforce the foundation of the immersed tube section. This method is suitable for Slipway type pipe section with small bottom width. Due to the development of technology, the model test research on the sand filling method has also made great progress. Among them, the research on the expansion law of the sand tray and the related parameters of the sand filling and the research on the influence of the sand material ratio on the sand filling are very mature. The influence of different working conditions has also been considered in the relevant model tests, and related conclusions have been drawn. Many studies have basically affirmed the effectiveness and feasibility of the sand filling method, which provides valuable information for the actual engineering design and construction application. Reference and basis. However, in the existing model tests related to the sand filling method, there is no research on the settlement of the immersed tube tunnel. Due to the lack of scientific experimental reference and support for the settlement factors of immersed tunnels, the settlement size cannot be accurately determined in the current design of immersed tunnels. During construction, it is often necessary to predict the pipe joints within an estimated range. It cannot meet the application requirements of the increasingly advanced immersed tube tunnel. the

Contents of the invention

The purpose of the present invention is to overcome the above-mentioned deficiencies in the prior art, and to provide a subsidence model test system and its operation method for the subsidence of the base layer of the immersed tube tunnel, which has a reasonable structure design and can test the influence of environmental parameters and construction parameters on the subsidence. the

The technical scheme adopted by the present invention to solve the above-mentioned problems is: the subsidence model test system of the immersed tunnel tunnel, which is characterized in that it includes: a model water tank, a pipe joint model, a gantry crane, a measuring frame, a dial indicator, a sand injection machine, a stop Water valves, sand injection pipes, pads and jacks, where the pads are distributed at the bottom of the model water tank, the jack is set on the pads, the pipe joint model is placed on the jack, the gantry crane and the measuring frame are set above the model water tank, and the dial indicator Fixed on the measuring frame, the measuring head of the dial indicator is placed on the pipe joint model, and there is a sand injection hole on the pipe joint model. pipe to the water stop valve.

The model water tank of the present invention is connected with a circulating water tank, the circulating water tank is connected with a water pump, and the water pump is connected with a sand injection machine. The water in the model water tank will flow to the circulating water tank, and the excess water will be pumped out from the circulating water tank by the water pump and put back into the sand injection machine;

The operating method of the base layer settlement model test system of the immersed tube tunnel of the present invention is characterized in that it comprises the following steps:

1) Lay a gravel layer on the bottom of the model tank, clean up the gravel at the four corners of the bottom of the model tank, and place pads;

2) Evenly sprinkle the back-silting solution on the surface of the gravel layer to form a back-silting layer on the surface of the gravel layer;

3) Place a jack on the block;

4) Use the gantry crane to hang the pipe joint model on the jack;

5) Use a jack to jack up the pipe joint model, and close all the water stop valves;

6) Cover the pipe joint model with gravel to form an approximately closed space at the bottom of the pipe joint model;

7) Fill water into the model water tank, and stop watering when the water level exceeds the bottom of the pipe joint model;

8) The sand injection pipe is connected to one of the water stop valves, and the valve of the sand injection pipe and the water stop valve are opened;

9) Open the self-circulation valve of the sand injection machine, perform self-circulation first, and pour a certain proportion of water and sand into the sand injection machine during this period;

10) Close the self-circulation valve of the sand injection machine to inject sand;

11) After sand injection for a period of time, excavate gravel around the pipe joint model and near the water stop valve to form an observation hole;

12) When the sand overflows the observation hole, first open the self-circulation valve of the sand injection machine, then close the valve and water stop valve of the sand injection pipe, and the sand injection machine starts self-circulation;

13) Remove the sand injection pipe from the water stop valve and connect it to the water stop valve of the next sand injection hole;

14) Repeat steps 9-13 above until all sand injection holes are filled;

15) After the sand injection is completed, clean the sand injection pipe and turn off the power of the sand injection machine;

16) Adjust the dial indicator to vertical, check whether each dial indicator is normal, and record the initial reading of the dial indicator at this time;

17) Use the gantry crane to lift the pipe joint model and take out the jack;

18) The gantry crane places the pipe joint model on the perfusion sand cushion and unloads the force;

19) According to the relationship between the load to be added and the amount of water put in, water is released to the pipe joint model, so that the perfusion sand cushion is loaded to a certain load;

20) Collect dial gauge readings;

21) Repeat the above steps 19 and 20 until the final load is loaded.

Preferably, the following steps are used for collecting the dial indicator reading data described in step 19: reading every 5 minutes for the first 15 minutes, and reading every 15 minutes after 15 minutes until the reading of the dial indicator remains unchanged. the

Preferably, the final load is 2.5kPa-4kPa. the

Compared with the prior art, the present invention has the following advantages and effects:

1) The structure is simple, and the model test of the settlement of the base layer of the immersed tunnel can be completed;

2) By injecting different sand water, the effect of sand water on settlement can be tested;

3) By sprinkling the back-silting solution with different concentrations, the influence of the back-silting layer on the settlement can be tested.

Description of drawings

Fig. 1 is the structural representation of the embodiment of the present invention;

Fig. 2 is the partial structure schematic diagram of the embodiment of the present invention;

Fig. 3 is a schematic diagram of the position of the measuring point of the dial gauge according to the embodiment of the present invention.

Detailed ways

The present invention will be further described in detail below in conjunction with the accompanying drawings and examples. The following examples are explanations of the present invention and the present invention is not limited to the following examples. the

Referring to Fig. 1-Fig. 2, the subsidence model test system of the immersed tube tunnel base layer in this embodiment includes: model water tank 1, pipe joint model 2, gantry crane, measuring frame 4, dial indicator 5, sand injection machine 6, water stop Valve 7, sand injection pipe 8, cushion block 9 and jack 3, wherein cushion block 9 is distributed at the bottom of model water tank 1, jack 3 is set on cushion block 9, pipe joint model 2 is placed on jack 3, gantry crane and measuring frame 4 Set above the model water tank 1, the dial gauge 5 is fixed on the measuring frame 4, the measuring head of the dial gauge 5 is placed on the pipe joint model 2, and a sand injection hole is opened on the pipe joint model 2, and the sand injection hole is connected to the water stop The valve 7 and the sand injection pipe 8 are provided with valves, and the sand injection machine 6 is connected to the water stop valve 7 through the sand injection pipe 8 . The model water tank 1 is connected with a circulating water tank 10, and the circulating water tank 10 is connected with a water pump 11, and the water pump 11 is connected with the sand injection machine 6. the

The operation method of the subsidence model test system for the base layer of the immersed tunnel in this embodiment includes the following steps

1) Lay the gravel layer 12 on the bottom of the model water tank 1, clean up the gravel at the four corners on the bottom of the model water tank 1, and place cushion blocks 9;

2) Evenly sprinkle the back-silting solution on the surface of the gravel layer 12 to form a back-silting layer on the surface of the gravel layer 12;

3) Place the jack 3 on the block 9;

4) Hang the pipe joint model 2 on the jack 3 with a gantry crane;

5) Use the jack 3 to jack up the pipe joint model 2, and close all the water stop valves 7;

6) Cover the pipe joint model 2 with gravel, so that the bottom of the pipe joint model 2 forms an approximately closed space;

7) Fill water into the model water tank 1, and stop watering when the water level exceeds the bottom of the pipe joint model 2;

8) The sand injection pipe 8 is connected to one of the water stop valves 7, and the valve of the sand injection pipe 8 and the water stop valve 7 are opened;

9) Open the self-circulation valve of the sand injection machine 6, perform self-circulation first, and pour a certain proportion of water and sand into the sand injection machine 6 during this period;

10) Close the self-circulation valve of sand injection machine 6 to inject sand;

11) After sand injection for a period of time, excavate gravel around the pipe joint model 2 and near the water stop valve 7 to form an observation hole;

12) When the sand overflows the observation hole, first open the self-circulation valve of the sand injection machine 6, then close the valve of the sand injection pipe 8 and the water stop valve 7, and the sand injection machine 6 starts self-circulation;

13) Remove the sand injection pipe 8 from the water stop valve 7 and connect it to the water stop valve 7 of the next sand injection hole;

14) Repeat steps 9-13 above until all sand injection holes are filled with sand;

15) After the sand injection is completed, clean the sand injection pipe 8 and turn off the power of the sand injection machine 6;

16) Adjust the dial indicator 5 to vertical, check whether each dial indicator 5 is normal, and record the initial reading of the dial indicator 5 at this time;

17) Use the gantry crane to lift the pipe joint model 2, and take out the jack 3;

18) The gantry crane places the pipe joint model 2 on the perfusion sand cushion layer 13 and unloads the force;

19) According to the relationship between the load to be added and the amount of water put in, water is released to the pipe joint model 2, so that the perfusion sand cushion layer 13 is loaded to a certain load, and the reading of the dial gauge 5 at this time is recorded;

20) For the first 15 minutes, read every 5 minutes, and then read every 15 minutes after 15 minutes until the reading of dial indicator 5 remains unchanged; the position of dial indicator 5 is shown in the circle position in Figure 3. In this embodiment, there are a total of 11 dial gauges with 5 measuring points.

21) Repeat steps 19 and 20 above until the final load is loaded. The final load is set between 2.5kPa-4kPa. the

The above content described in this specification is only an illustration of the present invention. Those skilled in the technical field to which the present invention belongs can make various modifications or supplements to the described specific embodiments or adopt similar methods to replace them, as long as they do not deviate from the content of the description of the present invention or exceed the scope defined in the claims , should belong to the protection scope of the present invention. the

Claims (5)

1. an immersed tube tunnel basal layer deformation model test system, it is characterized in that, comprise: model water tank (1), tube coupling model (2), transfer gantry, measurement bay (4), dial gauge (5), sand filler (6), water check valve (7), note sandpipe (8), cushion block (9) and lifting jack (3), wherein cushion block (9) is distributed in model water tank (1) bottom, lifting jack (3) is arranged on cushion block (9), tube coupling model (2) is placed on lifting jack (3), transfer gantry and measurement bay (4) are arranged on the top of model water tank (1), dial gauge (5) is fixed on measurement bay (4), the measuring head of dial gauge (5) withstands on tube coupling model (2), tube coupling model offers note sand hole on (2), note sand hole connects water check valve (7), on note sandpipe (8), be provided with valve, sand filler (6) connects water check valve (7) by note sandpipe (8).

2. immersed tube tunnel basal layer deformation model test system according to claim 1, it is characterized in that: described model water tank (1) is connected with cyclic water tank (10), cyclic water tank (10) is connected with water pump (11), and water pump (11) is connected with sand filler (6).

3. a method of operating for immersed tube tunnel basal layer deformation model test system claimed in claim 1, is characterized in that, comprises the following steps:

In model water tank (1) bottom, spread metalling (12), the rubble in upper four corners, cleaning model water tank (1) bottom, and place cushion block (9);

At metalling (12) surface uniform, spill the solution that back-silts, make the layer that back-silts of formation on metalling (12) surface;

On cushion block (9), place lifting jack (3);

With transfer gantry, tube coupling model (2) is hung to lifting jack (3);

With lifting jack (3) jack-up tube coupling model (2), close whole water check valves (7);

At tube coupling model (2), use gravel mulch around, make tube coupling model (2) bottom form the space of an approximate sealing;

In model water tank (1), pour water, when water level surpasses tube coupling model (2) bottom, stop pouring water;

Note sandpipe (8) connects one of them water check valve (7), opens valve and the water check valve (7) of note sandpipe (8);

Open the valve of sand filler (6) self-loopa, first carry out self-loopa, and in sand filler (6), pour a certain proportion of water and sand in the meantime;

Close the valve of sand filler (6) self-loopa, note sand;

Wait noting sand after a period of time, at tube coupling model (2) around and excavate rubble near the position of water check valve (7) and form viewport;

Treat that sand overflows viewport, first open the valve of sand filler (6) self-loopa, then close valve and the water check valve (7) of note sandpipe (8), sand filler (6) starts self-loopa;

To note sandpipe (8) and unload from water check valve (7), be connected with the water check valve (7) of next one note sand hole;

Repeat above-described step 9-13, until it is complete all to note sand hole note sand;

After note sand, clean note sandpipe (8), the power supply of closing sand filler (6);

Adjust dial gauge (5) to vertical, check that whether each dial gauge (5) is normal, record the now initial reading of dial gauge (5);

Utilize transfer gantry that tube coupling model (2) is sling, take out lifting jack (3);

Transfer gantry is placed on perfusion sand bedding course (13) by tube coupling model (2) and goes up and unload power;

According to the load that should add and the relation of putting into the water yield, the tube coupling model (2) that discharges water, makes to pour into sand bedding course (13) and is loaded on a constant load;

Gather dial gauge (5) readings;

Repeat above step 19,20, until be loaded on final load.

4. method of operating according to claim 3, is characterized in that: collection dial gauge (5) readings described in step 20 adopts following steps: first 15 minutes, every 5 minutes readings, after 15 minutes every 15 minutes readings, until dial gauge 5 readings are constant.

5. method of operating according to claim 3, is characterized in that: described final load is 2.5kPa-4kPa.

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