[0048] Example one
[0049] Shield tunnel external water pressure monitoring device, such as Figure 1~3 As shown, it includes a pre-embedded casing 1, a water inlet filter pipe 2, a water cutoff device 3, and a piezometer monitoring assembly 4. The water inlet filter pipe 2 is telescopically arranged in the pre-embedded casing 1, and a water cutoff device 3 is installed at the end of the water inlet filter pipe 2, the osmometer monitoring component 4 is connected with the water interception device 3, and is installed in the embedded casing 1.
[0050] When the water inlet filter tube 2 penetrates the grouting layer, the water from the grouting layer flows into the water inlet filter tube 2. After the grouting, the water quality has a higher calcium content. Although the sensor is equipped with permeable stones, the permeable stones can prevent stones The silt and other substances block the sensor, but the water containing calcification is easy to adhere to the permeable stone. After a period of time, the sensor is blocked, making the sensor invalid and unable to measure normally. Therefore, this embodiment adopts a water cutoff device 3, which can reduce the calcium content of the grouting layer slurry, and then use the osmometer monitoring component 4 to top off the water cutoff device 3 for water pressure monitoring, thereby avoiding the above problems. .
[0051] Such as Figure 4 As shown, the top of the pre-embedded casing 1 is provided with a socket hole 11, the socket hole 11 is provided with an internal thread, and the water inlet filter tube 2 is threadedly connected with the socket hole 11, thereby realizing water inlet filtration The extension and receipt of the pipe 2 in the embedded casing 1. An accommodating cavity 12 is provided inside the pre-embedded casing 1, and the pipe body of the water inlet filter tube 2 is arranged in the accommodating cavity 12.
[0052] Such as Figure 5 As shown, the top of the water inlet filter tube 2 is provided with a sealing head 21, which can seal the top of the embedded casing 1 when the water inlet filter tube 2 is completely received in the embedded casing 1, thereby Prevent the slurry and other substances from entering the embedded casing 1 during grouting.
[0053] Further, the pipe body of the water inlet filter pipe 2 is provided with a plurality of grooves 23, and the purpose of the grooves 23 is to easily screw the pipe body of the water inlet filter pipe 2 and the geotextile can be installed at the same time. For the filtering function, correspondingly, each groove 23 is provided with at least one water inlet hole 22 inside, and the water inlet hole 22 is used to make the external water flow into the water inlet filter tube 2.
[0054] Such as Image 6 As shown, the water interception device 3 includes a valve set 37 and an outer sleeve 38. The upper and lower ends of the valve set 37 are provided with connecting holes. The connecting holes include an upper connecting hole 361 and a lower connecting hole 362. The upper connecting hole 361 is used to connect with the end of the water inlet filter tube 2. Specifically, the connection manner between the upper connection hole 361 and the water inlet filter tube 2 may be threaded connection. The lower connecting hole 362 is used to connect with the outer sleeve 38. Specifically, the connecting manner between the lower connecting hole 362 and the outer sleeve 38 may also be a threaded connection. The valve assembly 37 is further provided with a limiting block 34, a resetting piece 33, a stop valve 32, and an annular convex ring 35 from top to bottom. The stop valve 32 is connected to the limiting block 34 through the resetting piece 33. The stop valve 32 can be moved upward under the action of external force, thereby opening the valve port, so that the water hole 31 is opened, and the stop valve 32 compresses the reset member 33; when the external force is removed, under the elastic recovery of the reset member 33, the stop valve 32 Under the action of the resetting member 33, it moves downwards until it squeezes the annular convex ring 35, thereby closing the valve port and closing the water passage hole 31.
[0055] Such as Figure 7 As shown, the piezometer monitoring assembly 4 includes an inner sleeve 43 and a water pressure sensor 5, and the inner sleeve 43 is connected to the outer sleeve 38, preferably in a threaded connection. The water pressure sensor 5 is arranged in the inner sleeve 43, and a plurality of first water inlets 431 are provided on both sides of the inner sleeve 43. A top valve 41 is provided on the top of the water pressure sensor 5, and the top valve 41 There are second water inlets 432 on both sides. In use, during the threaded connection of the inner sleeve 43 and the outer sleeve 38, the top valve member 41 can gradually push up the stop valve 32, so that the water flow can enter the piezometer monitoring assembly 4.
[0056] When the water pressure sensor 5 is not installed, the external water is not connected. After the embedded casing 1 and the water inlet filter pipe 2 are installed successfully, the water pressure sensor 5 is installed to avoid the damage of the pipe slices during the transportation and construction. Damage, causing unnecessary losses, and at the same time, it can also achieve a safer replacement of the sensor, because the sensor can automatically stop water after being taken out.
[0057] After all, the service life of the water pressure sensor 5 is limited. When it is damaged, it can not only be removed and replaced, but also in the process of removal, the top valve 41 is also screwed out, so that the water interception device 3 is closed and the water No leakage, so the safety of the replacement process is guaranteed.
[0058] The bottom of the inner sleeve 43 is also provided with a sealing gland 44, which is threadedly connected to the inner sleeve 43, and the sealing gland 44 is also provided with an outlet hole 45, which can be used for sensors The cable sticks out.
[0059] The connection between the water inlet filter pipe 2 and the embedded casing 1 is also provided with a rubber ring. When pre-embedded, the rubber ring can ensure that the concrete does not penetrate into the thread of the connection, and can prevent the grout from entering the thread of the connection during grouting. To ensure that the device can work normally.
[0060] The top of the water inlet filter pipe 2 is a conical plug. The conical plug is easily pushed to the periphery of the pipe segment to pass through the grouting layer. During grouting, the grout can be prevented from entering the thread, so that the device can work normally.
[0061] The length of the water inlet filter pipe 2 is long enough to pass through the grouting layer, so that the external water pressure can be measured more accurately.
[0062] The installation and monitoring methods of the above-mentioned shield tunnel external water pressure monitoring device are as follows:
[0063] Before the production of the tube segments, plug both ends of the embedded casing 1 with stainless steel protective caps to prevent the concrete from entering the embedded casing 1 and destroy the internal thread structure of the casing, and stainless steel protective covers at both ends Adhere a foam with good elasticity to the plug, and use the foam to hold one or both ends of the template, so that it is convenient to find the protective cover plug after the template is disassembled; put the embedded casing 1 into the prepared template and fix it After the pouring is completed and the curing is complete, clean the protective cover plugs at both ends of the embedded casing 1 to check whether the inside of the embedded casing 1 is unblocked; then lubricate the outer arc surface end of the embedded casing 1 Oil, screw the water inlet filter tube 2 pre-wrapped with geotextile into the embedded casing 1 from the outer arc surface, and seal it (convenient for transportation and installation, and prevent the slurry from entering the casing during grouting to affect the use effect) ; After the segment splicing is completed and the grouting is completed, wait 6-12 hours until the slurry is stable, and then insert the water cutoff device 3 from the inner arc surface and connect it to the water inlet filter pipe 2. After the connection is completed, wait a few minutes, and continue to screw in , Until it is screwed to the preset position; the water inlet filter pipe 2 passes through the grouting layer to reach the rock and soil layer, so that the outside water can enter the water inlet filter pipe 2, at this time the water interception device 3 is closed, completely blocking the outside After the slurry becomes more stable, screw the piezometer monitoring assembly 4 into the outer sleeve 38 from the inner arc surface. During the screwing process, the top valve 41 pushes the stop valve 32 and enters the inlet filter pipe 2 The water flows into the outer sleeve 38 and the inner sleeve 43 through the shut-off valve 32, and contacts the water pressure sensor 5 (osmometer), and then screw a protective cover with a sealing gland at the bottom of the embedded sleeve, and Tighten the gland and perform a second seal to ensure no water leakage. After the water pressure is stable, the external water pressure can be measured.
