A prestressed support rod and supporting frame for supporting open-cut tunnel foundation pits

Abstract

This invention discloses a prestressed support rod and a three-dimensional support frame for supporting open-cut tunnel foundation pits, belonging to the field of civil engineering technology. The support rod includes a support part, a limiting part, a first connecting pipe, a second connecting pipe, an air inlet one-way valve, and a first wireless air pressure sensor. The first wireless air pressure sensor in the sliding groove can monitor the pressure change in the chamber in real time, indirectly reflecting the prestress loss. It eliminates the need for daily manual inspection, saving more than 80% of the labor cost of inspection. Moreover, the sensor can accurately locate the faulty support rod and its specific end position, transforming comprehensive investigation into precise maintenance, shortening the fault response time from the traditional 24 hours to 1-2 hours, and avoiding the risk of foundation pit collapse caused by prestress instability. The pressure-resistant part, in conjunction with the return spring, can indirectly monitor deformation through pressure changes in the sliding groove, and can also directly detect pressure fluctuations in the connecting channel through the second wireless air pressure sensor, forming a dual monitoring mechanism that can promptly detect minor deformations of the inner wall of the foundation pit.

Description

Technical Field

[0001] This invention belongs to the field of civil engineering technology, specifically, it relates to a prestressed support rod and a three-dimensional support frame for supporting the foundation pit of an open-cut tunnel. Background Technology

[0002] Prestressed foundation pit support is a foundation pit support system that actively applies prestress to enable the support structure to resist soil and water pressure before the foundation pit is excavated. It can effectively control foundation pit deformation and protect the surrounding environment (such as buildings and underground pipelines). It is widely used in soft soil areas, deep foundation pits (usually with an excavation depth of ≥10m), or projects with sensitive surrounding environments. Its core logic is "controlling deformation with force", which is different from traditional passive support.

[0003] During construction, brackets and anchors are pre-installed on the foundation pit retaining structure (such as diaphragm wall), and supporting components (such as steel supports and anchor cables) are installed. The design value of preload or pretension is slowly applied to the supporting components through hydraulic jacks, tensioning equipment, etc. After the preload reaches the design value, the supporting components are locked with anchors, bolts, etc. to keep them in the preloaded state.

[0004] The essence of prestressed bracing is to apply pretension or preload to the supporting components (such as steel strands, steel sections, and steel pipes) to generate reverse internal forces in advance, thereby counteracting the active earth pressure and water pressure released by the soil during the excavation of the foundation pit, and thus limiting the displacement of the retaining structure (such as diaphragm walls and piles).

[0005] Chinese invention patent CN111622235A discloses a prestressed support rod for foundation pit retaining, including a support base, a telescopic base, a support pipe, a connecting flange, wedges, and jacks. This invention decomposes the prestressed support rod into basic components: a support base, a telescopic base, a support pipe, and a connecting flange. These basic components are easily combined to form a telescopic pipe, an intermediate connecting pipe, and an anchor connecting pipe. The support base is combined with the telescopic pipe, along with wedges and jacks, to form the prestressing application section of the support rod. The telescopic pipe is combined with one or more intermediate connecting pipes to form the length adjustment section of the support rod. The intermediate connecting pipe is combined with the anchor connecting pipe to form the anchor section, which is inserted below the bottom of the foundation pit and reinforced by grouting.

[0006] While the support rod can correct deformation of the foundation pit retaining structure, after the hydraulic jacks or tensioning equipment drive the support to apply the designed preload and fix it in place, the rod and the retaining structure bracket are prone to deformation due to stress over time, resulting in gaps. These gaps can cause the preload to be lost shortly after construction, and there is currently a lack of real-time monitoring methods to keep track of changes in preload. Furthermore, daily on-site inspections by manual labor are required, including checking the locking status of the jacks, measuring the rod's axial deviation, and randomly checking axial force using portable equipment. Each inspection requires 2-3 people and takes 1-2 hours per foundation pit. Manual inspection is also prone to randomness and low accuracy, significantly increasing labor costs. Summary of the Invention

[0007] The purpose of this section is to outline some aspects of embodiments of the present invention and to briefly describe some preferred embodiments. Simplifications or omissions may be made in this section, as well as in the abstract and title of this application, to avoid obscuring the purpose of these documents; however, such simplifications or omissions should not be construed as limiting the scope of the invention.

[0008] To address the issues raised in the background art, where, after applying the designed preload to the support using hydraulic jacks or tensioning equipment and fixing it in place, the rod and the retaining structure's corbel are prone to deformation over time due to stress, leading to gaps. These gaps cause a loss of preload shortly after construction, and currently, there is a lack of real-time monitoring methods to promptly grasp changes in preload. Furthermore, daily on-site inspections by manual labor are necessary, including checking the jack locking status, measuring rod axis deviation, and randomly checking axial force using portable equipment. Each inspection requires 2-3 people and takes 1-2 hours per pit. Manual inspection also suffers from high randomness and low accuracy, significantly increasing labor costs. Therefore, this invention adopts the following technical solution.

[0009] A prestressed support rod for supporting open-cut tunnel foundation pits includes multiple support sections, each with a connecting flange. The connecting flanges of adjacent support sections are abutted and fixed by a first fixing bolt. Each support section has an outwardly extending pressure-applying section at both ends. Each connecting flange is fixedly connected to multiple support inclined plates near the outer wall of the support section. The ends of the support sections on both sides of the support rod are telescopically connected to movable sections, the ends of which are fixedly connected to the outer wall of the pressure-applying sections. The ends of the support sections on both sides of the support rod are provided with sliding grooves. The ends of the movable sections inserted into the sliding grooves are fixedly connected to limiters. The inner side of the sliding grooves is provided with a first connecting pipe and a second connecting pipe. The outer wall of the support section is detachably connected to an air inlet check valve and a first wireless air pressure sensor. The air inlet check valve communicates with the first connecting pipe, and the first wireless air pressure sensor communicates with the second connecting pipe. A first inclined plate is rotatably connected to the bottom inner side of the sliding groove by a torsion spring. A second inclined plate is provided at the raised end of the first inclined plate, and a rubber section is provided between the second inclined plate and the first inclined plate.

[0010] Preferably, the support part has detachable mounting brackets on both sides of its end, the hydraulic jack is mounted on the outer wall of the mounting bracket and the telescopic end contacts the pressure part, and multiple fixing wedges are inserted into the interior of the moving part.

[0011] Preferably, the moving part is provided with a limiting groove, and the inner wall of the sliding groove is provided with a sliding protrusion, and the limiting groove and the sliding protrusion are inserted into each other.

[0012] Preferably, the outer wall of the movable part is fitted with a plurality of left and right opposite C-shaped frames, and a protrusion is fixedly connected to the upper end of each C-shaped frame. The second fixing bolt passes through the fixing wedge and the protrusions on both sides.

[0013] Preferably, a detection component is provided at the end of the pressure application part, which can detect the condition of the inner wall of the pit.

[0014] Preferably, the detection component includes a pressing part, the end of which is provided with a connecting channel communicating with a sliding groove, a mounting bracket is fixedly connected inside the connecting channel, a return spring is provided on the mounting bracket, and a sliding rod is slidably connected inside the connecting channel, the sliding rod being fixedly connected to the pressing part.

[0015] Preferably, the detection component includes a pressing part, the end of the pressing part is provided with a connecting channel, a mounting bracket is fixedly connected inside the connecting channel, a return spring is provided on the mounting bracket, a sliding rod is slidably connected inside the connecting channel, the sliding rod is fixedly connected to the pressing part, and a second wireless air pressure sensor is detachably connected to the outer wall of the pressing part, the detection end of the second wireless air pressure sensor is connected to the inside of the connecting channel.

[0016] Preferably, a rotating shaft is fixedly connected to the outer wall of the connecting flange, and a limiting turntable is fixedly connected to the end of the rotating shaft. The rotating shaft is inserted into the end of the support, and the limiting turntable is embedded inside the support.

[0017] The present invention also discloses a three-dimensional support frame for foundation pit support, which is equipped with the above-mentioned support rod. The three-dimensional support frame includes a support channel steel set at the bottom of the support part. Support vertical piles are detachably connected to both sides of the outer wall of the support channel steel. A fixing clamp is set on the support channel steel to fix the support part above the support channel steel.

[0018] Preferably, the two ends of the fixing clamp are fixedly connected to connecting parts, the inside of the supporting channel steel is inserted with a fixing part, the outer wall of the fixing part near the bottom is provided with an insertion groove, the insertion groove is engaged with the protrusion near the bottom of the supporting channel steel, the bottom of the fixing part is threadedly connected with a fastening bolt, the supporting channel steel is provided with a threaded hole, the threaded end of the fastening bolt is threadedly connected to the supporting channel steel, the fixing part is rotatably connected with a double-ended screw, the two outer walls of the fixing part are threadedly connected with sliding parts, the sliding parts are inserted into the inside of the supporting channel steel, the two ends of the double-ended screw are fixedly connected with hexagonal heads, the outer wall of the sliding part is threadedly connected with a rotating pin, the rotating pin connects the connecting part with the outer wall of the sliding part, and the connecting part can rotate along the axis of the rotating pin.

[0019] Compared with the prior art, the beneficial effects of the present invention are as follows:

[0020] 1. The first wireless air pressure sensor in the sliding groove can monitor the pressure change in the chamber in real time, indirectly reflecting the pre-pressure loss. It eliminates the need for daily manual inspection, saving more than 80% of the labor cost of inspection. Moreover, the sensor can accurately locate the faulty support rod and its specific end position, transforming the comprehensive investigation into precise maintenance. This reduces the fault response time from the traditional 24 hours to 1-2 hours, avoiding the risk of pit collapse caused by pre-pressure instability.

[0021] 2. The pressure-retaining part, in conjunction with the reset spring, can indirectly monitor deformation through changes in the pressure of the sliding groove, and can also directly detect pressure fluctuations in the connecting channel through the second wireless air pressure sensor, forming a dual monitoring mechanism. The monitoring accuracy is improved to ±0.5kPa, which can promptly detect minute deformations of the pit wall and provide data support for the safety protection of surrounding buildings and underground pipelines.

[0022] 3. The support piles and support channel steel work together to suspend the support rod inside the foundation pit, avoiding uneven stress caused by the support rod contacting the soil at the bottom of the foundation pit; at the same time, the fixing clamp is driven by the sliding part through the bidirectional screw to tighten synchronously, which increases the contact area between the clamp and the support part by more than 60% and the fixing force by 50%, effectively preventing the support rod from shifting in the horizontal direction.

[0023] 4. The fixing part engages with the protrusion of the support channel steel through the insertion groove, and is locked by the thread of the bottom fixing bolt. The fixing position can be quickly adjusted, and the adjustment time is shortened to less than 15 minutes, which can adapt to the installation needs of support rods of different heights. Moreover, compared with traditional welding fixing, the threaded connection can avoid the deformation of the support channel steel caused by welding stress, and improve the reuse rate of the three-dimensional frame from the traditional 60% to more than 90%. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention;

[0025] Figure 2 This is a front view schematic diagram of the support rod structure in this invention;

[0026] Figure 3 This is a schematic diagram of the support structure in this invention;

[0027] Figure 4 In this invention Figure 3 Enlarged structural diagram at point A in the middle;

[0028] Figure 5 This is a schematic cross-sectional view of the support portion in this invention;

[0029] Figure 6 This is a schematic cross-sectional view of the support portion in this invention;

[0030] Figure 7 This is a schematic diagram of the connection structure between the pressure application part and the support part in this invention;

[0031] Figure 8 This is a schematic diagram of the voltage equalization component structure in this invention;

[0032] Figure 9 This is a schematic diagram of a prestressed support frame structure for foundation pit support according to the present invention;

[0033] Figure 10 This is a schematic diagram of the fixed component structure in this invention;

[0034] Figure 11 This is a schematic cross-sectional view of the support portion in this invention;

[0035] Figure 12 This is a schematic diagram of the detection component structure according to another preferred embodiment of the present invention;

[0036] Figure 13 In this invention Figure 12 Enlarged structural diagram at point B.

[0037] The correspondence between the labels and component names in the attached figures is as follows:

[0038] 100. Support part; 101. Connecting flange; 102. Supporting inclined plate; 103. First fixing bolt; 104. Assembly bracket; 105. First connecting pipe; 106. Sliding groove; 107. Second connecting pipe; 108. Rotating shaft; 109. Limiting turntable; 110. Sliding protrusion;

[0039] 200. Pressing part; 201. Moving part; 202. Limiting groove; 203. Fixing wedge; 204. Second fixing bolt; 205. Inlet one-way valve; 206. First wireless air pressure sensor; 207. Limiting part; 208. C-shaped frame; 209. Protrusion; 210. First inclined plate; 211. Second inclined plate; 212. Rubber part; 213. Pressure sensor; 214. Sliding block; 215. Pressing block; 216. Telescopic rod; 217. Pressing head; 218. Buffer spring; 219. Telescopic plate;

[0040] 300, Pressing part; 301, Sliding rod; 302, Return spring; 303, Mounting bracket; 304, Second wireless barometric pressure sensor; 305, Connecting channel;

[0041] 400. Supporting vertical pile; 401. Supporting channel steel; 402. Fixing clamp; 403. Connecting part; 404. Sliding part; 405. Double-acting screw; 406. Fixing part; 407. Fastening bolt; 408. Insertion groove; 409. Rotating pin. Detailed Implementation

[0042] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0043] Many specific details are set forth in the following description in order to provide a full understanding of the invention. However, the invention may also be practiced in other ways different from those described herein, and those skilled in the art can make similar extensions without departing from the spirit of the invention. Therefore, the invention is not limited to the specific embodiments disclosed below.

[0044] Secondly, the term "one embodiment" or "embodiment" as used herein refers to a specific feature, structure, or characteristic that may be included in at least one implementation of the present invention. The phrase "in one embodiment" appearing in different places throughout this specification does not necessarily refer to the same embodiment, nor is it a single or selective embodiment that mutually excludes other embodiments. The present invention provides the following embodiments.

[0045] Example 1: As Figure 1 as well as Figure 2The diagram shows a prestressed support rod structure for supporting open-cut tunnel foundation pits according to a preferred embodiment of the present invention. This embodiment of the prestressed support rod for supporting open-cut tunnel foundation pits includes multiple support sections 100, each with a connecting flange 101. The connecting flanges 101 of adjacent support sections 100 are attached and fixed by passing through a first fixing bolt 103. Both ends of the support section 100 are provided with outwardly extending pressure-applying sections 200. In this embodiment, support sections 100 of different lengths are selected according to the size of the foundation pit to form a support rod of suitable length. Hydraulic jacks are installed on both sides of the ends of the support sections 100. The extension of the hydraulic jacks causes the pressure-applying sections 200 to move outward and contact the pre-installed brackets on the inner wall of the foundation pit, thereby applying pressure to the inner wall of the foundation pit.

[0046] like Figure 2 As shown, each connecting flange 101 is fixedly connected to a plurality of support inclined plates 102 near the outer wall of the support part 100. In this embodiment, the support force of the support part 100 can be strengthened by the support inclined plates 102.

[0047] like Figure 3 as well as Figure 4 As shown, this is a schematic diagram of the fixing component structure in this embodiment. The ends of the support portions 100 on both sides of the support rod are telescopically connected to movable portions 201. Limit grooves 202 are provided on the movable portions 201. The ends of the movable portions 201 are fixedly connected to the outer wall of the pressure application portion 200. Assembly brackets 104 are detachably connected to both sides of the ends of the support portions 100. A hydraulic jack is installed on the outer wall of the assembly bracket 104, and its telescopic end contacts the pressure application portion 200. Multiple fixing wedges 203 are inserted inside the movable portions 201. A second fixing wedge passes through each fixing wedge 203. In this embodiment, after the moving part 201 is moved outward by the extension of the hydraulic jack and the pressure part 200 contacts the support of the inner wall of the pit, a suitable number of fixing wedges 203 are inserted according to the extension size of the moving part 201. After insertion, each second fixing bolt 204 passes through the fixing wedge 203, and after the fixing wedge 203 is inserted, the fixing wedge 203 is fixed to the moving part 201 by welding. The fixing wedge 203 can limit the movement between itself and the end of the support part 100, thereby supporting the inner wall of the pit.

[0048] like Figure 5 as well as Figure 7As shown, this is a schematic diagram of the monitoring component structure in this embodiment. The ends of the support portions 100 on both sides of the support rod are provided with sliding grooves 106. The inner wall of the sliding groove 106 is provided with sliding protrusions 110. A limiting groove 202 is inserted into the sliding protrusions 110. The end of the moving part 201 inserted into the sliding groove 106 is fixedly connected to a limiting part 207. A first connecting pipe 105 and a second connecting pipe 107 are provided on the inner side of the sliding groove 106. An air inlet one-way valve 205 and a first wireless air pressure sensor 206 are detachably connected to the outer wall of the support portion 100. The air inlet one-way valve 205 is connected to the first connecting pipe 105, and the first wireless air pressure sensor 206 is connected to the second connecting pipe 107. A first inclined plate 210 is rotatably connected to the bottom inner side of the sliding groove 106 by a torsion spring. A second inclined plate 211 is provided at the raised end of the first inclined plate 210. A rubber part 212 is provided between the second inclined plate 211 and the first inclined plate 210. In this embodiment, when the hydraulic jack extends, causing the pressure application part 200 to move the moving part 201 and the limiting part 207 outward, external air enters the space between the limiting part 207 and the sliding groove 106 through the air inlet one-way valve 205. Since the air inlet one-way valve 205 only allows air to enter, when the pressure application part 200, the moving part 201, and the limiting part 207 are pushed towards the sliding groove 106 by the inner wall of the foundation pit, the moving part 201 moves, causing the rubber part 212 to rotate downward, pressing the air below the rubber part 212 into the interior of the second connecting pipe 107. This allows the first wireless air pressure sensor 206 to detect changes in air pressure, thereby detecting whether the prestress has disappeared based on the fluctuations. Furthermore, the first wireless air pressure sensor 206 can accurately locate which support rod has a problem and pinpoint the end of the support rod, eliminating the need for manual inspection and enabling timely detection of changes in the foundation pit prestress support.

[0049] like Figure 8 As shown, this is a schematic diagram of the pressure equalization component structure in this embodiment. The outer wall of the moving part 201 is fitted with multiple C-shaped frames 208 that are opposite each other. Each C-shaped frame 208 has a protrusion 209 fixedly connected to its upper end. The second fixing bolt 204 passes through the fixing wedge 203 and the protrusions 209 on both sides. In this embodiment, different numbers of C-shaped frames 208 are fitted according to the extension length of the moving part 201, so that adjacent C-shaped frames 208 fit together. The C-shaped frames 208 are fixed by the second fixing bolt 204. The multiple C-shaped frames 208 are welded together by welding. This allows the force on the pressure application part 200 and the moving part 201 to be evenly transmitted to the support part 100 when the inner wall of the pit changes, thereby increasing the support strength of the support part 100 and reducing the risk of deformation.

[0050] This embodiment also discloses a three-dimensional support frame for foundation pit support, used to support the aforementioned support rods, such as... Figure 9As shown, this is a schematic diagram of a prestressed support frame structure for foundation pit support in this embodiment. The support frame includes a support channel steel 401 set at the bottom of the support part 100. Supporting vertical piles 400 are detachably connected to both sides of the outer wall of the support channel steel 401. A fixing clamp 402 is provided on the support channel steel 401. The fixing clamp 402 fixes the support part 100 above the support channel steel 401. In this embodiment, the support part 100 can be suspended in the foundation pit by the cooperation of the supporting vertical piles 400 and the support channel steel 401. The fixing clamp 402 can prevent the support rod from shifting during the support process, thus preventing the loss of support effect.

[0051] like Figure 10 As shown, this is a schematic diagram of the fixing component structure in this embodiment. The fixing clamp 402 has connecting parts 403 fixedly connected to both ends. A fixing part 406 is inserted into the inside of the supporting channel steel 401. An insertion groove 408 is provided on the outer wall of the fixing part 406 near the bottom. The insertion groove 408 is engaged with the protrusion near the bottom of the supporting channel steel 401. A fastening bolt 407 is threadedly connected to the bottom of the fixing part 406. A threaded hole is provided on the supporting channel steel 401, and the threaded end of the fastening bolt 407 is threadedly connected to the supporting channel steel 401. A bidirectional screw 405 is rotatably connected to the fixing part 406. Sliding parts 404 are threadedly connected to the outer walls of both sides of the fixing part 406. The sliding parts 404 are inserted into the inside of the supporting channel steel 401. Hexagonal heads are fixedly connected to both ends of the bidirectional screw 405. A rotating pin 409 is threadedly connected to the outer wall of the sliding part 404. The rotating pin 409 connects the connecting part 403 and the sliding part 404. The outer wall is connected, and the connecting part 403 can rotate along the axis of the rotating pin 409. In this embodiment, when fixing the support part 100, the fixing part 406 and the sliding parts 404 on both sides are inserted into the appropriate position inside the support channel steel 401. After the insertion slot 408 is inserted, the fastening bolt 407 is rotated to fix the position of the fixing part 406. The fixing clamp 402 is inserted from the outer wall of the support part 100 near the top. The connecting parts 403 on both sides are connected to the sliding parts 404 by the rotating pins 409 on both sides. By rotating the hexagonal head on either side, the bidirectional screw 405 is rotated, which allows the sliding parts 404 on both sides to drive the connecting parts 403 to move towards each other at the same time. The fixing clamp 402 wraps around the outer wall of the support part 100 and fixes it as the connecting parts 403 on both sides move, thereby increasing the contact area between the fixing clamp 402 and the support part 100 and making the fixing effect better.

[0052] Example 2: Figure 6 as well as Figure 7As shown, this is another preferred embodiment of the present invention. The difference between this embodiment and embodiment 1 is that a rotating shaft 108 is fixedly connected to the outer wall of the connecting flange 101, and a limiting turntable 109 is fixedly connected to the end of the rotating shaft 108. The rotating shaft 108 is inserted into the end of the support part 100, and the limiting turntable 109 is embedded inside the support part 100. In this embodiment, by designing the connecting flange 101 to rotate, when splicing multiple support parts 100 before hoisting, rotating the connecting flange 101 makes the holes between adjacent connecting flanges 101 on both sides face each other, thereby making it easier to pass the first fixing bolt 103 through the hole, and thus making it easier to assemble multiple support parts 100.

[0053] Example 3: As Figure 11 As shown, this is another preferred embodiment of the present invention. The difference between this embodiment and Embodiments 1 and 2 is that the end of the pressure application part 200 is provided with a pressing part 300, and the end of the pressure application part 200 is provided with a connecting channel 305 communicating with the sliding groove 106. A mounting bracket 303 is fixedly connected inside the connecting channel 305, and a return spring 302 is provided on the mounting bracket 303. A sliding rod 301 is slidably connected inside the connecting channel 305, and the sliding rod 301 is fixedly connected to the pressing part 300. In this embodiment, the pressing part 200 causes the sliding rod 301 to slide into the connecting channel 305 and compress the return spring 302 after contacting the inner wall of the pit through the pressing part 300. When the inner wall of the pit deforms, the pressing part 300 moves outward due to the rebound force of the return spring 302. At this time, the pressure inside the sliding groove 106 changes, thereby enabling the monitoring of the condition of the inner wall of the pit.

[0054] Example 4: Figure 11 As shown, this is another preferred embodiment of the present invention. The difference between this embodiment and embodiments 1 and 2 is that the end of the pressure-applying part 200 is provided with a pressing part 300, and the end of the pressure-applying part 200 is provided with a connecting channel 305. A mounting bracket 303 is fixedly connected inside the connecting channel 305, and a return spring 302 is provided on the mounting bracket 303. A sliding rod 301 is slidably connected inside the connecting channel 305, and the sliding rod 301 is fixedly connected to the pressing part 300. A second wireless air pressure sensor 304 is detachably connected to the outer wall of the pressure-applying part 200. The detection end of the second wireless air pressure sensor 304 is connected to the inside of the connecting channel 305. In this embodiment, the pressure change inside the connecting channel 305 can be detected independently by the second wireless air pressure sensor 304, so that when the inner wall of the foundation pit changes, it can be detected in time, and the detection is more accurate.

[0055] Example 5: Figure 12As shown in Figure 13, this is another preferred embodiment of this implementation. The difference between this embodiment and Embodiment 1 is that the first wireless air pressure sensor 206 is replaced with a pressure sensor 213. A telescopic plate 219 is elastically telescopically connected between the second inclined plate 211 and the first inclined plate 210. A groove is provided at the bottom of the second inclined plate 211, and a sliding block 214 is slidably connected inside the groove. A pressing block 215 is fixedly connected to the bottom of the sliding block 214. A telescopic rod 216 is fixedly connected to the lower end of the pressing block 215. A pressing head 217 is slidably connected to the outer wall of the telescopic rod 216. A buffer spring 217 is provided between the end of the telescopic rod 216 and the pressing head 217. 18. In this embodiment, when the pressure application part 200, the moving part 201 and the limiting part 207 are pushed to move towards the sliding groove 106 on the inner wall of the foundation pit, the moving part 201 moves and causes the rubber part 212 to rotate downward. The second inclined plate 211 and the first inclined plate 210 adaptively extend and retract through the telescopic plate 219, so that the lower pressure head 217 moves downward to contact the pressure sensor 213. By monitoring the change of the pressure sensor 213, it is determined whether the prestress has disappeared. The buffer spring 218 can make the lower pressure block 215, the telescopic rod 216 and the lower pressure head 217 located inside the second connecting pipe 107 when the moving part 201 is inside the sliding groove 106 before installation.

[0056] The above description, in conjunction with specific embodiments, provides a further detailed explanation of the present invention. It should not be construed that the specific implementation of the present invention is limited to these descriptions. For those skilled in the art, several simple deductions or substitutions can be made without departing from the concept of the present invention, and all such deductions or substitutions should be considered to fall within the scope of protection defined by the claims submitted herein.

Claims

1. A prestressed support rod for open cut tunnel foundation pit support, comprising a plurality of support parts (100), a connecting flange (101) is arranged on the plurality of support parts (100), the connecting flanges (101) of two adjacent support parts (100) are attached and fixed through a first fixing bolt (103), pressure applying parts (200) which can be extended outward are arranged at both ends of the support part (100), a plurality of support inclined plates (102) are fixedly connected to each connecting flange (101) close to the outer wall of the support part (100), characterized in that, The end of the two side supporting parts (100) of the supporting rod is telescopically connected with a moving part (201), the end of the moving part (201) is fixedly connected with the outer wall of the pressing part (200), the end of the two side supporting parts (100) of the supporting rod is provided with a sliding groove (106), the end of the moving part (201) inserted into the sliding groove (106) is fixedly connected with a limiting part (207), the inner side of the sliding groove (106) is provided with a first connecting pipeline (105) and a second connecting pipeline (107), the outer wall of the supporting part (100) is detachably connected with an air inlet one-way valve (205) and a first wireless air pressure sensor (206), the air inlet one-way valve (205) is communicated with the first connecting pipeline (105), the first wireless air pressure sensor (206) is communicated with the second connecting pipeline (107), the inner bottom of the sliding groove (106) is torsionally connected with a first inclined plate (210), the raised end of the first inclined plate (210) is provided with a second inclined plate (211), and the second inclined plate (211) and the first inclined plate (210) are provided with a rubber part (212) therebetween.

2. The prestressed support rod for open tunnel foundation pit support according to claim 1, characterized in that, The end of the two side supporting parts (100) of the supporting rod is telescopically connected with a moving part (201), the end of the moving part (201) is fixedly connected with the outer wall of the pressing part (200), the end of the two side supporting parts (100) of the supporting rod is provided with a sliding groove (106), the end of the moving part (201) inserted into the sliding groove (106) is fixedly connected with a limiting part (207), the inner side of the sliding groove (106) is provided with a first connecting pipeline (105) and a second connecting pipeline (107), the outer wall of the supporting part (100) is detachably connected with an air inlet one-way valve (205) and a first wireless air pressure sensor (206), the air inlet one-way valve (205) is communicated with the first connecting pipeline (105), the first wireless air pressure sensor (206) is communicated with the second connecting pipeline (107), the inner bottom of the sliding groove (106) is torsionally connected with a first inclined plate (210), the raised end of the first inclined plate (210) is provided with a second inclined plate (211), and the second inclined plate (211) and the first inclined plate (210) are provided with a rubber part (212) therebetween.

3. The pre-stressed support rod for open cut tunnel foundation pit support according to claim 2, characterized in that, The end of the two side supporting parts (100) of the supporting rod is telescopically connected with a moving part (201), the end of the moving part (201) is fixedly connected with the outer wall of the pressing part (200), the end of the two side supporting parts (100) of the supporting rod is provided with a sliding groove (106), the end of the moving part (201) inserted into the sliding groove (106) is fixedly connected with a limiting part (207), the inner side of the sliding groove (106) is provided with a first connecting pipeline (105) and a second connecting pipeline (107), the outer wall of the supporting part (100) is detachably connected with an air inlet one-way valve (205) and a first wireless air pressure sensor (206), the air inlet one-way valve (205) is communicated with the first connecting pipeline (105), the first wireless air pressure sensor (206) is communicated with the second connecting pipeline (107), the inner bottom of the sliding groove (106) is torsionally connected with a first inclined plate (210), the raised end of the first inclined plate (210) is provided with a second inclined plate (211), and the second inclined plate (211) and the first inclined plate (210) are provided with a rubber part (212) therebetween.

4. The pre-stressed support rod for open cut tunnel foundation pit support according to claim 2, characterized in that, The end of the two side supporting parts (100) of the supporting rod is telescopically connected with a moving part (201), the end of the moving part (201) is fixedly connected with the outer wall of the pressing part (200), the end of the two side supporting parts (100) of the supporting rod is provided with a sliding groove (106), the end of the moving part (201) inserted into the sliding groove (106) is fixedly connected with a limiting part (207), the inner side of the sliding groove (106) is provided with a first connecting pipeline (105) and a second connecting pipeline (107), the outer wall of the supporting part (100) is detachably connected with an air inlet one-way valve (205) and a first wireless air pressure sensor (206), the air inlet one-way valve (205) is communicated with the first connecting pipeline (105), the first wireless air pressure sensor (206) is communicated with the second connecting pipeline (107), the inner bottom of the sliding groove (106) is torsionally connected with a first inclined plate (210), the raised end of the first inclined plate (210) is provided with a second inclined plate (211), and the second inclined plate (211) and the first inclined plate (210) are provided with a rubber part (212) therebetween.

5. The pre-stressed support rod for open cut tunnel excavation support according to claim 1, wherein, ​ 6. The pre-stressed support rod for open tunnel foundation pit support according to claim 5, characterized in that, ​ 7. The pre-stressed support rod for open tunnel foundation pit support according to claim 5, characterized in that, ​ 8. The pre-stressed support rod for open tunnel foundation pit support according to claim 1, characterized in that, The outer wall of the connecting flange (101) is fixedly connected with a rotating shaft (108), the end of the rotating shaft (108) is fixedly connected with a limiting turntable (109), the rotating shaft (108) is inserted into the end of the supporting part (100), and the limiting turntable (109) is embedded in the inside of the supporting part (100).

9. A support frame for open cut tunnel excavation support, the support frame incorporating support poles as claimed in claim 1, characterised in that, The supporting stereoscopic frame comprises a supporting channel steel (401) arranged at the bottom of the supporting part (100), and the outer wall of the supporting channel steel (401) is detachably connected with supporting vertical piles (400) on both sides; the supporting channel steel (401) is provided with a fixed clamp (402), and the fixed clamp (402) fixes the supporting part (100) above the supporting channel steel (401).

10. The support frame for open cut tunnel excavation support according to claim 9, wherein, The two ends of the fixed clamp (402) are fixedly connected with a connecting part (403), the inside of the supporting channel steel (401) is inserted with a fixing part (406), the outer wall of the fixing part (406) close to the bottom is provided with an insertion groove (408), the insertion groove (408) is clamped at the protruding part of the supporting channel steel (401) close to the bottom, the bottom of the fixing part (406) is screw-connected with a fastening bolt (407), the supporting channel steel (401) is provided with a threaded hole, the threaded end of the fastening bolt (407) is screw-connected with the supporting channel steel (401), the fixing part (406) is rotatably connected with a bidirectional screw rod (405), the outer wall of the two sides of the fixing part (406) is screw-connected with a sliding part (404), the sliding part (404) is inserted into the inside of the supporting channel steel (401), the two ends of the bidirectional screw rod (405) are fixedly connected with a hexagonal head, the outer wall of the sliding part (404) is screw-connected with a rotating pin (409), the rotating pin (409) connects the outer wall of the connecting part (403) and the sliding part (404), and the connecting part (403) can rotate along the axis of the rotating pin (409).

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