Monitoring and measuring method for tunneling supports in bored tunnel

Abstract

A monitoring and measuring method for tunneling supports in a bored tunnel, comprising the following steps: S1, during construction, first conducting blasting along the tunneling outline of a left pilot tunnel, the tunnelling length being the space of a set of grating, so as to form the working face of the left pilot tunnel; and S2, after the tunneling is completed, erecting a grating and a support assembly (12) on the working face of the left pilot tunnel, and drilling monitoring and measuring boreholes. Monitoring in real time a settlement value and an inclination value of a structure can effectively determine the safety state of the on-site construction environment, thereby ensuring safe advancement of the on-site construction; monitoring the deformation of a bored tunnel and analyzing and processing the monitoring data in a timely manner can determine the safety and stability of the stratum and the support structure and determine the level of the tunnelling construction affecting surrounding rocks and the surrounding environment, such that construction safety can be controlled and the impact of the bored tunnelling construction on the surrounding environment can be reduced, thereby ‌taking preventive measures in advance to avoid accidents.

Description

Monitoring and measuring method for excavation support of tunneling TECHNICAL FIELD

[0001] The present application relates to the technical field of subway construction engineering, and in particular to a monitoring and measuring method for excavation support of tunneling. BACKGROUND

[0002] The subway civil engineering includes the construction of station main body building and interval tunnel and the like. This is the core part of the subway civil engineering, and involves the technologies of building, bridge, tunnel and the like. In the process of tunneling construction, the displacement change of the tunneling is the position which is focused on in the construction process, and whether the arch part and the side wall are stable reflects whether the on-site construction is in a safe state.

[0003] The prior art cannot reflect the settlement value and the inclination value of real-time monitoring structure, and cannot effectively determine the safety state of the on-site construction environment. SUMMARY

[0004] In view of the defects in the prior art, the technical problem solved by the present application is that the prior art cannot reflect the settlement value and the inclination value of real-time monitoring structure, and cannot effectively determine the safety state of the on-site construction environment, and a monitoring and measuring method for excavation support of tunneling is provided.

[0005] To achieve the above purpose, the present application provides:

[0006] The monitoring and measuring method for excavation support of tunneling needs to use a tunnel structure, and the tunnel structure comprises:

[0007] The initial support structure of the tunneling, the inner side of the initial support structure of the tunneling is provided with a plurality of support assemblies, the outer side of the initial support structure of the tunneling is formed with a collapse arch, the inner side of the initial support structure of the tunneling is provided with a tunnel arch item secondary lining structure, and the bottom of the tunnel arch item secondary lining structure is provided with a tunnel side wall secondary lining structure.

[0008] The monitoring point buried in the stable rock stratum is used to conveniently, quickly and accurately monitor the excavation deformation of the tunneling, and the steps of the safety monitoring and measuring method comprise:

[0009] S1: first, the blasting is performed along the left pilot hole excavation contour during the construction, and the excavation length is one grid spacing, so as to form a left pilot hole working face;

[0010] S2: after the excavation is completed, the grid and the support assembly are erected on the left pilot hole working face, the monitoring and measuring drill hole is drilled, the monitoring points B, D and Fa are arranged on the arch top and the side wall respectively, the initial support is completed by spraying concrete, and the deformation of the initial support structure arch top and the side wall of the left pilot hole is monitored.

[0011] S3: After the left pilot tunnel excavation face is excavated to a certain distance, excavate the right pilot tunnel working face;

[0012] S4: After excavating the right pilot tunnel working face, erect the grating and support assembly, drill the monitoring and measuring borehole, arrange monitoring points C, E, Ga on both sides of the vault and sidewall, spray concrete to complete the primary support, and monitor the deformation of the primary support structure of the right pilot tunnel vault and sidewall;

[0013] S5: After the right pilot tunnel excavation face is excavated to a certain distance, excavate the middle pilot tunnel working face;

[0014] S6: After excavating the middle pilot tunnel working face, erect the grating and support assembly, drill the monitoring and measuring borehole, arrange monitoring points A, Fb, Gb on both sides of the vault and sidewall, spray concrete to complete the primary support, and form the initial support structure and collapse arch of the tunnel;

[0015] S7: The three excavation faces are staggered by 15 m, and are excavated in layers, and the above steps are repeated to complete the final excavation of the tunnel arch;

[0016] S8: According to the measurement data of monitoring points A, B, C of the tunnel arch, analyze the removal length and timing of the arch support assembly, remove the arch support assembly in sections and zones, construct the removal section of the tunnel arch secondary lining structure, and continue to monitor the deformation of the tunnel arch;

[0017] S9: Excavate the lower part of the station, drill the monitoring and measuring borehole, arrange sidewall horizontal monitoring points H, J, spray concrete to complete the primary support, and monitor the stability of the tunnel sidewall in real time;

[0018] S10: Complete the secondary lining structure of the tunnel, form the tunnel arch secondary lining structure 10 and the tunnel sidewall secondary lining structure, and monitor the tunnel vault in real time through monitoring points A, B, C of the tunnel vault.

[0019] Preferably, the steps in S2 include:

[0020] First, after the tunnel pilot tunnel is excavated, the anchor rod drill is used to form a hole at the position of the tunnel peripheral monitoring point;

[0021] Second, after the hole is formed, the hot-rolled threaded steel reinforcement monitoring and measuring rod is lowered according to the fracture surface position of the monitoring point, the length of the free section of the hot-rolled threaded steel reinforcement monitoring and measuring rod and the position of the fixed end are determined, the outside of the free section is penetrated with an isolation plastic tube, the inside of the soil is sealed with adhesive tape, the exposed end of the steel bar is bound or welded with a steel ruler, and the scale surface of the steel ruler faces upward;

[0022] Third, the other end of the hot-rolled threaded steel reinforcement monitoring and measuring rod is formed into an anchor body with cement slurry, and the plastic tube outside the free section of the steel bar is grouted and reinforced to form the initial support structure of the tunnel;

[0023] Fourth, the orifice is inserted into a hard plastic tube, the tube is exposed to the tunnel primary support concrete surface, and the tube is fixed with cement slurry outside;

[0024] Fifth, the data acquisition is carried out by adopting the total station instrument measurement tunnel primary support concrete surface reflective sheet method, the tunnel arch displacement and the collapsed arch range are calculated according to the data change;

[0025] Sixth, according to the design and specification requirements of the deep deformation monitoring arch position of the tunnel, and according to the design and specification requirements of the monitoring frequency, the monitoring points are repeatedly arranged and data acquisition is carried out in the middle and lower parts of the tunnel primary support according to a-e, and the monitoring work is carried out.

[0026] Preferably, the anchor rod drilling machine forms a hole diameter of 150mm.

[0027] Preferably, the hot-rolled threaded steel reinforcement monitoring measurement rod adopts 12-16 hot-rolled threaded steel, the isolation plastic tube adopts a middle 30 plastic tube, and the exposed size of the steel bar is not less than 1000mm.

[0028] Preferably, the length of the hot-rolled threaded steel reinforcement monitoring measurement rod is not less than 3m, and the drilling hole diameter is not less than 80mm.

[0029] Preferably, the length of the orifice hard plastic tube is not less than 0.35m, the diameter is greater than 100m, and the plastic tube is exposed to the primary support shotcrete surface outside not less than 50mm.

[0030] Preferably, by adjusting the single construction footage range in 0.5-1.5m during the tunnel excavation period, adjusting the steel bar diameter range of 22-32mm of the grid steel frame used for the arch primary support, adjusting the length range of 8-12m of the single support removed during the arch secondary lining construction, the monitoring measurement data of the tunnel is adjusted.

[0031] Compared with the prior art, the advantages of the present application are that:

[0032] The present application can effectively determine the safety state of the site construction environment by monitoring the settlement value and the inclination value of the structure in real time, and ensure the safety of the site construction.

[0033] The present application can control the construction safety and reduce the influence of the excavation construction on the surrounding environment by monitoring the deformation of the tunnel, analyzing and processing the monitoring data in time, judging the safety and stability of the stratum and the supporting structure, judging the influence degree of the tunnel excavation construction on the surrounding rock and the surrounding environment, and providing timely and accurate prediction for the hidden dangers or accidents that may endanger the environment and the construction safety, taking preventive measures in advance, and avoiding accidents. BRIEF DESCRIPTION OF DRAWINGS

[0034] Fig. 1 is a schematic diagram of a monitoring method during construction;

[0035] Figure 2 is a schematic diagram of the monitoring method during operation;

[0036] Figures 3a-3f show a schematic diagram of the monitoring and measurement point layout process of the tunneling excavation;

[0037] Figure 4 is a schematic diagram of the tunneling excavation construction step sequence;

[0038] Figure 5 is a schematic diagram of the tunneling excavation point embedding;

[0039] Figure 6 is a side view of the monitoring and measurement rod.

[0040] In the figure: 1, hot-rolled threaded steel reinforcement monitoring and measurement rod; 2, isolation plastic pipe; 3, anchor body; 4, anchor body; 5, initial support structure of the tunneling excavation; 6, hard plastic pipe; 7, initial support concrete surface of the tunnel; 8, initial support structure of the tunneling excavation; 9, collapse arch; 10, secondary lining structure of the tunnel arch; 11, secondary lining structure of the tunnel side wall; 12, support assembly. DETAILED DESCRIPTION

[0041] The embodiments of the present application are further described in detail below with reference to the accompanying drawings.

[0042] Referring to Figures 1-6, the monitoring and measurement method for the excavation and support of the tunneling excavation includes a tunnel structure, characterized in that the tunnel structure comprises:

[0043] The initial support structure 8 of the tunneling excavation is provided with a plurality of support assemblies 12 on the inner side, and a collapse arch 9 is formed on the outer side of the initial support structure 8 of the tunneling excavation, and the initial support structure 8 of the tunneling excavation is provided with a secondary lining structure 10 of the tunnel arch on the inner side, and the secondary lining structure 10 of the tunnel arch is provided with a secondary lining structure 11 of the tunnel side wall on the bottom;

[0044] The monitoring points embedded in the stable rock layer achieve convenient, fast and accurate excavation deformation monitoring of the tunneling excavation, and the steps of the safety monitoring and measurement method include:

[0045] S1: first, during construction, blasting is performed along the left pilot tunnel excavation contour, and the excavation length is one grid spacing to form a left pilot tunnel working surface;

[0046] S2: after the excavation is completed, the grid and the support assembly 12 are erected on the left pilot tunnel working surface, the monitoring and measurement drill hole is drilled, the monitoring points B, D, and Fa are arranged on the vault and the side wall respectively, the initial support is completed by spraying concrete, and the deformation of the initial support structure of the left pilot tunnel vault and side wall is monitored;

[0047] S3: after the left pilot tunnel excavation surface is excavated to a certain distance, the right pilot tunnel working surface is excavated;

[0048] S4: After excavating the right pilot tunnel working face, the grating and support assembly 12 are erected, monitoring and measuring drill holes are drilled, monitoring points C, E, Ga are arranged on both sides of the vault and sidewall, shotcrete is sprayed to complete the primary support, and the deformation of the vault and sidewall of the primary support structure of the right pilot tunnel is monitored;

[0049] S5: After the right pilot tunnel excavation face is excavated to a certain distance, the middle pilot tunnel working face is excavated;

[0050] S6: After excavating the middle pilot tunnel working face, the grating and support assembly 12 are erected, monitoring and measuring drill holes are drilled, monitoring points A, Fb, Gb are arranged on both sides of the vault and sidewall, shotcrete is sprayed to complete the primary support, and the initial support structure 8 and the collapse arch 9 of the tunnel are formed;

[0051] S7: The three excavation faces are staggered by 15m, and are excavated in layers, the above steps are repeated, and the final excavation of the tunnel arch is completed;

[0052] S8: According to the measurement data of the monitoring points A, B, C of the tunnel arch, the removal length and timing of the arch support assembly 12 are analyzed, the arch support assembly is removed in sections and zones, the tunnel arch secondary lining structure is constructed in the removal section, and the deformation of the tunnel arch is continuously monitored;

[0053] S9: The lower part of the station is excavated, monitoring and measuring drill holes are drilled, horizontal monitoring points H, J are arranged on the sidewall, shotcrete is sprayed to complete the primary support, and the stability of the tunnel sidewall is monitored in real time;

[0054] S10: The secondary lining structure of the tunnel is completed, the tunnel arch secondary lining structure 10 and the tunnel sidewall secondary lining structure 11 are formed, and the tunnel vault is monitored in real time through the monitoring points A, B, C.

[0055] Example Two

[0056] The monitoring and measuring method for the excavation and support of the tunnel is as follows:

[0057] First, after the tunnel pilot tunnel is excavated, the anchor rod drill is used to form holes at the positions of the monitoring points around the tunnel;

[0058] Second, after the hole is formed, the hot-rolled threaded steel monitoring and measuring rod 1 is lowered according to the position of the fracture surface of the monitoring point, the length of the free section of the hot-rolled threaded steel monitoring and measuring rod 1 and the position of the fixed end are determined, the outside of the free section is penetrated with an isolation plastic tube 2, the inside of the soil is sealed with adhesive tape, the exposed end of the steel bar is bound or welded with a steel ruler 3, and the scale surface of the steel ruler faces upward;

[0059] Third, the other end of the hot-rolled threaded steel monitoring and measuring rod 1 is formed into an anchor body 4 with cement slurry, and the plastic tube outside the free section of the steel bar is grouted and reinforced to form the initial support structure 5 of the tunnel;

[0060] Fourth, the orifice is inserted into the hard plastic tube 6, and the tube is exposed to the tunnel primary support concrete surface 7, and the outer tube is fixed with cement slurry;

[0061] Fifth, the data acquisition is carried out by using the total station instrument to measure the tunnel primary support concrete surface reflective sheet method, and the tunnel arch displacement and the collapsed arch range are calculated according to the data change;

[0062] Sixth, according to the design and specification requirements of the deep deformation monitoring arch position of the tunnel, and according to the design and specification requirements of the monitoring frequency, the monitoring points are arranged and the data are collected in the middle and lower parts of the tunnel primary support according to a-e, and the monitoring work is carried out.

[0063] In this embodiment, the anchor rod drilling machine forms a hole with a diameter of 150 mm.

[0064] In this embodiment, the hot-rolled threaded steel reinforcement monitoring and measuring rod 1 adopts 12-16 hot-rolled threaded steel bars, the isolation plastic tube 2 adopts a middle 30 plastic tube, and the exposed size of the steel bar is not less than 1000 mm.

[0065] In this embodiment, the length of the steel bar anchoring body 4 at the other end is not less than 3 m, and the drilling hole diameter is not less than 80 mm.

[0066] In this embodiment, the length of the orifice hard plastic tube 6 is not less than 0.35 meters, the diameter is greater than 100 m, and the plastic tube is exposed to the primary support shotcrete surface 7 by not less than 50 mm.

[0067] In this embodiment, according to the monitoring and measuring data of the tunnel, the single construction footage range during the tunnel excavation is adjusted to be in the range of 0.5-1.5 m, the steel bar diameter range of the grid steel frame used for the arch primary support is adjusted to be in the range of 22-32 mm, and when the arch secondary lining is constructed, the length range of the single support removed is adjusted to be in the range of 8-12 m.

[0068] The present application is not limited to the above-mentioned best embodiment, and anyone can derive other various forms of products under the inspiration of the present application, but regardless of any changes in shape or structure, any technical solution with the same or similar to the present application is within the scope of protection.

Claims

1. A method for monitoring and measuring the excavation support of a tunnel, which requires the use of a tunnel structure, characterized in that, The tunnel structure comprises: The initial support structure (8) of the tunnel is provided with a plurality of support assemblies (12) on the inner side, and a collapse arch (9) is formed on the outer side of the initial support structure (8) of the tunnel, and a tunnel arch second lining structure (10) is arranged on the inner side of the initial support structure (8) of the tunnel, and a tunnel side wall second lining structure (11) is arranged at the bottom of the tunnel arch second lining structure (10); The steps of the safety monitoring and measuring method comprise: S1: first, blasting is performed along the left pilot tunnel excavation contour during construction, and the excavation length is one grid interval, so as to form a left pilot tunnel working face; S2: after the excavation is completed, a grid and a support assembly (12) are erected on the left pilot tunnel working face, a monitoring and measuring drill hole is drilled, monitoring points B, D and Fa are arranged on the vault and the side wall respectively, shotcrete is sprayed to complete the initial support, and the deformation of the vault and the side wall of the initial support structure of the left pilot tunnel is monitored; S3: after the left pilot tunnel excavation face is excavated to a certain distance, a right pilot tunnel working face is excavated; S4: after the right pilot tunnel working face is excavated, a grid and a support assembly (12) are erected, a monitoring and measuring drill hole is drilled, monitoring points C, E and Ga are arranged on the vault and the side wall respectively, shotcrete is sprayed to complete the initial support, and the deformation of the vault and the side wall of the initial support structure of the right pilot tunnel is monitored; S5: after the right pilot tunnel excavation face is excavated to a certain distance, a middle pilot tunnel working face is excavated; S6: after the middle pilot tunnel working face is excavated, a grid and a support assembly (12) are erected, a monitoring and measuring drill hole is drilled, monitoring points A, Fb and Gb are arranged on the vault and the side wall respectively, shotcrete is sprayed to complete the initial support, and the initial support structure (8) of the tunnel and the collapse arch (9) are formed; S7: the three excavation faces are staggered by 15 m, the excavation is performed in layers, the above steps are repeated, and the final excavation of the tunnel arch is completed; S8: according to the measurement data of the monitoring points A, B and C of the tunnel arch, the removal length and removal time of the support assembly (12) of the tunnel arch are analyzed, the support assembly of the tunnel arch is removed in sections and zones, the second lining structure of the tunnel arch is removed in the removed section, and the deformation of the tunnel arch is continuously monitored; S9: the lower part of the station is excavated, a monitoring and measuring drill hole is drilled, side wall horizontal monitoring points H and J are arranged, shotcrete is sprayed to complete the initial support, and the stability of the side wall of the tunnel is monitored in real time; S10: the second lining structure of the tunnel is completed, the tunnel arch second lining structure (10) and the tunnel side wall second lining structure (11) are formed, and the vault of the tunnel is monitored in real time through the monitoring points A, B and C of the tunnel vault.

2. The method for monitoring and measuring of the tunneling excavation support according to claim 1, characterized in that: The steps in S2 comprise: First, after the tunnel pilot tunnel is excavated, a hole is formed at the position of the tunnel peripheral monitoring point by using an anchor rod drilling machine; Second, after the hole is formed, a hot-rolled threaded steel reinforcement monitoring and measuring rod (1) is lowered according to the position of the fracture surface of the monitoring point, the length of the free section of the hot-rolled threaded steel reinforcement monitoring and measuring rod (1) and the position of the fixed end are determined, the outer side of the free section is penetrated by an isolation plastic pipe (2), the inner side close to the soil is sealed by using adhesive tape, and a steel ruler (3) is bound or welded to the exposed end of the steel reinforcement, and the scale surface of the steel ruler faces upward. Third, the other end of the hot rolled threaded steel reinforcement monitoring and measuring rod (1) is anchored by cement slurry to form an anchoring body (4), and the free section of the steel reinforcement is grouted with plastic pipes to form an initial support structure (5) for the tunnel; Fourth, the orifice is inserted into a hard plastic pipe (6), and the pipe is exposed to the surface of the initial support concrete (7) of the tunnel, and the pipe is fixed with cement slurry outside; Fifth, data collection is carried out by measuring the reflective sheet of the initial support concrete surface of the tunnel using a total station instrument, and the displacement of the arch part of the tunnel and the range of the collapsed arch are calculated according to the data changes; Sixth, according to the design and specification requirements for deep deformation monitoring of the arch part of the tunnel, and according to the design and specification requirements for monitoring frequency, monitoring points are arranged and data are collected in the middle and lower parts of the initial support of the tunnel, and monitoring work is carried out.

3. The method for monitoring and measuring of the tunneling excavation support according to claim 2, characterized in that: The anchor rod drilling machine forms a hole with a diameter of 150mm.

4. The method for monitoring and measuring of the tunneling excavation support according to claim 2, characterized in that: The steel reinforcement (1) is made of 12-16 hot rolled threaded steel, and the isolation plastic pipe (2) is made of medium 30 plastic pipe, and the exposed size of the steel reinforcement is not less than 1000mm.

5. The method for monitoring and measuring of the tunneling excavation support according to claim 2, characterized in that: The length of the anchoring body (4) at the other end of the steel reinforcement is not less than 3m, and the diameter of the drilling hole is not less than 80mm.

6. The method for monitoring and measuring of the tunneling excavation support of claim 2, wherein: The length of the orifice hard plastic pipe (6) is not less than 0.35m, the diameter is greater than 100m, and the plastic pipe is exposed to the surface of the initial support shotcrete (7) by not less than 50mm.

7. The method for monitoring and measuring of the tunneling excavation support according to claim 2, characterized in that: Through the monitoring and measuring data of the tunnel, the range of single construction footage during the tunnel excavation is adjusted to be 0.5-1.5m, the diameter of the grid steel frame steel reinforcement for the initial support of the arch part is adjusted to be 22-32mm, and the length of the single support removed during the construction of the second lining of the arch part is adjusted to be 8-12m.

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