CN-116265716-B - Mechanical tunneling construction method for large-span multi-arch hard rock tunnel

CN116265716BCN 116265716 BCN116265716 BCN 116265716BCN-116265716-B

Abstract

The invention discloses a mechanical tunneling construction method of a large-span multi-arch hard rock tunnel, which comprises the following steps of planning before construction, constructing a middle pilot tunnel, constructing an upper step, constructing a lower step and constructing an inverted arch, wherein in the step I, the whole section of the large-span multi-arch tunnel is divided into seven parts of the middle pilot tunnel, the left hole upper step, the left hole lower step, the left hole inverted arch, the right hole upper step, the right hole lower step and the right hole inverted arch, the middle pilot tunnel, the left hole upper step and the right hole upper step are excavated by adopting a cantilever tunneling machine, and excavating the left hole lower step, the left hole inverted arch, the right hole lower step and the right hole inverted arch by adopting a hydraulic breaking hammer.

Inventors

Jiang Huanchun
LU LUHUA
JI JIAYI
YANG CHAOZHONG
WANG SHOUGUO
LIU LONGKUN
YAN WENLONG
WANG SUHUI
HUANG ZHIHAO
LIU BO
ZHUANG TINGWEI
CHEN BAICAI

Assignees

中建三局集团(深圳)有限公司

Dates

Publication Date: 20260512
Application Date: 20220901

Claims (7)

1. A mechanical tunneling construction method of a large-span multi-arch hard rock tunnel comprises the following steps of planning before construction, constructing a middle pilot tunnel, constructing an upper step, constructing a lower step and constructing an inverted arch, and is characterized in that: in the first step, the whole section of the large-span multi-arch tunnel is divided into seven parts including a middle pilot tunnel, a left hole upper step, a left hole lower step, a left hole inverted arch, a right hole upper step, a right hole lower step and a right hole inverted arch, the middle pilot tunnel, the left hole upper step and the right hole upper step are excavated by adopting a cantilever tunneling machine, and the left hole lower step, the left hole inverted arch, the right hole lower step and the right hole inverted arch are excavated by adopting a hydraulic breaking hammer; According to the construction drawing, determining the construction position of the middle pilot tunnel by using a measuring instrument, operating a cantilever heading machine to the tunnel face to cut and excavate in front, lifting and conveying tunneling slag by using a rear connecting conveyor to enable the tunneling slag to fall into a truck, discharging the slag outside the tunnel by using the truck through a supporting trolley, repairing a flat excavation face after tunneling to a preset excavation footage, measuring and rechecking in time, finishing the underexcavated part until the designed excavation outline is reached, then operating the machine to retreat, the supporting trolley to pick up the tunnel face to perform primary supporting, finishing the primary circulating operation after the supporting is finished, repeating the circulating operation until the middle pilot tunnel is penetrated, constructing a middle partition wall, and enabling the middle concrete to reach the design strength after the construction of the middle pilot tunnel is finished; In the third step, dividing the construction sequence of the left hole upper step and the right hole upper step into a preceding main hole and a following main hole respectively, performing construction respectively, backfilling a gap between surrounding rock and an intermediate wall of the following main hole by using earth and stone, performing construction of the preceding main hole, running a cantilever heading machine to the front main hole face, cutting and excavating the front main hole face, carrying out slag transportation or a slag transportation and excavating machine, using a truck to slag, excavating to a preset excavation footage, repairing a flat excavation face, performing measurement rechecking in time, trimming the undermined part until the designed excavation profile is reached, then operating a machine to retreat, supporting the main hole face, performing primary support, finishing primary circulation operation by supporting, repeating the circulation operation until the preceding main hole is penetrated, and simultaneously, after the staggered distance between the preceding main hole face and the following main hole face reaches the design standard, performing back earth and stone filling, performing cooperative construction until the following main hole is penetrated, and finishing the working procedure is completed with the main hole; In the fourth step, the left and right construction is carried out simultaneously, the excavation side line of the inverted arch of the left hole and the excavation side line of the inverted arch of the right hole are respectively measured, the excavation is carried out in a broken mode in the front by using an excavator provided with a hydraulic breaking hammer, the excavator is used for discharging slag by matching with a dump truck, then the excavator is driven to a preset excavation footage, a flat excavation surface is repaired, measurement rechecking is carried out in time, the undermined part is trimmed until the design excavation outline is achieved, then a machine is operated to retreat, a supporting trolley is lifted to a face of a palm, primary supporting is carried out, the primary supporting is finished, the cyclic operation is repeated until the left hole lower step and the right hole lower step are communicated, and the lower step construction is finished; in the fifth step, according to the tunnel monitoring measurement result, after the deformation values of the left hole lower step and the right hole lower step of the tunnel are in the design allowable range and remain stable, constructing left and right simultaneously, measuring and paying off, crushing and excavating the left hole lower step and the right hole lower step in front by using an excavator provided with a hydraulic breaking hammer, discharging slag by using the excavator in combination with a dump truck, repairing and leveling the excavated surface after tunneling to a preset excavation footage, measuring and rechecking in time, finishing the underexcavated part until the designed excavation contour is reached, operating the machine to retreat, picking the supporting trolley to the face of the tunnel, carrying out primary supporting, finishing the primary cyclic operation after the supporting is finished, repeating the cyclic operation until the inverted arch of the left hole and the inverted arch of the right hole are communicated, and finishing the inverted arch construction of the tunnel.
2. The mechanical tunneling construction method for the large-span arch hard rock tunnel according to claim 1, wherein in the second step, the preset excavation footage of the cantilever tunneling machine is limited by 1-2 cutting heads.
3. The mechanical tunneling construction method of the large-span arch hard rock tunnel according to claim 1, wherein in the second step, the tunneling process of the cantilever tunneling machine is that after the cantilever tunneling machine is in place, a groove is firstly cut horizontally from the bottom of a tunnel face at a high speed, the tunneling machine is moved forward for another time to be in place, a cutting head adopts circular cutting from bottom to top and left to right after the tunneling machine is in place, the bottom is excavated to an arch part, and after the tunneling process is completed, the second trimming is carried out at a low speed to an accurate design section, so that the requirement of the section size is met.
4. The mechanical tunneling construction method for the large-span arch hard rock tunnel according to claim 1, wherein in the second step, the cantilever tunneling machine is cut from the bottom, then the hard rock is cut step by step according to an S-shaped or Z-shaped left-right circular upward cutting route, a right-handed cutting head is selected to cut hard rock, firstly, the right-handed cutting head is cut from the bottom, then the left-handed cutting head is cut from the bottom to the right, the left-handed cutting head is cut from the bottom to the top, and if the higher rock is developed in a joint manner, the cantilever tunneling machine is cut from the bottom in a step-wise cutting manner according to the joint direction of the rock.
5. The mechanical tunneling construction method of a large-span arch hard rock tunnel according to claim 1, wherein in the third step, the staggered distance between the front main tunnel face and the back main tunnel face is 30 meters.
6. The mechanical tunneling construction method for the large-span arch hard rock tunnel according to claim 1, wherein in the fourth step, the preset excavation footage of the excavator provided with the hydraulic breaking hammer is limited by 1-2 breaking hammer lengths.
7. The mechanical tunneling construction method of the large-span arch hard rock tunnel according to claim 1, wherein in the fifth step, the excavator provided with the hydraulic breaking hammer is operated at the bottom of the constructed tunnel body, the hydraulic breaking hammer is kept in a vertical state, front breaking excavation is carried out from top to bottom, when hard rock is met, the angle between the large arm and the hydraulic breaking hammer of the excavator is changed, the excavator is broken sequentially from top to bottom, left to right, and the excavator is repeatedly hit for 2-3 times in each direction for 2-4 seconds, and the hard rock is broken.

Description

Mechanical tunneling construction method for large-span multi-arch hard rock tunnel Technical Field The invention relates to the technical field of large-span multi-arch tunnel construction, in particular to a mechanical tunneling construction method for a large-span multi-arch hard rock tunnel. Background The multi-arch tunnel is a double-hole tunnel formed by connecting two tunnels into a whole through a shared middle wall, and is a novel tunnel structure with development prospect. The arch tunnel has large span, high space utilization rate, smooth line shape, small lead occupation area, certain superiority in the selection of plane lines and tunnel portal positions compared with the repair tunnel, and particularly solves the difficulty in constructing the repair tunnel in complex sections, and becomes a large-span structural form adopted when constructing the tunnel under specific conditions. However, in urban mountain tunnel construction at present, because urban population is dense, the building is dense, noise, vibration and other adverse effects produced by traditional drilling and blasting construction are more difficult to accept, if sensitive buildings such as subways, dense building groups, important national defense buildings and the like exist around, drilling and blasting construction also needs to be approved by schemes of various rights units, the scheme is high in passing difficulty, construction operation is limited, the operation flow is long, the operation efficiency is low, the requirements of safe and quick construction are difficult to meet, in addition, the drilling and blasting construction often has the problems of overexcitation and underexcavation, the profile after excavation is unsmooth and round, the local stress is concentrated, the tunnel profile forming effect is poor, meanwhile, the additional underexcavation amount is increased, the concrete injection amount of subsequent construction is increased, and the construction cost is increased. Disclosure of Invention The invention aims to provide a mechanical tunneling construction method for a large-span arch hard rock tunnel, which aims to solve the problems in the background technology. The invention provides a mechanical tunneling construction method of a large-span multi-arch hard rock tunnel, which comprises the following steps of planning before construction, constructing a middle pilot tunnel, constructing an upper step, constructing a lower step, constructing an inverted arch; in the first step, the whole section of the large-span multi-arch tunnel is divided into seven parts including a middle pilot tunnel, a left hole upper step, a left hole lower step, a left hole inverted arch, a right hole upper step, a right hole lower step and a right hole inverted arch, the middle pilot tunnel, the left hole upper step and the right hole upper step are excavated by adopting a cantilever tunneling machine, and the left hole lower step, the left hole inverted arch, the right hole lower step and the right hole inverted arch are excavated by adopting a hydraulic breaking hammer; According to the construction drawing, determining the construction position of the middle pilot tunnel by using a measuring instrument, operating a cantilever heading machine to the tunnel face to cut and excavate in front, lifting and conveying tunneling slag by using a rear connecting conveyor to enable the tunneling slag to fall into a truck, discharging the slag outside the tunnel by using the truck through a supporting trolley, repairing a flat excavation face after tunneling to a preset excavation footage, measuring and rechecking in time, finishing the underexcavated part until the designed excavation outline is reached, then operating the machine to retreat, the supporting trolley to pick up the tunnel face to perform primary supporting, finishing the primary circulating operation after the supporting is finished, repeating the circulating operation until the middle pilot tunnel is penetrated, constructing a middle partition wall, and enabling the middle concrete to reach the design strength after the construction of the middle pilot tunnel is finished; In the third step, dividing the construction sequence of the left hole upper step and the right hole upper step into a preceding main hole and a following main hole respectively, performing construction respectively, backfilling a gap between surrounding rock and an intermediate wall of the following main hole by using earth and stone, performing construction of the preceding main hole, running a cantilever heading machine to the front main hole face, cutting and excavating the front main hole face, carrying out slag transportation or a slag transportation and excavating machine, using a truck to slag, excavating to a preset excavation footage, repairing a flat excavation face, performing measurement rechecking in time, trimming the undermined part until the designed excavation profile is reached, t