CN-115898422-B - Tunnel hard rock advanced pilot tunnel expansion and excavation construction method

Abstract

The invention relates to the technical field of underground tunnel construction, in particular to a construction method of tunnel hard rock. Dividing the working surface of the upper step excavation into a milling surface and an expanding surface of the pilot tunnel from left to right in sequence, and constructing the pilot tunnel and the expanding surface in parallel. The tunnel hard rock advanced pilot tunnel expanding and excavating construction method has the advantages that the expanding and excavating surface adopts drilling and breaking hammer to excavate, the upper step milling quantity is reduced, the pick consumption is reduced, the comprehensive cost is lower, the generation of dust is reduced, the environment is protected, and the method is favorable to the environment, and has higher use value compared with the traditional step milling and excavating process.

Inventors

• LIU ZHENSHAN
• YANG FENGMING
• ZHANG XU
• LI JINGXIN
• FU JUNSHENG
• LIU ZIQI
• LI XIN
• LUAN XIAOQIANG
• TAN BAOHUI
• LIU ZICHAO
• SHEN GUANGJUN
• LIU ZHOULI
• HE DAWEI
• LIN TAO
• JING SHENQUAN

Assignees

• 中交第一航务工程局有限公司
• 中交一航局第三工程有限公司

Dates

Publication Date

20260508

Application Date

20221129

Claims (4)

1. 1. The method is characterized in that the construction method is a large-section hard rock non-explosive underground excavation tunnel construction method suitable for rock strength of 80-120 mpa, an upper step excavation working face is divided into an advanced pilot hole milling face and an expanded excavation face from left to right in sequence, and advanced pilot hole and expanded excavation parallel construction is adopted, and the method specifically comprises the following steps: S1, advanced geological forecast and surrounding rock monitoring measurement The advanced pilot tunnel method is adopted for excavation, the section parameters of the advanced pilot tunnel comprise that an arc with the designed radius of an arch part of 1.52m is connected with an excavation contour line, the excavation height is 6.2m, the excavation width is 8.7m, the excavation surface of the advanced pilot tunnel occupies 49% of the section area of an upper step, the monitoring quantity of surrounding rock of the advanced pilot tunnel comprises a settlement observation point of the arch part of the pilot tunnel and a horizontal convergence observation point of the arch waist, one section is arranged at each 5m of the settlement observation point and the horizontal convergence observation point of the surrounding rock of the advanced pilot tunnel, corresponding geological advanced forecasting is needed to ensure the safety and stability of the advanced pilot tunnel, so that whether bad geological conditions exist in a certain range outside the contour line of the surrounding rock of the pilot tunnel is ascertained, the advanced geological forecasting of the pilot tunnel is carried out by adopting a ground penetrating radar method, and the advanced geological forecasting and the monitoring measurement of the surrounding rock are carried out in two stages according to the site construction conditions: The first stage, arranging dome circumferential ground penetrating radar measuring lines at the contour line position of a pilot tunnel excavation face, wherein the point measuring distance is not more than 20cm, the radar detection direction is 10 degrees outwards in a ring shape, and the ground penetrating radar advanced prediction is carried out every 20m tunneling along the excavation direction to detect surrounding rock conditions outside the dome contour line of the pilot tunnel; the second stage, arranging a radar measuring line along the axial direction of the tunnel at the vault and the arch waist position of the pilot tunnel every 4m of tunneling of the pilot tunnel, wherein the detection direction is radial outwards, the point measurement distance is 20cm, and detecting the surrounding rock condition behind the vault and the arch waist position of the pilot tunnel; S2, paying off the excavated contour line Measuring an excavation contour line by adopting a total station before per shift excavation, and marking by adopting red paint, wherein the circumferential spacing of points is not more than 40cm; s3, advanced pilot hole milling and digging The advanced pilot tunnel milling and digging area is 35m 2 , the ballast is transported to a ballast disposal site by adopting a loader and a dumper in cooperation with loading, the advanced pilot tunnel milling and digging ruler is judged according to the rock strength, the single-cycle length range is controlled to be 1.2 m-2.0 m, the single-cycle operation time is controlled to be within 11 hours, the distance between the advanced pilot tunnel and the digging surface is kept within 20m, and the dust removal adopts airborne special dust removal equipment; S4, excavating the expanding excavation surface The method comprises the steps of expanding the excavation section parameters, namely, the excavation height is 6.2m, the excavation width is 8.06m, the expanded excavation section occupies 51% of the upper step section area, the excavation surface excavation adopts a drilling and oil hammer excavation scheme, the expanded excavation surface drilling parameters comprise the aperture of 110mm, the hole depth of 5m, the horizontal and vertical hole distances of no more than 40cm, the operation duration is controlled to be 4-6 hours, the oil hammer excavation construction single-cycle construction is carried out at the interval between two steel frames of an advance scale, the diameter of an oil hammer drill rod is required to be larger than the aperture of a drilling hole, the construction average efficiency is 5-6 square/hour, the expanded excavation construction and the advanced pilot tunnel milling are required to be carried out in parallel, and after the expanded excavation construction is completed, the development machine is required to withdraw from the profile line to be trimmed, the outline shape smoothness of the excavation is ensured, and the excavation quality is improved; s5, upper step support The single-cycle support is 2 steel frame intervals of the footage, and the advanced pilot tunnel guniting protection is synchronous with the primary support guniting circulation; S6, excavating lower steps and inverted arches The lower step and the inverted arch are excavated by adopting an oil hammer, and construction equipment is operated by adopting a PC500 excavator plus SG4500 tower breaking hammer; the ballast scarifying and loading equipment adopts a PC360 excavator, and the ballast scarifying equipment adopts a 20-cube dump truck for transportation.
2. 2. The tunnel hard rock advanced pilot tunnel expansion and excavation construction method according to claim 1, wherein the construction method adopts a dust removal method, and specifically comprises the following steps: c1, arrangement of ventilation ducts A group of variable-frequency axial flow fans are arranged at the hole, the power of a press-in type air supply is 2×110KW, the diameter of a ventilation pipeline is 2m, the pipeline is arranged by leaning against the side arch part of the excavation surface, and the distance between an air outlet and the excavation surface is not more than 10m; C2, advanced pilot tunnel dust removal arrangement Adopting an advanced pilot tunnel method for construction, adopting an onboard dust removing device for dust falling, wherein the motor power of the onboard dust removing device is 2 multiplied by 37KW, the onboard dust removing device is arranged on a platform at the top of a tunneling machine, a vibration reduction rubber backing plate is arranged at the bottom of the onboard dust removing device, the power supply voltage is consistent with that of the tunneling machine, and 1140V high-voltage cables are used for access; c3, enlarging digging surface dust removing arrangement In order to secondarily purify the residual dust of the air discharged by the advanced pilot tunnel, an XCS1500 tunnel dust removing vehicle is arranged on the left side wall of the step on the expanding digging surface, the vehicle adopts the mechanisms of water atomization, filtration and water film dust removal, the dust-containing gas is sucked into an air duct and is sent into a dust remover, the dust gas is fully mixed with high-pressure water mist in the dust remover, the gas and the liquid are separated through a plurality of layers of metal filter screens, finally clean air is discharged through an air outlet, dust and water form slurry, and the slurry is pumped into a temporary sedimentation tank in the hole; the XCS1500 tunnel dust removal vehicle is arranged in parallel with the surface expanding equipment, a ballast discharging channel is reserved in the middle, and the distance between the air suction pipeline opening of the dust removal vehicle and the advanced guide opening is not more than 2m; C4, watering spray dust removal arrangement In order to purify polluted air discharged by the XCS1500 tunnel dust removal vehicle again, the temperature in a hole is reduced, a spray pipeline is circumferentially arranged on the primary supporting surface of an upper step, a water tank and a booster water pump are arranged, and the distance between the spray arrangement section and the tail discharge pipe orifice of the dust remover is 5m.
3. 3. The method for enlarging and excavating a hard rock pilot tunnel of the tunnel according to claim 1, wherein the step S3 is characterized in that the pilot tunnel is subjected to milling and excavating operation by an XTR7/360 cantilever heading machine.
4. 4. The tunnel hard rock advanced pilot tunnel expansion and excavation construction method according to claim 1, wherein the step S4 is characterized in that a ZYS113 three-arm drill jumbo is adopted for auxiliary drilling of an expanded and excavated rock surface, and a PC500 short-arm excavator and SG4500 tower type breaking hammer is adopted as oil hammer excavation construction equipment.

Description

Tunnel hard rock advanced pilot tunnel expansion and excavation construction method Technical Field The invention relates to the technical field of underground tunnel construction, in particular to an advanced pilot tunnel expansion and excavation construction method for tunnel hard rock. Background At present, the excavation method in the non-explosive hard rock except TBM at home and abroad mainly comprises the methods of cantilever tunneling, milling, drilling and splitting integrated machine, hydraulic splitting, chemical expanding agent, rock cutting and the like. Through the research of the construction engineering in the early stage at home, the milling and digging of the cantilever excavator is gradually becoming core equipment in the non-explosive excavation construction at present, and the application of the cantilever excavator in various construction fields is wider. However, when the rock strength reaches 80-120 mpa, the hard geological condition can increase the abrasion and damage to equipment, the equipment fault rate is increased along with continuous deep tunneling, and the construction efficiency is reduced. This not only entails expensive excavation costs, but also increases construction pressures. In view of the above, it is necessary to design a new construction method for enlarging and excavating the hard rock pilot tunnel of the tunnel, which is suitable for the condition that the rock strength is 80-120 mpa, so as to fully exert the advantages of mechanical equipment and solve the problems of progress, cost, construction period and the like. In addition, at home and abroad, the dust removal of the cantilever type heading machine milling and digging process is concentrated to be pumped out of the hole by adopting a jet fan, and the dust is discharged to the outside after being filtered by a dry/wet type dust remover. The prior dust removal process has the following problems in the early construction: 1. the jet fan has long pipeline arrangement and high maintenance cost. The flour dust is crossed with a plurality of construction working surfaces, so that the damage and maintenance are frequent, and the flour dust content of the crossed operation exceeds the standard, thereby influencing the construction progress; 2. The dry/wet dust collector has poor filtering effect, dirty air can not meet the discharge standard, the slurry discharge treatment is difficult, and the civilized construction and the environmental protection are affected; 3. the jet fan is fixed in position, cannot move, cannot effectively solve dust on an operation surface, is poor in construction environment, and is not beneficial to health of operators. In view of the above, a dust removing method matched with a tunnel hard rock advanced pilot tunnel expansion and excavation construction method needs to be researched, and dirty air in a tunnel is purified in a layer-by-layer dust removing mode, so that the problems of various aspects such as progress, cost and construction period are solved. Disclosure of Invention The invention aims to provide a rapid construction method suitable for hard rock excavation of a non-explosive tunnel, which adopts equipment such as a cantilever tunneller, a rock drill trolley, a breaking hammer and the like for combined excavation. The technical scheme adopted by the invention is that the construction method is characterized in that the construction method is a large-section hard rock non-explosive underground excavation tunnel suitable for rock strength of 80-120 mpa, an upper step excavation working surface is divided into an advanced pilot hole milling surface and an expanded excavation surface from left to right in sequence, and parallel construction of the advanced pilot hole and the expanded excavation is adopted, and the method specifically comprises the following steps: S1, advanced geological forecast and surrounding rock monitoring measurement The method comprises the steps of excavating by adopting an advanced pilot tunnel method, wherein the section parameters of the excavated advanced pilot tunnel comprise that an arc with the designed radius of an arch part of 1.52m is connected with an excavation contour line, the excavation height is 6.2m, the excavation width is 8.7m, the excavation surface of the advanced pilot tunnel occupies 49% of the section area of an upper step, the monitoring quantity of surrounding rock of the advanced pilot tunnel comprises a settlement observation point of the arch part of the pilot tunnel and a horizontal convergence observation point of the arch part, one section is arranged at each 5m of the settlement observation point and the horizontal convergence observation point of the monitoring quantity of the surrounding rock of the advanced pilot tunnel, the corresponding geological advanced forecasting is required to be carried out for ensuring the safety and stability of the advanced pilot tunnel, so as to find out whether the poor geological c