CN-116066108-B - Advanced blasting pressure relief rock burst control method for tunnel face of asymmetric high-stress tunnel

Abstract

The invention provides a method for controlling advanced blasting pressure relief rock burst of a tunnel face of an asymmetric high-stress tunnel, and relates to the technical field of tunnel engineering. The method solves the problem that in actual engineering, the tunnel face is under an asymmetric high-stress condition, the stress concentration area has adverse effects on the advanced pressure relief effect, holes are uniformly distributed relative to the face, the number of stress release holes is reduced, the front stress distribution of the tunnel face is effectively improved, the stress concentration area is transferred to the inside, the safety and the construction efficiency of tunnel excavation construction are improved, and the safety of constructors and equipment is ensured.

Inventors

• HE BENGUO
• FENG XIATING
• LIN BO
• TONG QIANG
• XUE RUIHUA
• WANG JIE

Assignees

• 东北大学

Dates

Publication Date

20260508

Application Date

20230113

Claims (1)

1. 1. The advanced blasting pressure relief rock burst control method for the tunnel face of the asymmetric high-stress tunnel is characterized by comprising the following steps of: Step 1, determining a stress concentration area of a tunnel face based on a tunnel engineering geological survey report according to initial ground stress of a tunnel original rock, excavation disturbance stress field distribution and tunnel section geometric characteristics; The method comprises the following steps of 1.1, based on a geological survey report of tunnel engineering, reversing initial ground stress and excavation disturbance stress field distribution of original rock of a tunnel by a numerical simulation method, and determining stress distribution conditions of a tunnel face in tunnel excavation engineering; Step 1.2, obtaining a stress concentration area of the tunnel face according to the spatial relationship between the stress distribution condition of the tunnel face and the geometric shape of the tunnel face; step2, predicting surrounding rock explosion grades by using a rock explosion intensity evaluation method based on tunnel engineering geological survey reports; step 2.1, obtaining a tunnel surrounding rock live condition based on a tunnel engineering geological survey report, wherein the tunnel surrounding rock live condition specifically comprises the burial depth, stratum lithology, initial ground stress, rock uniaxial compressive strength, surrounding rock grading and hydrogeological conditions of the position of the tunnel face surrounding rock; 2.2, drawing a comprehensive judging table of tunnel rock burst strength according to the condition of tunnel surrounding rock, and comprehensively analyzing and predicting surrounding rock burst grades, wherein the surrounding rock burst grades specifically comprise no rock burst, slight rock burst, medium rock burst and strong rock burst; Step 3, determining a tunnel blasting pressure relief control method based on the stress concentration area of the tunnel face and the surrounding rock blasting grade; Step 3.1, determining the arrangement positions of the advanced blasting stress relief holes according to the stress concentration areas of the tunnel face; Step 3.2, determining a rock burst control scheme according to surrounding rock burst grades by matching different advanced blasting pressure relief rock burst control schemes of tunnel face; The advanced blasting pressure relief rock burst control scheme for the tunnel face specifically comprises the following steps: (1) For tunnel face without rock burst and with slight rock burst, blasting stress relief method is not adopted; (2) For a tunnel face with medium rock burst grade, arranging 9-14 holes in a stress concentration area to extend and tunnel a shallow hole of a gun hole for advanced blasting and pressure relief; (3) For tunnel face with strong rock burst grade, arranging 3-5 holes deep hole advanced blasting pressure relief in the stress concentration area, and if the rock burst grade is strong, matching with 9-14 holes extending tunneling gun hole shallow hole advanced blasting pressure relief for use, namely arranging shallow holes at the periphery of the stress concentration area; The step 3.2 specifically comprises the following steps that the construction basis of the advanced blasting pressure relief rock burst control scheme of the tunnel face comprises a construction section view, a pressure relief hole layout view and a blasting parameter table; step 4, checking the effect after each blasting; checking the blasting effect in the step 4; (1) Checking whether the explosion rejection phenomenon exists or not, and if the explosion rejection phenomenon exists, processing according to the blind cannon processing flow in the explosion safety regulations; (2) If the explosion rejection phenomenon does not exist, observing an explosion crushing area and an explosion breaking area: according to the observation of the hole opening, the explosion crushing area is characterized in that the original blast hole center line is taken as an axis, the diameter is 50-70 mm, cracks are increased in the diameter of 100-160 mm, the explosion is judged to be caused, the rock mass in the range has obvious loosening effect, the explosion cracking area is determined according to the rock mass damage condition in the range, and the high ground stress in the explosion cracking area and the explosion vibration area is effectively released.

Description

Advanced blasting pressure relief rock burst control method for tunnel face of asymmetric high-stress tunnel Technical Field The invention relates to the technical field of tunnel engineering, in particular to a rock burst control method for advanced blasting and pressure relief of a tunnel face of an asymmetric high-stress tunnel. Background The rock burst is a phenomenon that the tunnel surrounding rock originally in a true three-dimensional high-stress occurrence environment is changed in stress path due to excavation when the tunnel and underground engineering pass through hard surrounding rock and are in a high-ground-stress area, the surrounding rock is suddenly destroyed due to the release of ground stress, and the large elastic strain energy in the interior is released along with the ejection, throwing, sound and the like of a rock mass, and the main characteristics are dramatic and abrupt. The influence of rock burst on tunnel construction is mainly represented as worsening construction environment, causes damage and destruction to personnel, equipment and tunnel primary support, increases the security risk, reduces the efficiency of construction. The rock burst is increased along with the rock burst risk, and particularly when the rock burst is strong and extremely strong, the occurrence of the rock burst cannot be completely controlled by only supporting, and the blasting stress relief method is a means for effectively controlling the rock burst. The method is characterized in that the surrounding rock weakening method is characterized in that the surrounding rock structure is modified through advanced drilling and proper charging, so that the rigidity of rock mass in a stress concentration area near a tunnel face is reduced, the rock mass in the influence range of drilling and blasting becomes weaker force transmission medium, deformation is increased, the energy distribution state in local surrounding rock is adjusted, the stress concentration degree is improved, and a concentration area is transferred to the front of the tunnel face, so that the purpose of preventing and treating rock burst is achieved. In the tunnel excavation process, the stress of the tunnel face is always in an asymmetric state, and the hole distribution mode of the current blasting stress relief method mainly adopts the mode of uniformly distributing holes on the tunnel face, so that stress relief holes are not arranged in consideration of stress concentration areas formed by asymmetric high stress existing on the tunnel face, a large number of stress relief holes are arranged, manpower and material resources are wasted, and even rock burst is induced in advance due to improper arrangement. Therefore, the application carries out standard hole arrangement on different rock burst grades aiming at stress concentration areas, reduces the number of stress release holes relative to the uniform hole arrangement of the tunnel face, more effectively improves the front stress distribution of the tunnel face, transfers the stress concentration areas to the inside, improves the safety and the construction efficiency of tunnel excavation construction, and ensures the safety of constructors and equipment. Disclosure of Invention Aiming at the defects of the prior art, the invention provides a rock burst control method for advanced blasting and pressure relief of an asymmetrical high-stress tunnel face. The front stress distribution of the tunnel face with rock burst risk is effectively improved, the stress concentration area is transferred to the inside, the safety and the construction efficiency of tunnel excavation construction are improved, and the safety of constructors and equipment is guaranteed. The advanced blasting pressure relief rock burst control method for the tunnel face of the asymmetric high-stress tunnel specifically comprises the following steps: Step 1, determining a stress concentration area of a tunnel face based on a tunnel engineering geological survey report according to initial ground stress of a tunnel original rock, excavation disturbance stress field distribution and tunnel section geometric characteristics; The method comprises the following steps of 1.1, based on a geological survey report of tunnel engineering, reversing initial ground stress and excavation disturbance stress field distribution of original rock of a tunnel by a numerical simulation method, and determining stress distribution conditions of a tunnel face in tunnel excavation engineering; And 1.2, obtaining a stress concentration area of the tunnel face according to the spatial relationship between the stress distribution condition of the tunnel face and the geometric shape of the tunnel face. Step2, predicting surrounding rock explosion grades by using a rock explosion intensity evaluation method based on tunnel engineering geological survey reports; step 2.1, obtaining a tunnel surrounding rock live condition based on a tunnel engineering