CN-121977404-A - Micro-seismic monitoring and segmented advanced blasting collaborative pressure relief method for deep-buried hard rock tunnel

CN121977404ACN 121977404 ACN121977404 ACN 121977404ACN-121977404-A

Abstract

The invention relates to the technical field of safe construction of tunnels and underground engineering, in particular to a method for collaborative pressure relief of micro-seismic monitoring and segmented advanced blasting of a deep-buried hard rock tunnel, which comprises the steps of arranging a pre-built micro-seismic monitoring system along the tunnel wall to acquire and analyze the seismic source parameters of a micro-seismic event and judging whether the seismic source parameters exceed a preset early warning threshold value according to the seismic source parameters; if yes, carrying out sectional advanced blasting pressure relief design based on the source parameters of the microseismic event to obtain blasting parameters, carrying out drilling wall protection and explosive charge detonation on the tunnel wall according to the blasting parameters to obtain the blasted tunnel wall, observing the current surrounding rock response of the blasted tunnel wall, judging whether the current surrounding rock response exceeds a preset early warning threshold value, if yes, judging that the pressure relief is effective, tunneling normally, otherwise, adjusting the blasting parameters or supplementing the pressure relief in the next cycle. Therefore, the problems of passive rock burst risk early warning, poor pressure relief effect, rough parameter control and the like of the deep buried hard rock tunnel under the high ground stress condition in the construction of the drilling and blasting method are solved.

Inventors

ZHANG QI
CHU MAOCHENG
WU ZHIJUN
WU YUEXIU
Yu can
LIU QUANSHENG

Assignees

武汉大学
中国水利水电第十四工程局有限公司

Dates

Publication Date: 20260505
Application Date: 20251210

Claims (10)

1. The method for collaborative pressure relief of micro-seismic monitoring and segmented advanced blasting of the deep-buried hard rock tunnel is characterized by comprising the following steps of: Arranging a pre-built microseismic monitoring system along the line of the wall of a target tunnel so as to acquire and analyze the source parameters of a microseismic event, and judging whether the source parameters exceed a preset early warning threshold value or not according to the source parameters; under the condition that the preset rock burst early warning threshold value is exceeded, performing segment advanced blasting pressure relief design based on the source parameter of the microseismic event so as to obtain blasting parameters; Drilling and wall protecting and charging detonating are carried out on the target tunnel wall according to the blasting parameters so as to obtain a blasted tunnel wall; And observing the current surrounding rock response of the blasted tunnel wall by utilizing a microseismic monitoring system, judging whether the current surrounding rock response reaches an early warning threshold value, if so, judging that the pressure relief is effective, tunneling normally, otherwise, adjusting the blasting parameters or supplementing the pressure relief in the next cycle.
2. The collaborative pressure relief method for micro-seismic monitoring and segmented advanced blasting of a deep-buried hard rock tunnel according to claim 1, wherein the micro-seismic sensors of the micro-seismic monitoring system are arranged in a front-back array mode, the first array of micro-seismic sensors is 80-120 m away from an excavation surface, and the distance between adjacent arrays of micro-seismic sensors is 30-50 m and moves forward dynamically along with the propulsion of the excavation surface.
3. The method for collaborative pressure relief of deep hard rock tunnel microseismic monitoring and segment advanced blasting according to claim 1, wherein the source parameters include energy index, cumulative apparent volume and the extent to which microseismic events are gathered in a predetermined area in front of the tunnel or on the highwall.
4. The method for collaborative pressure relief of micro-seismic monitoring and segment advanced blasting of a deep-buried hard rock tunnel according to claim 3, wherein the preset early warning threshold comprises: Whether the energy index rises rapidly and continuously, and the numerical value increases by more than an order of magnitude; whether the cumulative apparent volume exhibits a sharp rise point; whether the microseismic events are densely clustered in a preset area in front of the tunnel or in the highwall.
5. The method for collaborative pressure relief of micro-seismic monitoring and staged advanced blasting of a deep-buried hard-rock tunnel according to claim 1, wherein the blasting parameters include borehole placement, charge configuration and charge capacity, wherein, The drilling arrangement comprises at least one of the number of advanced blastholes, the aperture, the hole depth, the included angle of the drilling direction and the tunnel axis; The charging structure adopts a sectional uncoupled charging mode; the loading capacity is based on the rock mass property, the ground stress level and the blasting target, and the single-hole total loading capacity is determined by a method of combining a preset empirical formula with numerical simulation.
6. The collaborative pressure relief method for micro-seismic monitoring and segmented advanced blasting of a deep-buried hard rock tunnel according to claim 5, wherein the number of the advanced blastholes is 2-4, the aperture is set to be 100-120mm, the hole depth is 8-12 m, and the included angle between the drilling direction and the tunnel axis is 20 30°。
7. The collaborative pressure relief method for micro-seismic monitoring and segmented advanced blasting of a deep-buried hard rock tunnel according to claim 5, wherein 2 concentrated explosive packages are arranged in each drill hole in the explosive loading structure and are respectively located 1/2 hole depth and 2/3 hole depth from an orifice, each concentrated explosive package is formed by binding a plurality of standard explosive packages and is fixed by a positioner, and an annular air spacer layer is reserved between each concentrated explosive package and the wall of the hole.
8. The collaborative pressure relief method for micro-seismic monitoring and segmented advanced blasting of a deep-buried hard rock tunnel according to claim 5, wherein the loading amount is 5-15kg, and the loading amount ratio of two concentrated drug packs is 1:1 to 1:1.5.
9. The method for collaborative pressure relief of micro-seismic monitoring and segmented advanced blasting of a deep-buried hard rock tunnel according to claim 5, wherein the step of performing hole-drilling wall-protecting and explosive-charging detonation on the target tunnel wall according to the blasting parameters to obtain a blasted tunnel wall comprises the steps of: Based on the drilling arrangement, a PVC pipe with external threads and axial grooves is used as a wall protection component of a drill rod to follow the wall of the target tunnel while drilling; after drilling is completed, the PVC pipe is left in the hole to form a protective wall and a charging channel, explosive is charged into the charging channel according to the charging structure and the charging amount, and the hole opening is blocked; and detonating the explosive according to a preset detonation time sequence to obtain the blasted tunnel wall.
10. The collaborative pressure relief method for micro-seismic monitoring and segmented advanced blasting of the deep-buried hard rock tunnel according to claim 9, wherein a plurality of longitudinal grooves are formed in the outer wall of the PVC pipe, the groove width is 10-20mm, and the depth is 1/3-1/2 of the pipe wall thickness.

Description

Micro-seismic monitoring and segmented advanced blasting collaborative pressure relief method for deep-buried hard rock tunnel Technical Field The invention relates to the technical field of safe construction of tunnels and underground engineering, in particular to a method for collaborative pressure relief of microearthquake monitoring and sectional advanced blasting of a deep-buried hard rock tunnel. Background With the continuous extension of the infrastructure of China traffic, water conservancy and the like to the western complicated mountain areas, the deep-buried long tunnel engineering is increasingly increased. In hard rock stratum with large burial depth and high ground stress, tunnel excavation can cause stress redistribution around the tunnel, and high concentration of energy is easy to form in surrounding rock. Once the stress exceeds the rock mass strength, the accumulated strain energy is released in a violent and abrupt mode, so that rock burst disasters are initiated, the safety of constructors and equipment is seriously threatened, and the engineering progress is influenced. At present, the rock burst prevention and control of a deep-buried hard rock tunnel mainly depends on two major technical approaches, namely, a microseismic monitoring system is adopted for early warning, and rock burst risks are estimated by analyzing the time-space evolution rules of parameters such as the number of microseismic events, energy indexes, accumulated apparent volume and the like. However, the method essentially belongs to passive early warning, has limited early warning effect on 'silent' rock burst without obvious precursor signals or rock burst with extremely short precursor time, and cannot interfere with the inoculation process of the rock burst. And secondly, various pressure relief measures are adopted, such as construction of stress relief holes, advanced drilling pressure relief and the like. However, these methods have problems of limited pressure relief depth and range, insignificant effect, long construction period, etc., and particularly for strong rock burst risk areas with high concentrated energy, it is difficult for conventional pressure relief means to effectively relieve high stress concentration of deep surrounding rocks. In the drilling and blasting method construction, the coupling effect of blasting dynamic load and high ground stress can change the stress state of surrounding rock sharply, so that the rock blasting can be induced, and the active pressure relief is also possible. However, how to combine accurate microseism early warning with a blasting pressure relief technology capable of actively and efficiently releasing deep high stress, to construct a set of active prevention and control system capable of early warning and intervention, and accurately regulate blasting parameters according to early warning information, so as to avoid new surrounding rock damage caused by insufficient pressure relief or excessive blasting, which is a key technical problem to be solved in the art. Therefore, development of a new method capable of accurately identifying rock burst precursors, intelligently deciding pressure relief opportunities, accurately controlling blasting parameters, and ensuring pressure relief effects and construction safety is needed. Disclosure of Invention The invention provides a method for collaborative pressure relief of micro-seismic monitoring and segmented advanced blasting of a deep-buried hard rock tunnel, which aims to solve the problems of passive rock blasting risk early warning, poor pressure relief effect, rough parameter control and the like of the deep-buried hard rock tunnel under the high ground stress condition in the construction of a drilling and blasting method. The embodiment of the invention provides a collaborative pressure relief method for micro-seismic monitoring and segmented advanced blasting of a deep-buried hard rock tunnel, which comprises the following steps of: arranging a pre-built microseismic monitoring system along the line of the wall of a target tunnel so as to acquire and analyze the source parameter of a microseismic event, and judging whether the source parameter exceeds a preset rock burst early warning threshold value or not; under the condition that the preset rock burst early warning threshold value is exceeded, performing segment advanced blasting pressure relief design based on the source parameter of the microseismic event so as to obtain blasting parameters; Drilling and wall protecting and charging detonating are carried out on the target tunnel wall according to the blasting parameters so as to obtain a blasted tunnel wall; And observing the current surrounding rock response of the blasted tunnel wall by using a microseismic monitoring system, judging whether the current surrounding rock response reaches an early warning threshold value, if so, judging that the pressure relief is effective, and tunneling normally, oth