A Blasting Vibration Monitoring Method for Deeply Buried Underground Water Supply Pipelines in Tunnel Step Method Construction

Abstract

The invention provides a blast vibration monitoring method for a buried underground water supply pipeline. The blast vibration monitoring method comprises the following steps of calculating the distance R(upper) between a pipeline and the center of a blasting source of an upper step of a tunnel; when blasting on a lower step of the tunnel, simultaneously arranging measuring points N1 and N2 behind the upper step and a tunnel face, and ensuring that the distances between the two measuring points and the blasting center of the lower step (one half of the height of the lower step of the tunnel is used as a blasting center point) are respectively equal to the R(upper); measuring the vibration speeds V1 and V2 of surrounding rock at the measuring point N1 of the upper step and the measuring point N2 behind the tunnel face of the tunnel; repeating the measuring for three times, and obtaining a formula (V1=nV'2) according to the relationship of vibration speeds at the measuring point N1 and N2; when blasting on the upper step, measuring the vibration speed V'2 at the measuring point N'2 at the L'(back) distance behind the tunnel face; inferring the vibration speed V(pipe) at the pipeline, namely V(pipe)=nV'2; comparing the vibration speed V(pipe) at the pipeline and the control standard of blasting vibration safety of the pipeline, evaluating the safety condition of the pipeline, optimizing a blasting construction plan, and instructing the tunnel control blasting, so as to ensure the pipeline safety. The blast vibration monitoring method has the advantages that the technical problem of monitoring on tunnel blasting vibration of the buried underground pipeline is effectively solved, and the far-reaching influence is realized for the tunnel construction industry.

Description

technical field [0001] The invention relates to the technical field of tunnel construction, in particular to a blasting vibration monitoring method for deeply buried underground water supply pipelines in tunnel construction by step method. Background technique [0002] In recent years, more and more tunnel projects pass through underground water supply pipelines in close distance. When the drilling and blasting method is used for excavation, the blasting vibration of the tunnel poses a serious threat to the safety of the underground water supply pipeline at a short distance. The blasting vibration can easily cause pipeline damage or even cracking, resulting in immeasurable economic losses. [0003] In Li Junsheng (2013) "Protection Measures and Calculation and Analysis of Underground Pipelines Underground Excavation and Excavation of Subway", the calculation and analysis did not consider the impact of blasting vibration on pipelines, and did not propose a blasting monitoring...

AI Technical Summary

Problems solved by technology

like figure 1 As shown, it is the layout of sensors along the depth direction in the prior art, and its main problems and shortcomings: First, the pipeline is located about 5m underground, which is a relatively shallow buried pipeline, and does not involve the blasting vibration monitoring of deep buried pipelines Secondly, on the other hand, by testing the vibration velocity at different depths in the rock body, it can be concluded that the surface vibration velocity value is significantly greater than the vibration velocity value at 5m underground, and this conclusion is not universal; The attenuation law of the blasting seismic wave can be obtained through actual measurement at high speed, but the blasting vibration velocity at the pipeline is not obtained, so as to control the safety of the blasting vibration of the pipeline. This kind of control is very inaccurate and unsafe.

Another existing method is to directly measure the blasting vibration at the bottom of the pipeline by drilling deep holes. This method is very difficult to implement, as follows: first, deep holes are not allowed to be drilled in many cases; , the installation of the sensor is also very difficult, it is difficult to ensure the accuracy of the installation, and it is very difficult to implement

[0005] Therefore, the present invention is aimed at the blasting vibration monitoring method of the deep buried underground water supply pipeline. Due to the large buried depth, if the above method is still used to monitor on the ground, it will be far from the actual blasting vibration of the pipeline, and it cannot ensure that the tunnel blasting vibration The safety of pipelines urgently needs to propose a new monitoring method

Images