Mechanical analysis model of adjacent buried pipeline under tunnel excavation and blasting load and determination method of vibration velocity control standard

Abstract

The invention discloses a mechanical analysis model of adjacent buried pipeline under tunnel excavation and blasting load and a determination method of vibration velocity control standard. The mechanical analysis model includes pipe transverse and longitudinal mechanical model under tunnel excavation unloading and blasting disturbance. The vibration velocity control standard is determined by comparing the calculated value of mechanical analysis model with the theoretical value of pipe failure. The buried pipeline is regarded as the elastic ring in the elastic medium of the soil in the lateralmechanics analysis model of the pipeline under the influence of tunnel excavation and unloading. In the longitudinal mechanical analysis model of pipe under the influence of tunnel excavation and unloading, the pipe is regarded as a Winkler foundation beam supported on soil. The pipe under the influence of tunnel blasting disturbance is regarded as a viscoelastic foundation beam supported on soil.The theoretical value of pipeline failure is determined according to von Mises yield criterion. The invention realizes the quantitative analysis of the influence of tunnel excavation blasting on thepipeline, so that the material performance of the pipeline can be brought into full play and the construction progress of the tunnel is accelerated.

Description

technical field [0001] The invention relates to the field of tunnel construction environment impact, in particular to a mechanical analysis model of adjacent buried pipelines under the action of tunnel excavation and blasting loads and a method for determining vibration velocity control standards. Background technique [0002] With the continuous advancement of urban three-dimensional traffic construction in my country, the blasting and excavation of tunnel projects adjacent to existing buried pipelines has become one of the key factors affecting the safe operation of pipelines. In order to ensure the operation safety of the pipeline during construction, many projects have determined the safe vibration velocity peak value of the surface particle of the pipeline based on practical experience. This value can better guide the blasting construction operations of adjacent tunnels and balance the construction safety and construction progress to a certain extent. contradiction. ...

AI Technical Summary

Problems solved by technology

[0003] Although in the blasting construction of the actual tunnel adjacent to the existing pipeline, the above-mentioned method for determining the peak value of pipeline safety vibration velocity combined with engineering experience has been gradually formed, but due to the lack of theoretical guidance, the standard value given by it is still relatively conservative. Limiting the progress of tunnel construction

In the relevant theoretical analysis of similar problems, most of them did not comprehensively consider the stress state and dynamic characteristics of the pipeline under the joint action of the additional load of construction settlement caused by tunnel excavation, the internal pressure of the pipeline and the blasting load, and often only considered the blasting load alone In fact, once the tunnel is excavated, the stress and deformation state of the corresponding pipeline has changed, coupled with the coupling effect of internal pressure and blasting load, the pipeline will be in a more unfavorable stress state, so the existing The theoretical analysis process is bound to overestimate the resistance of pipeline materials, which is not conducive to the operation safety of pipelines

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