Rockburst risk evaluation method in linear engineering investigation stage

Abstract

The invention relates to a rockburst risk evaluation method in a linear engineering investigation stage. The relation between rockburst and underground engineering burial depth under the condition ofthe overall trend of a line is determined at the initial stage of investigation and design, so that the main burial depth range of high-risk rockburst disasters is determined, and the line and an engineering scheme are reasonably determined. The method comprises the following steps: (1) carrying out function relationship simulation among sigma H, sigma h and depth H by utilizing measured data of the maximum horizontal principal stress sigma H and the minimum horizontal principal stress sigma h obtained by a hydraulic fracturing method along a line area; 2) obtaining the average value Rc of theuniaxial saturated compressive strength of typical hard rocks along the line; 3) considering a circular excavation section, and calculating a function relationship of the maximum tangential stress sigma theta max of the section along with the change of the depth H; and 4) obtaining a change relationship of the hard rock burst coefficient L in the engineering area along with the depth H by using the obtained Rc and sigma theta max and using a Hoek criterion rock burst evaluation method, determining the general depth of the high-risk tunnel according to the standard of rock burst risk grading in the Hoek criterion, and guiding line selection.

Description

technical field [0001] The invention belongs to the technical field of engineering survey, and in particular relates to a rockburst risk assessment method in the linear engineering survey stage, which is especially suitable for use in survey stages such as high-speed railways, highways, and water diversion tunnels in mountainous areas with a high proportion of hard rock tunnels. Background technique [0002] Due to the linear characteristics of linear projects such as railways, highways, and water diversion tunnels, slope restrictions, and the need to avoid major superficial geological disasters, it is often necessary to design a large number of underground projects such as deep-buried long tunnels, which is inevitable in areas where hard rocks are developed. There is a risk of high ground stress rockbursts. Therefore, it is very important to conduct rockburst risk assessment for underground engineering in the line crossing area during the survey and design stages of large-s...

AI Technical Summary

Problems solved by technology

The above method is suitable for the stage when the project plan is basically determined or has already started. It needs to have the measured ground stress and rock compressive strength data, and it is mainly aimed at the work of a single underground project or even the cross-sectional scale. line selection requirements

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