Determination Method of Volume Joint Number of Jointed Rock Mass Based on Borehole Camera Technology

Abstract

The invention discloses a method for determining the volume and joint number of jointed rock mass based on drilling camera technology, which is applied to the technical field of rock mass integrity assessment and includes the following steps: S1. Selecting a surface area per unit area on the surface of the rock mass to be tested ; S2, measure the rock mass surface joint number Js of the surface area of ​​the unit area, the joint spacing H and the inclination angle θ of the joint and the horizontal roadway; S3, drill holes on the surface area of ​​the unit area, and measure the number of joints inside the rock mass Jc; S4. Comparing the joint spacing H measured in step S2 with the sine and cosine values ​​of the joint inclination angle θ to determine the volumetric joint number Jv of the rock mass. The present invention comprehensively considers the internal joint Jc and the surface joint Js to calculate the volume joint Jv, the consideration factors are more comprehensive, and the calculation is more accurate and fast.

Description

technical field [0001] The invention relates to the technical field of rock mass integrity evaluation, and more specifically relates to a method for determining the volume joint number of jointed rock mass based on borehole camera technology. Background technique [0002] In the prior art, methods for calculating the volumetric joint number Jv of rock mass include direct measurement method, distance method, and strip number method. Among them, the direct measurement method is to directly count the number of joints in the rock mass per unit volume, but the requirements for the site conditions are relatively large in use, and the condition of the free surface must be good. The spacing method refers to calculating the number of cracks per unit volume of rock mass by measuring the spacing of each group of structural planes in the rock mass and using the average value: [0003] Jv=S1+S2+...+Sn+Sk, [0004] In the formula, Sn is the number of joints of the nth group of joints pe...

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Problems solved by technology

[0004] In the formula, Sn is the number of joints of the nth group of joints per meter long survey line, and its value is equal to the reciprocal of the average spacing of the same group of joints in the survey line of sufficient length; Sk is the number of non-grouped joints per cubic meter of rock mass; The problem with this method is that the distribution of spacing in the actual rock mass is very uneven, or sometimes the length of the side line will be greater than 1m because the joint group is obliquely intersected with the surface of the unit body

The problem with this is that the correction coefficient comes from engineering experience and cannot be derived theoretically

The calculation result is not very accurate

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