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| A New Coefficient andMethodto Appraise Tunnel RockMass Integrity |
| HUA Xi - rui1，LIU Tie2，LIU Jian2 |
| (1. Central South University， Changsha，Hunan 410083， China; 2. China Railway Siyuan Survey and Design Group Co. Ltd，Wuhan，Hubei 430063，China) |
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Abstract Abstract : Research purposes : The classification of tunnel surrounding rocks is an indispensable parameter in the tunnel survey and design stage，which was mainly determined by geological survey， drilling and geophysical methods before. The geophysical metliod mainly use the P - wave velocity to evaluate rock mass integrity，and the P - wave velocity can be usually obtained via shallow seismic reflection method，which renders it hardly applicable to deep buried tunnels since it cannot be directly acquired at tiie depth of tiie tunnel. In this paper，the author established a layered rock mass model to study the relationship between the geometric parameters and the electrical parameters，attempt to find a new method to appraise the rock mass integrity of the surrounding rocks of the tunnel. Research conclusions:( 1 ) Based on the resistivity calculation formula of layered rock mass model， the relationship between the geometric parameters of rock mass and the electrical parameters of rock mass is derived， and a new rock integrity coefficient !r is brought. (2) Kr represents the proportion of intact rock in the unit rock mass，and the larger the Kr value is，the more complete the rock is. (3) The comprehensive logging experiments results show that !r can be used as a quantitative index to evaluate the integrity of rock mass. Through the statistics the quantitative relationship between !r and rock mass integrity is got. (4) K can be used in the railway tunnel survey design stage，and can also be used for other underground engineering survey and design stage.
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Received: 23 December 2016
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2017, Vol. 34 
