隧道工程岩体完整性新的评价参数及方法

发布时间：2018-04-03 20:57

本文选题：隧道　切入点：工程岩体　出处：《铁道工程学报》2017年02期

【摘要】：研究目的:隧道围岩分级是隧道勘察设计中的重要参数,以往工作中主要通过地质调查法、钻探法、物探方法定性判识隧道岩体完整程度,物探法主要以弹性波速度作为岩体完整性评价的参数,但针对深埋隧道,由于埋深大,难以直接从地表获得隧道洞身岩体的波速值,使得围岩等级的划分缺少依据。本文建立层状岩体模型,通过研究分析岩体几何参数与电性参数的相关关系,拟提出一种新的围岩完整性评价参数及方法。研究结论:(1)基于层状岩体模型电阻率计算公式,推导出岩体几何参数与电性参数的相关关系,提出了一种新的表征岩体完整性的参数——岩体完整性系数Kr;(2)Kr表征完整岩石在单位岩体中所占的比例,Kr值越大,岩体越完整;(3)通过钻孔综合测井试验,论证Kr可以作为评价岩体完整程度的量化指标,初步统计得出Kr与岩体完整程度量化关系表;(4)Kr评价岩体完整性方法可用于铁路隧道勘察设计阶段,也可用于其他地下工程勘察设计阶段。
[Abstract]:Objective: classification of tunnel surrounding rock is an important parameter in tunnel investigation and design. In the past, geological survey, drilling and geophysical exploration were used to determine the integrity of tunnel rock mass qualitatively.In geophysical exploration, elastic wave velocity is mainly used as the parameter to evaluate the integrity of rock mass. However, due to the deep buried tunnel, it is difficult to obtain the velocity value of rock mass directly from the surface of the tunnel, which makes the classification of surrounding rock mass lack of basis.In this paper, a layered rock mass model is established, and a new parameter and method for evaluating the integrity of surrounding rock is proposed by studying and analyzing the correlation between geometric parameters and electrical parameters of rock mass.Conclusion: (1) based on the resistivity calculation formula of layered rock mass model, the correlation between geometric parameters and electrical parameters of rock mass is derived.In this paper, a new parameter to characterize the integrity of rock mass, the integrality coefficient of rock mass, is presented. The ratio of the integral rock to the unit rock mass is larger, the more complete the rock mass is, the more complete the rock mass is, and the more comprehensive logging test is, the more the ratio of the intact rock to the unit rock mass is.It is demonstrated that Kr can be used as a quantitative index to evaluate the integrity of rock mass. The preliminary statistical results show that the quantitative relationship between Kr and the degree of integrity of rock mass can be used to evaluate the integrity of rock mass in the stage of railway tunnel survey and design.Also can be used in other underground engineering survey and design stage.
【作者单位】：中南大学;中铁第四勘察设计院集团有限公司;
【分类号】：U452.1

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