基于DPM系统的风化岩软弱区定位以及性质描述

风化岩体中存在软弱区,这些软弱区导致岩体的力学性能大幅度降低。现阶段往往采用地质钻孔取样对岩体中的软弱区进行定位以及性质分析。但是,由于造价以及工期方面的原因,地质钻孔数量非常有限,这些软弱区很难被有效定位,这在分析风化岩体的力学性能中造成了很大的隐患,成为边坡、基坑设计施工过程中岩体失稳的重要原因。本文介绍了一个风化岩体软弱区定位和性质描述的新方法。该方法应用钻孔过程监测系统(DPM)对土钉、锚杆、抗滑桩以及其他加固体的钻孔过程进行监测,无需取样,通过对钻孔过程数据的分析,实现对软弱区的定位和性质描述。工程实例证明,基于DPM系统的钻孔过程分析方法能够快速有效的定位和描述风化岩体中的软弱区。该方法的出现为风化岩体的工程勘察提供了新的思路,为基于该方法的岩体质量评价系统的建立打下了坚实的基础。

DPM SYSTEM BASED DETECTION AND CHARACTERIZATION OF WEAK ZONES IN WEATHERED ROCK

Weathered rock mass often contain weak zones. The weak zones reduce the mechanical strength of rock mass substantially.To locate and describe the weak zones,drillholes are employed to take rock samples. But,because of reason of economic and construction period,the number of drillholes is limited and the weak zones cannot be located accurately and efficiently. This causes problems in accurately analyzing mechanical properties of rock mass. This kind of problems can induce instability of rock mass in slopes and foundations. This paper introduces a new method to detect and characterize weak zones in weathered rock mass. This method applies Drilling Process Monitoring system(DPM)to monitor the full drilling processes for installation of soil nails,tiebacks,anti-slide piles and so on. Without taking samples,the weak zones can be detected and characterized with the analysis of DPMdata. The case study shows that this method can efficiently and quickly detect and characterize the weak zones in weathered rock mass. This method can be useful to better investigate weathered rock mass for design and construction.