随钻测试技术在高速公路高边坡灾后优化设计中的应用

Application of testing technique while drilling in post-disaster optimization design of an expressway high slope

由于地形条件限制,有些高速公路边坡无法展开深入勘察,地层和岩体性质掌握不清,会影响到边坡设计,严重者引起滑坡,损失巨大。随钻测试是近年来发展的一项原位测试技术,通过钻孔过程中钻进参数的采集分析,获取工程场地地层情况,评价岩体质量。以某在建高速公路高边坡为例,采用自主研发的随钻测试设备,采集了锚索孔钻孔过程中的钻机钻进参数,通过钻进参数、岩屑特征和临近地段勘察资料的综合分析,识别了边坡的地层情况。结果发现,原勘察资料中认为是中风化灰岩的地层,实际上是崩塌堆积形成的灰岩孤石夹碎石土,整体强度远低于设计值。根据随钻测试的地层识别结果进行了边坡灾后优化设计,边坡变形监测结果验证了优化设计中加固措施的有效性。本文的随钻测试技术和分析方法简单易用,值得在勘察资料不足的边坡工程中推广应用。

Due to the limitation of topographic conditions,some expressway slopes cannot be deeply investigated,and the properties of strata and rock mass are not clear,resulting in slope design errors,serious landslides and huge losses.The testing while drilling is an in-situ testing technique developed in recent years.Through the collection and analysis of drilling parameters in the process of drilling,the engineering site formation conditions are obtained and rock mass quality is evaluated.Taking the high slope of an expressway under construction as an example,the drilling parameters of the drilling rig in the process of anchor cable drilling are collected by using the self-developed test equipment while drilling.Through the comprehensive analysis of drilling parameters,rock debris characteristics and adjacent stratum conditions,the formation conditions of the slope are accurately identified.The results show that the formation is considered to be moderately weathered limestone in the survey,but it is limestone boulder with gravelly soil formed by collapse and accumulation,and the overall strength is far lower than the design value.According to the formation identification results of the testing while drilling,the post-disaster optimization design of the slope is carried out to ensure the stability of the slope,and the slope deformation monitoring results verify the effectiveness of the reinforcement measures in the opeimization design.The testing while drilling technique and the data analysis method in this paper are simple and easy to use,and are worthy of popularization and application in slope engineering with insufficient survey data.