地井联合物探技术在岩溶注浆检测中的应用

Application of Geophysical Prospecting Technology Combined with Ground and Well in Karst Grouting Detection

灰岩地区岩溶地质的发育情况直接影响到铁路桥梁的设计施工,在岩溶发育区域,桥基础通常采用复杂的超长柱桩方式,并且为了降低施工风险,增强施工可控性,常采用框构桥加注浆的方案,因此注浆加固效果的检测评估就显得尤为重要。目前注浆效果检测评估主要以地面物探和钻探相结合的手段为主,但是在特殊的大深度岩溶发育区,该手段很难达到检测要求。本文针对大深度岩溶的发育问题,首先分析了岩溶区域的地球物理特征,并结合某铁路桥梁施工中的实例,制定高密度电法、地震CT(Computed Tomography)法的地井联合物探检测方案,结合钻孔取芯和压水试验进行分析、验证。结果表明,地井联合的检测方案可精细、准确、高效地检测注浆加固效果,对同类型岩溶注浆加固检测工作具有借鉴意义。

The development of karst geology in limestone areas directly affects the design and construction of railway bridges.In karst areas,the bridge foundation usually adopts complex super-long columnpiles.In order to reduce construction risks and enhance construction stability and controllability,the scheme of grouting frame bridge for bridge foundation is often used.Therefore,the detection and evaluation of grouting reinforcement effect is particularly important.At present,the detection and evaluation of grouting effect is mainly based on the combination of ground geophysical prospecting and drilling,but this method is difficult to meet the detection requirements in special large-depth karst development areas.Aiming at the development of deep karst,this paper first analyzes the geophysical characteristics of the karst area,and combines the construction of a certain railway bridge to formulate a joint geophysical detection plan for the ground and well by using high-density electrical and seismic CT methods.Analysis and verification combined with drilling,coring and pressurized water tests show that the combined ground and well detection scheme can accurately and efficiently detect the effect of grouting reinforcement,which is of reference significance for the same type of karst grouting reinforcement detection work.