南昆铁路八渡(K343)滑坡抗滑桩检测与失稳分析

TEST AND STABILITY ANALYSIS OF THE RETAIN PILESFOR BADU(K343)LANDSLIDE IN NANNING-KUNMING RAILWAY

以一维弹性杆理论为基础 ,简要地叙述了声波测桩的基本原理 ,分析了应变波在桩身中的传播过程。论述了 CE2 0 0 1工程仪测桩的工作方法及在南昆铁路八渡滑坡抗滑桩检测的应用实例 ,通过对八渡滑坡抗滑桩的长度、强度及完整性的检测 ,认为抗滑桩失效的主要原因不是抗滑桩强度 ,而是桩深不够且多数植于不稳定的强风化岩层中 ;此外 ,地震和地质雷达检测出滑坡层面 ,主要发生在砂岩强风化层上部与松散层底部 ,进一步说明原抗滑桩为悬浮桩。这为滑坡地带重新构筑抗滑桩设计提供了理论依据。

Based on the theory of one dimensional elastic pole, the fundamental principle of sonic testing for pile is briefly described and the transmitting procedure of strain wave in the pile is analyzed. Besides, the use of CE2000 is also introduced in this paper and a case studied from retain piles detection by means of the device at Badu landslide in Nanning- Kunming Railway is given herein. Through detection of length, strength and integrality of the retain piles, it is suggested that not the strength of the piles but the depth of the piles in soil, which were established in the strongly weathered formation, is responsible for the lost of the slope stability. Further, the landslide interface is identified by seismic and geological radar, which demonstrates that the landslide interface occurred at the upper strongly weathered sand formation and/or at the bottom of the loose formation. This further discloses that the retain piles are suspending/floating. These results have provided powerful basis for design and reconstruction of retain piles in Badu landslide.