基于BOTDR的滑坡抗滑桩工作状态评价及分析  

EVALUATION AND ANALYSIS OF WORKING STATE OF ANTI-SLIDE PILE WITH BOTDR TECHNOLOGY

作　　者：张磊 施斌[1] 张丹[1] 韩贺鸣 魏广庆 ZHANG Lei;SHI Bin;ZHANG Dan;HAN Heming;WEI Guangqing(School of Earth Sciences and Engineering,Nanjing University,Nanjing 210023;Nanjing University High-tech Institute at Suzhou,Suzhou 215123)

机构地区：[1]南京大学地球科学与工程学院,南京210023 [2]南京大学(苏州)高新技术研究院,苏州215123

出　　处：《工程地质学报》2019年第6期1464-1472,共9页Journal of Engineering Geology

基　　金：国家重大科研仪器研制项目(41427801);国家自然科学基金重点项目(41230636)资助~~

摘　　要：针对传统感测技术存在的问题,本文采用BOTDR分布式光纤感测技术对马家沟滑坡抗滑桩变形进行长期监测分析。在BOTDR监测数据的基础上,对抗滑桩内力进行反演分析,然后与抗滑桩理论设计值进行对比,从抗滑桩内力分布状态及外在环境影响因素两方面对抗滑桩稳定性进行了分析和评价,结果表明:马家沟滑坡在距地表19m和27 m深度处存在两条滑动面;2015年3月之前,马家沟滑坡整体变形较小,处于相对稳定状态,之后抗滑桩逐渐发挥抗滑作用;目前,抗滑桩剪力已接近设计值,抗滑桩处于不稳定状态,需要加强监测;抗滑桩的变形主要受库水位控制,降雨影响较小。库水位降低时,抗滑桩变形增大,库水位升高时,抗滑桩变形趋于稳定。BOTDR监测技术为长期化、精细化评价抗滑桩稳定性状态提供了十分先进的监测手段。Considering the problems of traditional sensing technology,this paper conducts the long-term monitoring and analysis of deep deformation of the anti-slide pile of Majiagou landslide with Brillouin Optical Time Domain Reflectometry(BOTDR) technology. The deflection and internal forces of the anti-slide piles are estimated through the monitored strain data and comparison between the estimated and designed internal forces are made. Taking the hydrological factors into consideration,the working state of anti-slide piles is analyzed and evaluated from the internal and external perspectives. It is shown that there are two sliding surfaces in the Majiagou landslide at the depth of 19 m and 27 m,respectively. Before March 2015,the overall deformation of Majiagou landslide is small,signifying it is in a relative stable state. Then the piles gradually exerts its anti-sliding function. In addition,the shear force of the anti-slide pile is close to the designed value for the present. That is,the anti-slide pile is in an unstable state and needs to be strengthened. The deformation of the anti-slide pile is mainly controlled by the reservoir water level,while the precipitation has a minor effect. Seasonally,the anti-slide pile has an obvious pattern with large deformation when the reservoir water level decreases. Then there is a rapid transition to constant deformation as the reservoir level rises. BOTDR monitoring technology provides a very advanced monitoring means for long-term and meticulous evaluation of the stability state of anti-slide piles.

关 键 词：分布式监测 布里渊光时域反射测量计(BOTDR) 马家沟滑坡 抗滑桩 稳定性分析 

分 类 号：TU441.3[建筑科学—岩土工程]