岩溶路基加筋防塌治理的简化设计方法  

Simplified design method of reinforcement treatment for karst subgrade collapse

作　　者：吴迪 李艾文 李丹 贾龙[2] 韦学英 吴建建 WU Di;LI Aiwen;LI Dan;JIA Long;WEI Xueying;WU Jianjian(School of Architecture and Transportation Engineering,Guilin University of Electronic Technology,Guilin,Guangxi 541004,China;Institute of Karst Geology,CAGS/Key Laboratory of Karst Dynamics,MNR&GZAR,Guilin,Guangxi 541004,China)

机构地区：[1]桂林电子科技大学建筑与交通工程学院,广西桂林541004 [2]中国地质科学院岩溶地质研究所/自然资源部、广西岩溶动力学重点实验室,广西桂林541004

出　　处：《中国岩溶》2023年第3期538-547,共10页Carsologica Sinica

基　　金：国家自然科学基金项目(No.42067044);广西重点研发计划项目(桂科AB23026028)。

摘　　要：近年来岩溶地区呈高发态势的路面塌陷灾害不断威胁城市交通安全。用回填压实法治理塌陷时,埋入土工织物所形成的加筋垫层,能增强土体稳定性,防止二次塌陷。然而加筋治理方案中筋材的锚固长度分析及受力计算理论相对缺失,现存的加筋体设计方法也较少考虑塌陷发生后加筋治理铺设范围的选择,这些不足严重制约了土工合成材料在岩溶路基塌陷中的工程应用。针对这一现状,提出了一种岩溶路基塌陷后加筋治理的设计方法。该方法采用条分法对筋材上方土拱以下范围的填土进行受力分析,结合筋−土的作用特点,给出了塌陷区和稳定区加筋体拉力的计算公式,进而推导了加筋治理合理锚固长度的计算公式,并梳理了加筋体锚固长度设计流程;在此基础上,基于相关文献的模型试验结果及前人的计算方法对设计方法进行合理性验证,并进一步讨论塌陷宽度、加筋体最大挠度对加筋体拉力和合理锚固长度的影响。结果表明:(1)提出的加筋设计方法计算简洁,所得结果与试验结果更为吻合,由此建立的土工织物加筋垫层治理岩溶区城市路面塌陷的筋材拉力计算理论,对于工程实践具有一定的指导意义;(2)加筋体拉力在塌陷边缘处达到最大,塌陷宽度才是影响加筋体受力和合理锚固长度的主要因素,而加筋体最大挠度对合理锚固长度的影响较小。Karst areas are widely distributed in China,especially in South China.With the proposal of the Belt and Road Initiative,a large amount of infrastructure has to be built in the karst area.However,the diversity of structure and mechanical properties of karst make it difficult for us to construct roads on karst foundations.In recent years,the frequent occurrence of settlement and even collapse of the road surface caused by karst foundations under soil layers of roads has threatened the safety of urban transportation and the development of economy.Therefore,the treatment of karst collapse has become an urgent engineering problem.For the controlling of karst collapse under a complex urban road environment,the treatment of karst collapse by the method of backfilling and compacting is economical in construction and can be finished in short time,but collapses are prone to happen again after treatment.In this case,the treatment can be carried out with geosynthetics,namely filling the geotextile in the subsidence area during the backfilling and compacting process.This kind of treatment utilizes not only the reinforcement effect of geotextiles to achieve the self-stability of the entire reinforced soil system,but also utilizes the filtration performance of geotextiles to prevent the loss of soil particles backfilled,thus addressing both the symptoms and root causes of the collapse.However,the interface interaction between reinforcement and soil is so complex in this method that the corresponding design method of reinforcement is still not clear.In previous studies,the design method of reinforcement focuses on the prevention of collapse before its occurrence.In this kind of method,reinforcement materials are generally used with sufficient anchoring length for full paving.As for the design method of treatment after collapse,there are few studies on the range selection of paving reinforcement.In addition,the maximum tensile force of geotextile will affect its strength design and then impact the overall strength of the reinforc

关 键 词：路基工程 岩溶路基塌陷 加筋治理 锚固长度 设计方法 

分 类 号：U416[交通运输工程—道路与铁道工程]