不同溶洞处治措施对桩基承载特性的影响研究  

Study on influence of different treatment measures for karst caves on bearing characteristics of pile foundation

作　　者：冯忠居[1] 徐博熙 陈慧芸[1] 夏承明 蔡杰 FENG Zhongju;XU Boxi;CHEN Huiyun;XIA Chengming;CAI Jie(School of Highway,Chang'an University,Xi'an 710064,Shaanxi,China;Sanming Puyan Highway Co.Ltd,Sanming 365000,Fujian,China;Fujian Transportation Construction Quality and Safety Center,Fuzhou 350001,Fujian,China)

机构地区：[1]长安大学公路学院,陕西西安710064 [2]三明莆炎高速公路有限责任公司,福建三明365000 [3]福建省交通建设质量安全中心,福建福州350001

出　　处：《建筑科学与工程学报》2024年第4期151-158,共8页Journal of Architecture and Civil Engineering

基　　金：福建省交通科技攻关项目(201807)。

摘　　要：为探究不同溶洞处治措施对岩溶发育区桩基承载特性的影响,通过有限元软件建立溶洞-桩-岩土体耦合作用模型,对比分析溶洞高度变化情况下,2种不同的溶洞处治措施(回填法和钢护筒跟进法)对桩基承载特性的影响。结果表明:随着溶洞高度增加,2种处治措施下桩基竖向承载力都呈降低趋势;溶洞高度小于10 m时,不同处治措施对桩基竖向承载力影响可忽略,溶洞高度大于10 m则需考虑处治措施对桩基竖向承载力的影响;在回填法处治的溶洞范围内,桩身轴力降幅较大,桩侧摩阻力增加显著,在钢护筒跟进法处治的溶洞中桩身轴力与桩侧摩阻力则基本不变;与钢护筒跟进法相比,回填法更有利于发挥桩侧摩阻力;溶洞高度增加时,2种处治措施下桩侧摩阻力比重均逐渐减小,桩端阻力比重逐渐增大,达到桩基极限承载力时,回填法处治后的溶洞较钢护筒跟进法桩端阻力占整体比例更小。In order to analyze the influence of different treatment measures of karst caves on the bearing characteristics of pile foundations in karst areas,a coupling model of karst caves-piles-rock and soil was established through numerical simulation.The effects of two different treatment measures backfilling method and steel casing follow-up method on the bearing characteristics of pile foundations were compared and analyzed under the condition of changing the height of karst caves height.The results show that the vertical bearing capacity of pile foundation decreases with the increase of the karst cave height under the two treatment measures.When the height of the karst cave is less than 10 m,the impact of the karst cave treatment measures on the vertical bearing capacity of the pile foundation can be ignored.When the height of the karst cave is greater than 10 m,the impact of treatment measures on the vertical bearing capacity needs to be considered.The axial force of the pile body decreases greatly and the pile side friction resistance increases significantly within the scope of the karst cave treated by the backfilling method,but it is basically unchanged in the karst cave treated by the steel casing follow-up method.Compared with steel casing follow-up method,backfilling method is more conducive to exerting the pile side friction resistance.With the increase of the height of the karst cave,the proportion of pile side friction under the two treatment measures gradually decreases,and the proportion of pile end resistance gradually increases.When the ultimate bearing capacity of the pile foundation is reached,the proportion of pile end resistance of karst cave treated by backfilling method is smaller than that of steel casing follow-up method.

关 键 词：岩土工程 岩溶区 桩基 竖向承载特性 回填法 钢护筒跟进法 

分 类 号：U443[建筑科学—桥梁与隧道工程]