钢管混凝土桩加固巨型溶洞回填体离心模型试验研究  

Centrifugal Model Test Research on Backfill of Giant Karst Caves Strengthened by Concrete Filled Steel Tube Pile

作　　者：贺琛方 苏谦[1] 苏芮 董敏琪 李艳东 王迅[1] HE Chenfang;SU Qian;SU Rui;DONG Minqi;LI Yandong;WANG Xun(School of Civil Engineering,Southwest Jiaotong University,Chengdu 610031,China;CCCC Second Highway Consultants Co.Ltd.,Wuhan 430056,China;China Railway First Survey and Design Institute Group Co.Ltd.,Xi’an 710043,China)

机构地区：[1]西南交通大学土木工程学院,成都610031 [2]中交第二公路勘察设计研究院有限公司,武汉430056 [3]中铁第一勘察设计院集团有限公司,西安710043

出　　处：《铁道建筑》2022年第12期143-148,共6页Railway Engineering

基　　金：国家自然科学基金(51978588)。

摘　　要：成都—贵阳高速铁路玉京山隧道穿越一巨型溶洞,现场按照“全回填,后开挖,最后采用钢管混凝土桩加固”方式进行了处置,为探究基于此处置方法的土体长期沉降和承载特性,开展钢管混凝土桩加固回填体离心模型试验。结果表明:在隧道自重荷载作用下,土体变形经历了急剧增长、增长减缓和缓慢变形三个阶段,急剧增长阶段产生的沉降最大,缓慢变形阶段持续时间最长;管桩加固模型10年累计沉降为3.76 mm,未加固模型沉降为6.16 mm,加固模型相比于未加固模型沉降减小约39%;试验开始后的310 d内土压力变化较为明显,桩顶土压力减小,桩间土压力增大,桩顶土压力向桩间转移,之后便趋于稳定。研究结果为铁路隧道溶洞处置提供了一种可行方法。The Yujingshan tunnel of Chengdu-Guiyang high speed railway passed through a giant karst cave.The site was treated according to the method of’full backfilling,later excavation and finally reinforced with concrete filled steel tube piles’.In order to explore the long-term settlement and bearing characteristics of the soil mass based on this treatment method,centrifugal model tests of the backfill body reinforced with concrete filled steel tube piles were carried out.The results show that under the effect of the self-load of the tunnel,the deformation of the soil has undergone the three stages of rapid growth,slow growth and slow deformation,with the largest settlement in the rapid growth stage and the longest duration in the slow deformation stage.The 10 years cumulative settlement of the pipe pile reinforcement model is 3.76 mm,and that of the unreinforced model is 6.16 mm.Compared with the unreinforced model,the settlement of the reinforced model is reduced by about 39%.The soil pressure changes obviously within 310days after the start of the test.The soil pressure at the top of the pile decreases,the soil pressure between the piles increases,and the soil pressure at the top of the pile transfers to the pile interval,and then tends to stabilize.The research results could provide a feasible method and scientific basis for the treatment of karst caves in railway tunnels.

关 键 词：铁路隧道 巨型溶洞 离心模型试验 沉降 回填体 钢管混凝土桩 

分 类 号：U45[建筑科学—桥梁与隧道工程]