岩溶区客运专线桥梁桩基沉降和注浆加固研究  

Study on subsidence of bridge pile foundation and its jet-grouting reinforcing on passenger-dedicated railway in karst area

作　　者：张文学[1] 陈壮[1] 刘龙[1] 许成顺[1] 

机构地区：[1]北京工业大学建筑工程学院,北京100124

出　　处：《铁道建筑》2015年第8期27-31,共5页Railway Engineering

基　　金：国家自然科学基金项目(51278015)

摘　　要：新建铁路客运专线设计时速多为300 km以上,对桥梁桩基沉降量要求极高。全面分析岩溶区溶洞对桩基沉降的影响,准确预测岩溶区桩基的沉降量是铁路客运专线桥梁基础设计的难题。以郑徐铁路客运专线徐州特大桥岩溶区桩基工程为依托,通过建立桩基和溶洞地基有限元模型,系统分析了溶洞参数对桩基沉降的影响规律,并对比了不同注浆加固方案对岩溶区桩基沉降的控制效果。结果表明:溶洞顶板厚度、桩尖至岩溶层间岩土层厚度、溶洞尺寸大小及竖向线溶率均对桩基沉降有影响。其中,桩尖至岩溶层间岩土层厚度和溶洞顶板厚度对注浆加固效果影响较大,应根据具体情况进行分析以确定合理的注浆加固方案。As most of the newly constructed passenger-dedicated railway lines operate at 300 km/h or above, foundation subsidence of bridge piles stands as a critical challenge. Therefore, how to thoroughly analyze the influence of karst cave to pile subsidence, and how to predict pile subsidence in an accurate manner stand as two difficult tasks to the foundation design for passenger-dedicated railway bridge. The paper takes the pile foundation of Xuzhou super-long bridge on Zhengzhou-Xuzhou passenger-dedicated railway line as the study object, and builds finite-element model for the analysis of pile foundation and karst-cave foundation accordingly. It looks into the karst parameters and its influence on foundation subsidence, and gives the comparative results of different grouting schemes. The results indicate that relevant factors include thickness of head lining, thickness of rock-soil layer （from pile tip to karst layer ）, cave dimension and linear karst ratio in vertical direction. It needs to be noted that comparatively, the first two exert the greatest influence on grouting results, therefore the grouting scheme applied shall be based on concrete conditions.

关 键 词：桩基 沉降 溶洞 线溶率 

分 类 号：U443.15[建筑科学—桥梁与隧道工程]