复杂岩溶地质桥梁桩基础的设计和施工探究

Research on the Design and Construction of Pile Foundation of Complex Karst Geological Bridge

依托广东省某危桥改造多个单位工程项目,针对粤北山区复杂岩溶地质在桩基施工引发漏浆、塌孔等问题,分别提出了不同溶洞高度、填充状态的桩基溶洞处治原则以及桩基设计优化方案。结果表明:工程危桥1采用的片石黏土回填法以及钢护筒跟进法可有效解决单一中小型溶洞问题;而对于溶洞数目多且相互贯通的桥区,危桥2采用避让措施,桩基优化为双排摩擦桩,具有显著减少溶洞处理成本和保障施工安全等优势。经钻芯成孔检测结果得出,项目所采取溶洞处治措施和桩基优化设计都能保证桩身质量完整、检测良好。

Relying on multiple unit engineering projects for the renovation of a critical bridge in a specific region of Guangdong Prov‐ince,this study addresses the challenges associated with pile foundation construction in complex karst geology in the northern mountainous ar‐eas of the province.The issues encountered include grout leakage and sinkholes.Different principles for treating karst caves with varying heights and filling states,as well as optimization schemes for pile foundation design,were proposed.The results indicate that for the first critical bridge in the project,the use of clay backfill and the steel casing follow-up method effectively resolved issues related to single small to medium-sized karst caves.However,for the second critical bridge in the project,which had a larger number of interconnected karst caves,avoidance measures were implemented,and the pile foundation was optimized to a double-row friction pile design.This approach sig‐nificantly reduced the cost of karst cave treatment and ensured construction safety.Based on the results of core drilling and perforation test‐ing,it is concluded that the karst cave treatment measures and the optimized pile foundation design adopted in this project ensure the integri‐ty and good quality of the piles,meeting the required standards for construction.