岩溶对江西湖口大桥基础选择的控制作用

The Controlling Role of Karst in Selecting the Foundation of Hukou Bridge in Jiangxi Province

从湖口大桥区域环境地质条件出发,阐述了岩溶产生和发育的内在因素,指出溶洞为岩溶发育的普遍形态;从岩溶形态的平面分布、灰岩的不同时代、节理裂隙、断层以及地层分界面等几个方面论述了岩溶发育的特征和规律,分析了岩溶发展的趋势,认为目前桥址区岩溶已处于停滞发展阶段,对大桥两个主塔墩基础的选择给出了原则性建议,并对三个桥墩基础设计方案做了分析和评价。通过综合勘察,最终验证K19+224～K19+254地段(弱岩溶发育区和岩溶不发育区)为西塔墩位置,东塔墩基础则选择在坚硬的砂岩地层中。

Referred to the regional environment geological condition of Hukou bridge,this paper describes the internal factors of the emergence and development of karst,and indicates cave is the common form of karst development.and based on the analysis of the plane distribution of karst form,the vary ages of limestone,joint cracks,faults and stratum interface,this paper also discuses the characteristics and laws of karst development,analyzes the tendency of karst development,thinks the karst development is at a relative standstill stage in bridge area,presents the principle propose on selecting the foundation of two main piers of the bridge,and analyzes and evaluates the three design schemes of bridge piers foundation.By comprehensive investigation,this paper finally validates west pier foundation locates in the range of K19＋224~K19＋254（weak karst development area and non-karst area） and east piers foundation should be selected to putting into the hard sandstone stratum.