张靖皋长江大桥锚碇基础地下连续墙施工技术

张靖皋长江大桥起自如皋市石庄镇焦庄村东侧，上跨S336，经石庄工业园东北、如皋港东升石材产业园东侧，路线转向南偏东，后于如皋华泰重工厂区架桥，采用主跨1 208 m双塔悬索桥跨越福北水道，进入如皋中汊。该悬索桥南锚碇位于长江江心岛上，基础采用圆形地下连续墙结构。地下水位受长江水潮汐影响明显，时刻不断地随潮位变化，下水位峰值较长江水位滞后约1～1.5 h，对地下连续墙施工影响较大，如何控制成槽及清孔质量、钢筋笼吊装是施工成功的关键。同时，成槽泥浆处理也是制约整个项目的关键工序。通过介绍张靖皋长江大桥工程概况、地下连续墙施工、泥浆处理和质量通病预防措施，并对地下连续墙槽段进行超声波检测。结果表明，所有墙体和接缝质量良好，均为Ⅰ类桩。

Construction Technology of Underground Diaphragm Wall for Anchorage Foundation of Zhangjinggao Yangtze River Bridge

Zhangjinggao Yangtze River Bridge starts from the east side of Jiaozhuang Village in Shizhuang Town in Rugao, spans S336, passes through the northeast of Shizhuang Industrial Park and the east side of Dongsheng Stone Industrial Park of Rugao Port and turns south by east. And then the bridge is built in the plant area of Rugao Huatai Heavy Industry. The main span of the bridge is 1 208 m double-pylon suspension bridge, which spans Fubei Waterway and enters the middle branch of Rugao. The south anchorage of the suspension bridge is located on the island in the middle of the Yangtze River, and its foundation is a circular underground diaphragm wall structure. The underground water level is obviously affected by the water tide of the Yangtze River and constantly changes with the tide level. The peak value of the underground water level lags behind the water level of the Yangtze River by about 1~1.5 h, which has a great impact on the construction of underground diaphragm wall. How to control the quality of slotting and hole cleaning, and how to hoist the reinforcement cage are the keys to successful construction. Also, the treatment of slotting slurry is a key process that restricts the whole project. The engineering situation of Zhangjianggao Yangtze River Bridge, construction of underground diaphragm wall, treatment of mud and preventive measures of common quality problems are introduced, and the ultrasonic testing is carried out for slotting section of underground diaphragm wall. The result shows that all qualities of wall and joint are good, and the piles are all Class I.