矿区深水防渗河床上桥墩围堰施工技术

Construction Technology of Bridge Pier Cofferdam on Deep Water Impermeable Riverbed in MiningArea

针对矿区跨河桥梁采用围堰施工过程中河水下渗至矿井的风险,提出一种新型的防渗河床上桥墩围堰施工工法。通过采取水下板体结构绳锯切割施工工艺,结合锁扣钢管桩与拉森桩组合围堰技术,实现了基坑变形的有效控制;通过对拔除围护桩后的土体采用水泥黏土浆液进行填充密实,在保证河床防渗要求的同时,减少了对水体的污染。实践表明,矿区防渗河床上桥墩围堰施工工法安全性好、施工速度快、成本低,在类似工况下具有广泛的应用前景。

Aiming at the risk of river water seepage to mine shafts during the construction process of cross-river bridges in mining areas using cofferdams,a new construction method of cofferdam construction for bridge piers on impermeable riverbeds is proposed.By adopting the construction process of rope saw cutting of underwater plate structure,combined with the combination of locking steel pipe pile and Larsen pile cofferdam technology,the effective control of foundation pit deformation is realized;by filling the soil after the extraction of the cofferdam pile with cement-clay slurry for compactness,the pollution to the water body is reduced while ensuring the impermeability requirements of the riverbed.The practice shows that the construction method of bridge pier cofferdam on the seepage control riverbed in mining area is safe,fast and low cost,and has a wide application prospect in similar working conditions.