运行变电站打桩加固沉降基础的应用

Study on Application of Piling to Reinforce Settled Foundation at Substation under Operation

结合连云港海淤地质条件下的某220kV变电站设备基础沉降问题,在限制安全高度2.2m、不停电的要求下,研制小型打桩机,进行了微型钢管桩加固试验应用研究。研究表明:所研制的小型打桩机能够在运行变电站的限高空间下作业,突破了运行变电站不便进行基础打桩加固的禁区;所打微型钢管桩能够有效阻止独立基础沉降;桩顶施加预应力的"先顶后焊"技术,能够明显提高加固效果。

Combining with equipment foundation settlement at a certain 220 kV substation in sea silt ground in Lianyungang, a small-scale pile driver was developed and the strengthening tests by small-scale steel pipe pile were carried out under the requirements of 2.2 m high limitation and without power-off. The results showed that the driver works well and it is a breakthrough for the foundation reinforcement of substation under operation. Meanwhile, the driven micro-steel pipe pile can effectively stop the independent foundation settlement, and ＂welding after pressing＂ prestress technology on the pile top can improve the reinforcing effect obviously.