TEST OF FOUNDATION REINFORCEMENT OF OPERATIONAL SUBSTATION BY DEVELOPING SMALL-SCALE PILE DRIVER

The settlement of the foundation on the soft ground would affect the normal operation and safety of the substation. The existing reinforcing methods and machinery can't work in the high-voltage fields. For a 220kV substation on the sea sediment foundation in a city along the coast, Jiangsu Province, China, the settlement should be controlled at a 2.2m high security restrictions with the requirement of the original operation of the substation. A small-scale pile-driver was developed, and reinforcement tests were carried out. The results show that the small-scale pile driver can work well for running substation, which is a breakthrough of the reinforcement of substation foundation at the restricted space. The micro-steel pipe pile can effectively prevent the settlement of independent foundation.The technology of prestressing on the pile top, soldering after withstand, can improve reinforcement effect.