220kV高压变电所基础沉降事故分析及加固实践

Foundation Settlement Incidents of a 220kV Substation and Foundation Reinforcement

分析了某高压变电所基础沉降的工程事故原因,以及带电运行的高压变电所实施地基基础加固的特殊性。针对高压变电所特殊的施工条件、严格的安全限制,提出了水泥压密注浆和微型钢管桩2种加固的方案。通过现场施工实践及静载试验,证明在该变电所特殊的施工环境中,采用微型钢管桩加固沉降基础,并施加一定的预应力,具有施工方法简单、传力可靠、对原基础扰动小、能够有效克服基础沉降的明显效果。

Causes of a 220 kV substation foundation settlement are analyzed, and the difficulties of foundation reinforcement in hot-line work substation are probed in. Two foundation reinforce- ment schemes are compared in detail, i.e. to retard foundation settlement attaching prestress miniature steel-tube pile and to strengthen compressive capacity of foundation soil by pressure casting cement paste. Field experimental research testifies that the former scheme is more feasi- ble. It operates more easily, transfers load more reliably, disturbs the original foundation less in the course of construction and reduces foundations settlement more effectively.