摘要
盾构穿越邻近桥梁桩基时通常采用隔离桩作为地基主动加固措施,但当隔离桩与既有桥梁桩基相距较近时,隔离桩桩基施工会对桥梁既有桩基产生影响,因此有必要对此进行分析。依托杭州地铁1号线下穿沪杭高铁余杭南站高架桥工程,结合现场实测数据对钻孔桩和旋喷桩施工引起既有高架桥桩基的变形进行分析。研究表明:钻孔桩施工对桩基水平位移影响很小,对沉降影响较大,现场实测最大沉降为0.94mm;钻孔桩完成后,旋喷桩施工对桩基水平位移和沉降有一定影响,现场实测桩顶最大水平位移为0.5mm,沉降为0.6mm。因此,在施工过程中应严格控制施工速度等参数,加强监测以减小隔离桩施工对既有高架桥桩基的影响。
The isolation pile is usually used as an active foundation strengthening measure when the shield machine passes through the adjacent bridge pile foundation. But when the isola- tion pile is too near to the pile foundation of an existing bridge, the construction of the foundation of the isolation pile is possible to influence the existing pile foundation. Therefore, it is necessary to analyze the influence of the construction of the isolation pile on the deformation of the adjacent pile foundation. On the basis of the project of the No. lline of the Hangzhou Subway which un- derpasses the Yuyao-Hangzhou South Station Viaduct and the measured data, the deformation of the pile foundation of the existing viaduct caused by the construction of the bored piles and the jet grouting piles was analyzed. The results of the analysis show that the construction of the bored piles has little influence on the horizontal displacement of the pile foundation, hut greatly influ- ences the settlement of the pile foundation, the maximum settlement amount measured in the field is 0.94 mm; conversely, after the completion of the bored pile construction, the construction of the jet grouting pile has some influence on the horizontal displacement and settlement of the pile foundation, the measured maximum horizontal displalement amount on the pile top is 0.5 mm, the settlement amount is 0.6 mm. Thus, in the construction process, the parameter such as construction speed should be strictly controlled and rigid monitoring work should be done to reduce the influence of the isolation piles on the pile foundation of the existing high speed railway bridge.
出处
《世界桥梁》
北大核心
2012年第5期54-58,共5页
World Bridges
关键词
高速铁路
高架桥
地基加固
隔离桩
high speed railway
viaduct
foundation strengthening
isolation pile
