某基坑工程施工全过程条件下上水管道沉降的变化规律分析

Analysis of the Variation Law of the Water-Pipe Settlement During the Whole Construction Process of a Foundation Pit Engineering

虽于上海地区某基坑工程施工全过程上水管线监测数据,对上水管线的沉降变化趋势进行分析,并与相邻地表沉降监测数据进行对比:分析发现,基坑开挖阶段管线沉降速率最大;离基坑越近,管线沉降速率越大;围护结构加固对管线沉降起一定的缓冲作用。管线沉降与邻近的地表沉降变化趋势基本一致,采用沉降传递系数并利用地表沉降数据估算相应位置的管线沉降计算值与实测值相比,在非开挖阶段基本吻合,而在开挖阶段则偏大,这说明利用计算值可提早预警,对风险控制有利。因此,在实际监测工作中,可以利用沉降传递系数法适当减小监测工作量或弥补管线监测点不足的情况。

Based on the whole measured settlement data across the whole construction process of one foundation pit engineering in Shanghai,the change of the water-pipe settlement was analyzed and compared with adjacent surface settlement.Some results can be concluded that the largest displacement rate appeared in the excavation stage among the whole construction process and the clearer between the water-pipe and the foundation pit,the larger the displacement rate.Retaining structure reinforcement exerts certain buffer effect on pipeline settlement.The vertical displacement of water pipe and adjacent surface monitoring spots shared the same trend across the whole construction process.Calculated values for water pipe settlement according to settlement transmission method conformed well to the measured data in non-excavation stages and became larger compared to measured data during excavation stage,which implies that it is benefit to use calculated value for early warning from the perspective of risk management.Therefore,settlement transmission method can be adopted in practical monitoring work to reduce the workload or make up for the insufficient of pipeline monitoring.