泥水盾构穿越堤坝沉降控制研究

Study on Settlement Control for Slurry Shields Crossing the Embankment

对杭州庆春路过江盾构隧道施工引起的大堤沉降实测数据进行了分析,采用Peck公式对横向沉降曲线进行拟合,并对东西线隧道上方大堤沉降进行了对比。分析结果表明:西线盾构施工引起的大堤沉降比东线要大,原因是西线盾构穿堤期间持续降雨、泥浆管爆裂引起泥水压力剧烈波动,以及首次穿堤缺少工程经验、盾构掘进参数控制劣于东线等;验证了Peck公式在本工程中的适用性,其中西线隧道上方大堤沉降槽宽度参数K取值范围为0.325～0.471,地层损失率η取值范围为0.990%～1.570%,东线隧道上方大堤沉降槽宽度参数K取值范围为0.240～0.338,地层损失率η取值范围为0.252%～0.515%;结合工程实践,提出了泥水平衡盾构穿越堤坝控制沉降的措施。

Based on the field settlement monitoring data in the construction of Hangzhou Qingchun Road river-crossing tunnel,settlements of the embankment induced by two shields respectively were compared.Results showed that the settlements of the embankment induced by the shield on west line were larger than those on east line,which was due to sustained rainfall,severe fluctuation of chamber pressures,lack of construction experience and worse control of shielding parameters on the west line.Peck equation＇s applicability was evaluated,and the value range of the transverse settlement tough-width parameters and the soil loss ratio in this project were suggested.Considering the successful experience of crossing the embankment by these tunnels,some practical and effective measures are suggested for slurry shield to traverse the embankment.These results would provide a scientific basis for the design and construction of similar shield tunnels.