南水北调中线北京段西四环暗涵衬砌结构受力特点研究

Analysis on the mechanical characteristics of lining structure of the Beijing’s West Fourth Ring Road of the Middle Route of the South-to-North Water Diversion Project based on monitoring data

南水北调中线北京段西四环暗涵埋设了土压力计和钢筋应力计等观测设备,用于连续观测施工期和运行期相关情况。根据暗涵2011年10月至2012年3月期间通水测试的监测数据,以3个典型断面为研究对象,重点研究和分析了结构内力分配机制。研究表明,暗涵的衬砌结构为联合受力结构,一衬和二衬共同承担内水压力,一二衬之间的回填灌浆改善了二衬的受力状态,一二衬协同变形得到优化。另外,衬砌结构的内力增量监测值与结构力学法的计算值较为接近,暗涵设计安全系数高,西四环暗涵结构安全。

Earth pressure gauge and steel bar stress gauge have been installed in the West Fourth Ring culvert of Beijing section of the middle route of South-to-North Water Diversion Project,which can be used for continuous observation of relevant conditions during construction period and operation period.According to the monitoring data of the open water test of the implied culvert from October 2011 to March 2012,the internal force distribution mechanism of the structure is studied and analyzed with three typical sections as the research object.The results show that the lining structure of the culvert is a combined force structure.The first and second linings bear the internal water pressure together.The backfilling grouting between the first and second linings improves the stress state of the second lining,and the coordinated deformation of the first and second linings is optimized.In addition,the monitoring value of internal force increment of lining structure is closed to the calculated value of structural mechanics method.The design safety factor of hidden culvert is high,and the structure of the West Fourth Ring hidden culvert is safe.