互层组合膨胀岩土地基中隧道对临近管线作用及致灾机理研究

In actual engineering, the construction and operation of tunnels have significant effects on the adjacent pipeline. However, there is little consideration on layered characteristic of strata, influence of climate and long term influence of cyclic loading in recent research. Rely on the line 1 of Nanning subway and base on the interbedding combination characteristic of expansive soil foundation, the large-scale laboratory model test, centrifuge experiment, numerical simulation will be applied in this project. And the disaster-causing mechanism and effects on adjacent pipeline from construction and operation of tunnels will be studied, including the engineering characteristic and settlement law of expansive soils under extreme climate, the interaction mechanism of tunnel - soil - pipeline system of tunnel excavation under extreme climate, the prediction of adjacent pipeline's settlement and disaster-causing mechanism under long term reciprocating traffic loads.The application of this research results is expected to accurately predict the effects to the adjacent pipeline from the construction and operation of tunnels in expansive soil zone, and some corresponding measures will be taken. Furthermore, this research is hopefully to provide essential theorectical supports for the disaster prevention and control in design, construction and operation of subway in expansive soil zone.

针对隧道建设及运营对相邻管线有明显影响的工程实际及目前相关研究存在"忽略地层的分层特性"、"忽略气候因素的影响"和"忽略往复运营荷载的长期影响"等不足，本课题拟以南宁地铁1#线为依托，针对膨胀岩土地基互层组合特性，分别采用大型室内模型试验、离心模型实验、数值模拟等多种研究手段，系统研究互层组合膨胀岩土地基中隧道建设及运营对临近管线作用及致灾机理。主要包括：极端气候下互层组合地层中膨胀岩土的工程特性及沉降规律；极端气候下互层组合膨胀岩土地基中隧道开挖时隧道-岩土-管线相互作用机理；互层组合膨胀岩土地基中往复运营荷载下临近隧道的管线长期沉降及致灾机理。该项目的实施可更为准确地预测膨胀土区域隧道建设及运营对现有管线的影响，进而有效评估现有管线的工作性能，并采取针对性的治理措施，从而为维护现有管线的安全与正常工作提供理论依据，并对膨胀土区域地铁的设计、施工及运营中的灾害防治，具有重要现实指导意义。

针对隧道建设及运营对相邻管线有明显影响的工程实际及目前相关研究存在“忽略地层的分层特性”、“忽略气候因素的影响”和“忽略往复运营荷载的长期影响”等不足，本课题以南宁地铁1#线为依托，针对膨胀岩土地基互层组合特性，分别采用室内模型试验、三维离心模型试验、数值模拟、理论分析等研究手段，系统研究了互层组合膨胀岩土地基中隧道建设和运营对临近管线作用及致灾机理。得到以下成果：不同埋深盾构双隧道开挖对既有管线影响的三维离心模型试验成果；盾构双隧道不同开挖顺序及不同布置形式对既有管线影响的三维离心模型试验成果；盾构双隧道开挖对连续管线影响的预测分析成果；盾构双隧道开挖对节点管线影响的预测分析成果；管-隧平行及垂直布置时盾构隧道开挖对临近地埋管线影响的研究成果；盾构隧道施工参数对既有地埋管线影响的研究成果；地铁运营荷载作用下粉砂层动力特性试验研究成果。该项目的实施可为更准确地预测膨胀土区域隧道建设及运营对现有管线的影响，进而有效评估现有管线的工作性能，并采取针对性的治理措施，从而为维护现有管线的安全与正常工作提供理论依据，并对膨胀土区域地铁的设计、施工及运营中的灾害防治，具有重要现实指导意义。