超大直径盾构隧道近接穿越条件下克泥效工法对土体及既有结构变形特性影响的研究  

Study on Infl uence of Clay Shock Method on Deformation Characteristics of Soil and Existing Structure Under Condition of Closely Crossing of Super Large Diameter Shield Tunnel

作　　者：杨成龙 YANG Chenglong(Shanghai Foundation Engineering Group Co.,Ltd.,Shanghai 200002,China)

机构地区：[1]上海市基础工程集团有限公司,上海200002

出　　处：《建筑施工》2022年第6期1323-1329,共7页Building Construction

摘　　要：超大直径盾构隧道近接穿越施工时,盾体通过阶段上覆土体变形规律及上覆既有建(构)筑物变形控制是目前地下交通工程建设中亟待解决的关键科学问题。采用现场原位监测,揭示了盾体环向间隙克泥效压注对盾构施工影响范围内土体变形的影响规律;结合上海北横通道新建工程Ⅶ标段15.56 m级超大直径盾构隧道近接穿越地铁10号线工程实例,对克泥效工法的上覆建(构)筑物沉降控制效果进行了分析。结果表明:在砂质粉土层中进行盾构法施工时,压注克泥效可有效减小盾体通过阶段地表位移量及地表沉降速率,同时可辅助减小地表工后总位移量;盾体通过阶段地表位移量、地表沉降速率及地表工后总位移量与克泥效压注量近似呈线性负相关;在盾构近接下穿既有隧道施工时,采用克泥效工法可显著提高盾体上方建(构)筑物的隆起量,使建(构)筑物变形控制在-20~+20 mm范围内。以上研究结果有助于推进超大直径盾构隧道近接穿越施工对地表及上覆建(构)筑物变形影响的定量研究,为沿海软土地区相似工况条件下克泥效工法的应用提供依据。During the closely crossing construction of super large diameter shield tunnel,the deformation law of the overlying soil and the deformation control of the overlying existing buildings(structures)are the key scientific problems to be solved in the construction of underground transportation engineering.Through in-situ monitoring,the influence law of shield circumferential clearance on soil deformation within the influence range of shield construction is revealed;combined with the engineering example of 15.56 m super large diameter shield tunnel close to Metro Line 10 in Bid Section VII of the new construction project of Shanghai North Cross Passage,the settlement control effect of overlying buildings(structures)by clay efficiency method is analyzed.The results show that,when shield construction is carried out in sandy silt layer,the pressure mud injection effect can effectively reduce the surface displacement and surface settlement rate during the shield passing stage,and can assist in reducing the total surface displacement after construction;the surface displacement,surface subsidence rate and total surface displacement after construction are approximately linearly and negatively correlated with the mud pressure injection;when the shield is close to and under the existing tunnel,the clay shock method can significantly improve the uplift of buildings(structures)above the shield and control the deformation of buildings(structures)within the range of-20~+20 mm.The above research results are helpful to promote the quantitative research on the influence of the proximity crossing construction of super large diameter shield tunnel on the deformation of the surface and overlying buildings(structures),and provide a basis for the application of clay shock method under similar working conditions in coastal soft soil areas.

关 键 词：超大直径隧道 盾构法施工 克泥效工法 变形特性 

分 类 号：TU998[建筑科学—市政工程]