膨胀岩土地层盾构隧道管片结构荷载及内力特征

发布时间：2018-08-13 21:41

【摘要】：选取成都地铁2号线ZCK40+805.8隧道断面为目标断面,在管片上布设土压力盒、水压力计和混凝土应变计,对具有弱膨胀性的强—中风化泥岩地层盾构隧道施工过程中管片结构的荷载及内力特征进行跟踪测试。分析测试数据可知:脱环初期管片结构水压力变化较大,在管片拼装60环后,水压力开始缓慢增加,隧道贯通后的最终水压力低于理论静水压力;管片结构土压力的实测值小于理论值,它反映了注浆层、地层水土压力等因素对结构主体的共同作用;管片结构内力的稳定需要时间较长,最大内力值出现在隧道贯通后。管片结构内力的实测值与理论计算值的对比分析表明,在该地层中应用荷载—结构模型进行管片结构内力分析时,若采用水土合算方法计算荷载,无须考虑地层膨胀力的作用。
[Abstract]:The section of ZCK40 805.8 tunnel of Chengdu Metro Line 2 is selected as the target section, and the earth pressure box, water pressure gauge and concrete strain gauge are arranged on the segment. The load and internal force characteristics of the segment structure during the construction of the shield tunnel in the strong and medium weathered mudstone strata with weak dilatancy are tracked and tested. The analysis and test data show that the water pressure of the segment structure changes greatly at the initial stage of detorsion. After assembling 60 rings, the water pressure increases slowly, and the final water pressure after the tunnel is through is lower than the theoretical hydrostatic pressure. The measured value of soil pressure of segment structure is smaller than the theoretical value, which reflects the joint action of grouting layer and formation soil and water pressure on the main body of the structure, and the stabilization of the internal force of the segment structure takes a long time, and the maximum internal force value appears after the tunnel is through. The comparison and analysis of the measured values and the theoretical calculated values of the internal forces of the segment structure show that, when the load-structure model is applied to the analysis of the internal forces of the segment structures, if the load is calculated by the soil and water calculation method, the effect of the formation expansion force should not be considered.
【作者单位】：西南交通大学交通隧道工程教育部重点实验室;
【基金】：国家自然科学基金资助项目(51278422) 国家科技支撑计划课题(2012BAG05B03) 四川省青年科技基金资助项目(2012JQ0021) 中央高校专项资金资助项目(SWJTU11ZT33)
【分类号】：U455.43

【相似文献】