海底取水盾构隧道管片力学性状的数值研究

Numerical analysis of mechanical behaviors of segments of subsea shield tunnel for water intake

为了研究海底取水隧道管片在施工和运行过程中力学性状的不同,采用三维实体模型对国内首次采用八环错缝拼装的三门核电取水隧道标准段进行分析.模型中管片采用实体单元模拟,螺栓采用梁单元模拟,充分考虑各接缝间的接触作用.计算结果表明,与施工阶段相比,运行期整体直径变形增大了1.5倍,最大正弯矩增大了44.4%,环向螺栓受力增大了近11倍,各接缝张开量增大了近9倍.八环错缝拼装时,关键块位置的改变将在一定程度上影响各环的内力分布,运行期各环拱顶处正弯矩最大值是最小值的2.22倍.对于取水隧道而言,运行期充水工况是控制工况.

A three-dimensional solid model was adopted to analyze the standard segment of Sanmen nuclear power station＇s water intake tunnel which was staggered joint assembling per eight rings in order to analyze the different mechanical behaviors of subsea water intake tunnel＇s segments between construction and operation.The segments were modeled by solid elements,the bolts were modeled by beam elements,and the contact role of joints was considered.The numerical results indicated that the diameter deformation of water intake tunnel in operation was 1.5 times larger than in construction,with the maximum positive moment increasing 44.4%,the internal force of circumferential bolt rising nearly 11 times,and the splaying amount of joints soaring up to nearly 9 times.When tunnel was staggered joint assembling per eight rings,key block＇s location would affect the distribution of internal force of segments.During the operation period,the maximum of positive moment of crown was 2.22 times larger than the minimum.For the water intake tunnel,operation with water stress is design control load case.