地基液化作用下地下异形断面结构变形规律研究OA

In order to study the deformation law of underground irregular cross-section structures under the action of foundation liquefaction,numerical simulation methods were used to investigate the deformation response charac-teristics under the action of foundation liquefaction based on the underground irregular cross-section structure of Xiong'an Xiaoli Station of the Xiongan-Xinzhou High-speed Railway.The research results show that:1)Under earthquake action,the peak pore pressure ratio of the ③1 fine sand layer in easily liquefiable strata reaches 0.851(＜1),while the peak pore pressure ratios of the ④2 fine sand layer and the ⑤1 fine sand layer are 0.132 and 0.326,respectively(both＜1).According to the liquefaction discrimination criteria,it can be determined that the ③1 fine sand layer has undergone liquefaction,while the ④2 fine sand layer and the ⑤1 fine sand layer have not undergone liquefaction.2)Under earthquake action,the maximum displacement value of the outer side of the underground structure bottom plate reaches 28.12 mm,significantly greater than the inner side's 2.43 mm,indicating that the anti floating piles set on the inner side of the underground structure bottom plate effectively limite the vertical dis-placement of the structure and play a good synergistic effect of anti floating and seismic resistance.At the same time,the maximum displacement difference at the irregular section of the structure is less than 2 mm,indicating that the special section design has good deformation coordination ability and without structural damage.3)Under earthquake action,the vertical stress of the structural bottom plate reaches the maximum value of 9.03 MPa at the inflection point of the irregular section,showing a significant stress concentration phenomenon.The majority of the lateral stress on the structural bottom plate is compressive stress,which are less than 200 kPa and meet the stability requirements of concrete compressive strength,without the occurrence of compressive failure.