疏排水沉降地层高性能混杂纤维混凝土井壁受力特征

Mechanical characteristics of high-performance hybrid fiber concrete shaft lining in drainage settlement ground

为解决深厚表土层中混凝土井壁支护难题,采用ANSYS有限元软件对比分析混杂纤维高强度混凝土井壁和普通高强度混凝土井壁在表土层厚度200~600 m范围变化时的变形和受力情况。计算结果表明:2种井壁在同等受力情况下,混杂纤维混凝土井壁应变大于普通混凝土,掺杂纤维可以改善井壁脆性;井壁受到的最大环向应力随着表土层厚度增大而增大,且沿着井壁径向由外到内逐渐增大,环向应变始终是压应变且内表面大于外表面;随着埋深增加,井壁变形从以轴向变形为主变成以径向变形为主;最后给出应力应变与表土层厚度之间关系的回归公式,可指导工程实际。

In order to solve the problem of concrete shaft support in deep topsoil layer,ANSYS finite element software was used to compare and analyze the deformation and stress of hybrid fiber high-strength concrete shaft and ordinary high-strength concrete shaft when the thickness of topsoil layer varied from 200 m to 600 m.The calculation results show that:the strain of mixed fiber concrete shaft is greater than that of ordinary concrete shaft under the same stress,and the fiber can improve the brittleness of shaft;the maximum circumferential stress on shaft increases with the increase of topsoil layer thickness,and increases gradually from outside to inside along the shaft radial direction,and the circumferential strain is always compressive strain and the inner surface is greater than the outer surface.As the burial depth increases,the deformation of shaft changes from mainly axial deformation to mainly radial deformation;finally,the regression equation of the relationship between stress-strain and thickness of topsoil layer is given,which can guide the engineering practice.