不同地基加固工艺对周边环境变形影响分析

Analysis of soil disturbance for different ground improvement methods

当施工场地周边环境较为复杂时,如邻近既有地铁盾构隧道或浅基础老旧建筑,地基加固对周边环境变形的影响应严格控制。结合现场监测数据和数值分析结果,对渠式切割水泥土地下连续墙(TRD)、全方位高压旋喷桩(MJS)和三轴水泥搅拌桩(SMW)等地基加固工艺对周边环境变形的影响规律进行了分析。3种工艺对周边环境变形的影响均可控制在毫米级,综合考虑其他因素后适用于对应复杂环境条件下的地基加固。研究结果显示周边土体变形随与加固位置的距离增大而变小,并可通过调整施工参数来减小。周边环境变形还与被加固土层性质、加固设备自重和机动性等因素有关。杭州地铁的多项工程已证实TRD和MJS对周边环境变形的影响较小。

When the surrounding environment of the construction site is relatively complex,such as adjacent to existing subway shield tunnels or old buildings with shallow foundations,the impact of ground improvement on the surrounding environment deformation should be strictly controlled.Combined with field monitoring data and numerical analysis results,the effects of ground improvement methods on the soil deformation to surrounding environment are analyzed,such as trench cutting re-mixing deep wall method(TRD),metro jet system pile method(MJS)and soil mixing wall(SMW).The effect of the three methods on the soil deformation of surrounding environment can be controlled at the millimeter level,which is suitable for ground improvement under complex environmental conditions.The research results show that the surrounding soil deformation decreases with the increase of the distance from the reinforcement location,and can be reduced by adjusting the construction parameters.The soil deformation of surrounding environment is also related to factors such as soil properties,the weight and mobility of the equipment.A number of subway projects in Hangzhou have confirmed that TRD and MJS have little impact on the soil deformation to the surrounding environment.