复杂采空区地铁地基方案确定关键问题研究

Study on the key problems in Metro foundation design in complex goaf area

本文在查明采空区的坍塌历史、回填情况及加固处理程度的基础上,采用理论分析和数值模拟等方法,对深宽复杂采空区的塌陷发展趋势进行了预测,对不同工况下采空区的侧壁稳定性进行了深入的计算分析。同时在分析充填物物理力学特性、侧壁基岩物性及稳定性对不同地基方案的设计和施工影响后,提出了再次注浆处理采空区回填土体、优先采用地下梁+桩基方案穿越采空区的地基方案。并根据不同桩径、桩长的变形特性分析结果,综合考虑设计施工条件,提出了最优桩基方案。

On the basis of ascertaining the collapse history,backfilling and reinforcement of the goaf,the collapse development trend of deep and wide complicated goaf is predicted by means of theoretical analysis and numerical simulation,and the sidewall stability of goaf under different working conditions is calculated and analyzed.After analyzing the physical and mechanical properties of backfill material,the lithology and stability of surrounding rock on the design and construction under different foundation schemes,the foundation scheme of re-grouting the backfill soil and underground beam plus pile preferentially is put forward.Based on the analysis of the deformation characteristics of different pile diameters and lengths,an optimal pile scheme is proposed considering the design and construction conditions.