土体压力对地铁旁通道解冻后地表沉降的影响

The effect of earth pressure on ground settlement after frozen soil thawing in connect aisle construction of metro engineering

在地铁旁通道人工冻土解冻后,冻土体的融化沉降量不仅和土体性质、含水量有关,更受到周围土压力的影响,产生较大的压缩沉降,进而引起地表的沉降。结合随机介质理论方法和前苏联一维融土层沉降公式,建立了能够同时反映土体压力和融沉系数对地表沉降量影响的计算模型。结合某旁通道冻结工程,预测分析了无注浆条件下地表的沉降量。计算结果表明:对于旁通道冻结工程,土体解冻后的融沉量要小于土体压力产生的压缩变形量,其中压缩变形量约占总变形量的72%～87%。并且在土体埋深的增加或者地表有附加荷载的条件下,压缩变量所占比重将更大。

The thawing settlement of frozen soils in metro connect aisle not only relate with its property and water content but also the earth pressure which could make thawed soil engender large compressed settlement,then the ground settlement would take place.A mathematical model of ground settlement which include earth pressure and thaw-settlement coefficient was built by combining stochastic media theory with one dimension settlement formulas of thaw soils（former Soviet Union）.The model was applied to a lateral artificial freezing engineering of connect aisle for predicting the ground settlement if there was not grouting.The results show that the compression settlement is approximately 72%～87% of all settlement and it is greater than thaw settlement.The proportion of compression settlement will increase with the buried depth of soils or there are additional loads acting on the ground surface.