采煤回填区域下湿陷性黄土地基处理技术研究

Study on treatment technology of collapsible loess foundation in coal mining mackfill area

为探明采煤回填区条件下灰土挤密法对湿陷性黄土地基的处理效果,以榆林市府谷县内农光互补项目升压站地基处理为例,通过现场和室内相结合的方法开展复合地基静载试验和探井试验,分析了灰土挤密施工工艺对采煤回填区地基承载力和湿陷性的影响。结果表明:灰土挤密技术有效增大了地基强度、提升地基承载力,消除了桩间土土壤湿陷性、提升了地基土壤密实度,处理后的地基土壤湿陷性系数(0.001~0.010)远小于湿陷性界值(0.015),土壤压缩系数(0.08~0.15)远小于初始值(0.50~0.65)。受湿陷性黄土自身特性的限制,建议在后期施工时采取严格的防水措施,防止地基浸水后对上层建筑物造成不良影响。研究结果可为采煤回填区湿陷性黄土地区的工程地基处理提供技术参考。

In order to explore the effect of ash soil extrusion method on collapsible loess foundation treatment under the conditions of coal mining backfill area,taking the booster station foundation treatment of the agro-solar complementary project in Fugu County of Yulin City as an example,and the influence of the ash soil extrusion construction process on the bearing capacity and collapsibility of the foundation in the coal mining backfill area is analyzed by combining on-site and indoor methods to conduct static load tests and exploratory well tests on composite foundations.The results show that the ash soil extrusion technology effectively increase the foundation strength,improve the bearing capacity of the foundation,eliminate the soil collapsibility between piles,and improve the soil compactness of the foundation.The collapsibility coefficient of the treated foundation soil(0.001~0.010)is much less than the collapsibility critical value(0.015),and the soil compression coefficient(0.08~0.15)is much smaller than the initial value(0.50~0.65).It is recommended to take strict waterproof measures during later construction to prevent adverse effects on the superstructure after the foundation is soaked in water due to the limitations of the inherent characteristics of collapsible loess.The research results can provide a technical reference for the engineering foundation treatment in collapsible loess areas of coal mining backfill areas.