排水固结法处理机场场道地基预压荷载取值研究

Study on value-selection in preloading of airport subsoil with taking consolidation by dewatering into account

当采用排水固结预压法处理机场场道时，需要确定场道的预压荷载，而相关规范对场道预压荷载的取值未作明确的规定。本文分析了机场场道地基处理后的地基结构和荷载类型，采用布辛奈斯克法和有限元法计算了当今最大飞行器空客A380造成的地基附加应力。分析结果表明：两种方法计算的地基附加应力基本相符；软基泥面以上填土厚度越小，上部荷载在泥面产生的附加应力越大；在选择机场场道预压荷载时，考虑可靠度、最不利工况等因素，应适当提高预压荷载；厦门新机场地基处理一期工程泥面以上填土厚度2．0—2．5m，建议场道地基处理设计时预压荷载取80kPa，相当于预压土（砂）5．0m；在填土厚度较厚的区域，可适当减小预压荷栽。

When handling the airport runway with drainage consolidation preloading method,we need to determine the pre-load and the value of runway pre-load in relevant specification are not clear. This paper analyzed foundation structure and load type after airport runway foundation treatment and calculated the foundation additional stress caused by the largest aircraft airbus A380 with Boussinesq method and finite element method. The analysis results showed that the foundation additional stress are similar calculated by these two methods, additional stress of mud surface produced by upper load is larger when filling thickness above the soft mud is smaller,when selecting airport runway pre-load,we should consider the factors such as the reliability,the most unfavorable conditions and increase the pre-load properly. The soil filling thickness above the mud surface of Xiamen new airport ground treatment 1st project is 2.0 2.5 m,this paper suggests the pre-load is 80 kPa during airport runway ground treatment design,which is equivalent to the preloading soil （sand） of 5.0 m, and the pre-load should be reduced appropriately in thick filling area.