昆明新机场航站区下伏溶洞地基承载力分析

The Carrying Capacity Analysis of Kunming New Airport Terminal Area Underlying Cave Foundation

溶洞地基承载力的影响因素众多。溶洞埋深、溶洞直径(跨度)、水平相邻溶洞的间距,竖向相邻溶洞的间距及溶洞断面形态等对地基的承载力影响很大。应用工程地质分析和数值模拟相结合的方法,对昆明新机场下伏溶洞地基承载力进行了分析,得出当单个溶洞埋深大于2倍直径后,上部荷载与下部溶蚀空间的关系较小。当水平相邻溶洞的间距大于1倍跨度以及当竖向相邻溶洞间距大于0.5倍跨度后,可以忽略溶洞对上部荷载的影响。溶蚀率每增加5%,上部最大荷载q_(max)降低幅度约6%～10%。当跨度大于3倍洞高时,上部最大荷载的降低幅度相对较小,竖向型溶洞所能承受的荷载相对较大。

There are many factors that affect bearing capacity of Cave foundation, such as Cave depth, the caves diameter （span）, spacing vertically adjacent caves and caverns section form the foundation bearing capacity. The way, combined engineering geology analysis with numerical simulation, was applied to analyze the underlying bearing capacity of Cave foundation. According to this way, it concludes that the relationship between the diameter of the upper load and the lower part of the dissolution is smaller when a single cave depth is greater than 2 times, and the impaction of the cave to the top load can be ignored when the spacing of the level of the adjacent cave is greater than one times and the vertical distance is greater than 0. 5 times of the span. Besides, the upper part of the maximum load qmax decrease about 6% to 10% from each additional 5% of dissolution rate. When the span is greater than three times of the hole high, the decrease range of the maximum load on the top of foundation is relatively small; on the contrary, the load that vertical type caves can withstand is relatively large.