排桩模型在"嵌岩"基坑工程中的应用

排桩支护方案应用于存在上覆软弱土层的"嵌岩"基坑中,通常面临"吊脚桩"问题,其设计计算在规范中无明确设计方法或计算模型。根据分步开挖工况不同,拟合工程实际,采取多种模型设计方法,最大限度地利用岩土体自身强度,分别以排桩模型、"吊脚桩"模型、复合土钉墙模型,等效荷载替代桩锚土体模型等多种计算方法综合确定设计参数。以清晰明了的数学模型确保设计结果的可靠性,使设计方案做到安全可靠、经济合理、方便可行。

Application of Pile-row Model in Engineering of Foundafion Pit Embedded in Rock

Pile-row supporting scheme can be applied in foundation pit embedded in rock stratum overlain by soft soil stratum,but in practice,one might come across a so-called "suspended-pile" problem,i.e.The pile ends might not reach the pit bottom.At the present,no standard can be referred,specifying the design method or calculation model for solving it.In the artical,various models and design methods are suggested not only to determine the related design parameters corresponding to different steps of the excavation work and suitable for the engineering practice,but also to make good use of the surrounding rock or soil strength.Those mathematical models for the design,including the pile-row model,the suspended pile model,the compound soil-nail wall model,the model of equivalent load substituting for pile anchored into soil are seperately used to caculate for those dependent parameters,in order to ensure their good results for the safety,reliability,reasonableness in economy,convenience,and feasibility of engimeering design.