深埋斜坡嵌岩桩基岩界面的形态预测与分析  

Shape Prediction and Analysis of Bedrock Interface for Deep Slope Rock-Socketed Pile

作　　者：葛嘉诚[1,2] 薛亚东[1,2] 方超[1,2] 

机构地区：[1]同济大学岩土及地下工程教育部重点实验室,上海200092 [2]同济大学地下建筑与工程系,上海200092

出　　处：《地下空间与工程学报》2013年第S1期1587-1593,共7页Chinese Journal of Underground Space and Engineering

基　　金：国家自然科学基金项目(40772179;41072206);贵州省交通运输厅科技项目(2010-122-010)

摘　　要：峡谷区域的地层,地质属性变异强烈,空间分布复杂。此条件下的嵌岩桩通常在斜坡基岩体中承载,其稳定性与承载性能受到基岩界面坡角的影响。传统地质勘查提供的工程地质剖面图受人工干预具有较大的随机性,并且无法为此类斜坡嵌岩桩提供充分的界面坡角设计参数。本文结合贵州某桥梁工程场地的钻孔勘察数据,采用克里格方法,通过变差函数分析了基岩埋深的空间变异规律;根据插值估计结果获得了较为直观有效的三维基岩界面形态预测图,以及工程场地内112根嵌岩桩对应的基岩界面坡度,得出需重点考虑斜坡基岩体影响的桩基分布范围。针对峡谷区域地层参数具有V型漂移趋势问题,通过选定合适的有效滞后距以限定准平稳带的范围,获得了较好的变差函数与预测效果。本文的研究成果,对深覆盖层嵌岩桩的承载力计算与施工设计具有较好的指导意义。Stratum in gorge area has strong variability in geological properties. When the pile is socketed in bedrock with a sloped interface,the stability and bearing capacity of pile will be largely influenced by the slope angle.Traditional geological section by geological survey is with randomness due to manual intervention,and lack of reliable basis for the pile design and construction. The authors applied Kriging method to drilling investigation data of a bridge site in Guizhou,and obtained the variogram model of elevation of bedrock interface. Based on estimation result,the authors acquired a 3-D figure of bedrock interface,and slope angles of bedrock interface corresponding to 112 piles.The extent of influenced piles can be evaluated. Especially,the parameter of stratum in gorge zone generally has a Vshape drifting tendency,thus a suitable active lag distance is selected to confine the radius of quasi-stationary area. It has helped to get a better regression of variogram model and higher estimation precision. It is proved in practice that the result is beneficial to the project during designing and construction.

关 键 词：斜坡嵌岩桩 空间变异 克里格方法 基岩界面形态 

分 类 号：TU473.1[建筑科学—结构工程] TU45[建筑科学—土工工程]