基于中风化岩面分布特征的桩长确定方法研究与应用——以合肥地铁4号线科学城车辆段为例

Study on Determination Method of Pile Length Based on Distribution Characteristics of Middle-weathered Rock Surface——Taking Hefei Metro Line 4 Science City Depot as an Example

地铁车辆段等大型场站建设过程中,桩基础应用广泛,而桩长的确定是一项重要的工作。本文结合合肥地铁4号线科学城车辆段岩土工程勘察成果,在定性及定量的确定中风化岩后,对该场地内中风化岩面埋深及标高进行统计,沿钻孔剖面线方向对中风化岩空间分布进行分析,结合Surfer软件绘制场地中风化岩面等值线分布图,量化整个场区范围内中风化岩面深度。结果表明:场地内中风化岩层连续广泛分布,沿钻孔剖面线由南至北向岩面埋深呈中间深两边浅的趋势,由西至东向中风化砂质泥岩埋深逐渐变浅。最后根据桩长计算公式和场地内中风化岩面等值线分布图,确定桩长。

The pile foundation is widely used in the construction of large-scale station such as metro vehicle depot,and the determination of pile length is an important task.In this paper,based on the results of geotechnical engineering investigation in Scientific City of Hefei Metro Line 4,and after qualitatively and quantitatively determining the weathering rock,statistics of middle-weathered rock buried depth and level elevation in the site are made,The spatial distribution of middle-weathered rock is analyzed along the borehole profile,and the contour map of weathered rock Surfer in the site is drawn with Surfer software,and the depth of middle-weathered rock Surfer in the whole field is quantified.The results show that the middle-weathered rock layers are distributed widely in the site.The burial depth of the rock face along the borehole profile line from south to north shows a shallow trend on both sides of the middle depth.The burial depth of weathered sandy mudstone gradually decreases from west to east.Finally,the pile length is determined according to the formula of pile length and the contour map of weathered rock surface in the site.