卤水井开采对铁路桥梁群桩的影响分析

发布时间：2018-01-30 14:12

本文关键词： 卤水井开采群桩沉降轴力摩阻力铁路桥数值模拟　出处：《中国铁道科学》2017年04期 　论文类型：期刊论文

【摘要】：为研究卤水井开采对德州—大家洼铁路沿线桥梁安全性的影响,在现场监测数据的基础上,采用有限差分软件FLAC3D建立多口卤水井开采条件下带承台群桩的三维计算模型,分析井内不同地下水位降时的桩土沉降特性及各单桩的内力分布规律。结果表明:随着地下水位的下降,地面沉降范围逐渐增大且呈漏斗状分布,沉降漏斗的中心位于群井的中心,地面沉降范围在距群井中心100m内;群桩沉降主要发生在地下水位从-9m下降至-33.1m的过程中,此阶段群桩沉降量占工后总沉量的64.7%;随着地下水位的下降,各桩的轴力沿桩身先增大后减小,桩身上部负摩阻力的作用区域逐渐增大,且负摩阻力沿桩身先增大后减小,各桩最大轴力所在截面和中性点不断下移;在相同的地下水位降条件下,各桩轴力和负摩阻力的大小顺序为角桩侧桩近井中桩中桩;抽水结束且群桩沉降达到稳定后,角桩桩底侧面受到的正摩阻力最大,为75kPa。
[Abstract]:In order to study the influence of brine well mining on the safety of bridges along the Dezhou-Dajiawa railway, the field monitoring data are used. In this paper, the finite difference software FLAC3D is used to set up the three-dimensional calculation model of pile group with cap under the condition of multiple brine wells. The characteristics of pile-soil settlement and the law of internal force distribution of each pile are analyzed when different groundwater levels fall in the well. The results show that with the decrease of groundwater level, the range of ground subsidence increases gradually and presents a funnel-shaped distribution. The center of the subsidence funnel is located in the center of the group well, and the land subsidence range is within 100 m from the center of the group well. The settlement of pile group mainly occurs in the process of the groundwater level falling from -9m to -33.1 m, and the settlement of pile group accounts for 64.7% of the total settlement after construction at this stage. With the decrease of groundwater level, the axial force of each pile first increases and then decreases along the pile body, and the negative frictional resistance increases gradually and then decreases along the pile body. The section and neutral point of the maximum axial force of each pile are continuously moving down; Under the same groundwater level drop condition, the order of axial force and negative friction resistance of each pile is angle pile side pile near well pile; At the end of pumping and stable settlement of pile group, the positive friction on the bottom side of the angular pile is the largest, which is 75 KPA.
【作者单位】：大连交通大学土木与安全工程学院;
【基金】：国家自然科学基金资助项目(51574055) 辽宁省自然科学基金资助项目(20170540143)
【分类号】：U443.15
【正文快照】： 铁路沿线区域性地面沉降严重削弱了铁路桥梁群桩基础的稳定性,使桥梁发生均匀或差异性沉降[1-3],过量开采卤水是造成德(德州)大(大家洼)铁路沿线区域性地面沉降的主要原因[4-6]。随着卤水水位的下降,土体骨架发生压缩变形并影响土体的渗透性能。目前,抽水对桥梁群桩沉降及内力

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