土工格栅二灰土加宽路基的力学特性

发布时间：2018-01-04 02:35

本文关键词：土工格栅二灰土加宽路基的力学特性　出处：《公路交通科技》2014年09期 　论文类型：期刊论文

【摘要】：以青岛—银川高速公路济南至青岛段某加宽段改扩建工程为依托,对土工格栅二灰土加宽路基施工力学特性进行对比分析,得出以下结论:(1)土工格栅与二灰改良土有效控制了路基竖向位移的发展,竖向位移以新、旧路基坡脚处为中心呈现近似弧形辐射衰减;(2)加筋材料摩擦效应有效抑制了路基填土的挤出变形,加筋后的路基填土的水平变形明显减小,有利于改善路基整体受力特性,路基水平位移受时间效应影响较小;(3)铺设土工格栅形成明显的网兜效应,路基填土塑性区的发展得到有效控制;(4)剪、压破坏塑性区主要集中在路基与旧路基结合的坡脚处,这与位移场计算结果相一致,在设计与施工中应予以关注;(5)加宽路基竣工后,水平位移先增大后减小表现出一定程度的非线性,宏观上表现为鼓状变形。土工格栅与二灰土改良有效控制新路基水平位移的发展并满足其稳定性要求,后期路基水平位移主要由土工格栅拉伸引起的。
[Abstract]:Based on the extension project of a widening section from Jinan to Qingdao section of Qingdao Yinchuan Expressway, this paper makes a comparative analysis on the construction mechanical characteristics of the soil widening roadbed in the geogrid. The following conclusions are drawn: (1) Geogrid and modified soil effectively control the development of subgrade vertical displacement, the vertical displacement takes on the new and the old roadbed slope foot as the center, and presents the approximate arc radiation attenuation; (2) the friction effect of reinforced material can effectively restrain the extrusion deformation of subgrade fill, and the horizontal deformation of reinforced subgrade fill is obviously reduced, which is helpful to improve the overall bearing characteristics of roadbed. The horizontal displacement of roadbed is less affected by time effect. (3) laying geogrid forms obvious netting effect, and the development of plastic zone of subgrade fill is effectively controlled; (4) the plastic zone of shear and compression failure is mainly concentrated at the foot of the slope where the roadbed is combined with the old subgrade, which is consistent with the result of the displacement field calculation and should be paid attention to in the design and construction. 5) after the widening of roadbed is completed, the horizontal displacement increases first and then decreases to a certain degree of nonlinearity. Macroscopically it is shown as drum deformation. The improvement of geogrid and two-lime soil can effectively control the development of the new roadbed horizontal displacement and meet its stability requirements. In the late stage the horizontal displacement of roadbed is mainly caused by geogrid tension.
【作者单位】：陕西铁路工程职业技术学院;北京交通大学土木与建筑工程学院;
【基金】：国家自然科学基金项目(51274079)
【分类号】：U416.1
【正文快照】： 0工程概况近年来,我国高速公路建设迎来了跨越式发展的新时期,已建成的高速公路的运营能力与日益增长的运量需求产生了越来越多的矛盾,对既有高速公路进行改扩建成为缓解交通压力的重要举措。相对于建设新线,既有高速公路改扩建工期较短,占地较少,有利于保护周边环境和满足经

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