拓宽路基差异沉降控制技术模型试验研究  

Model tests on control techniques for differential settlement of road widening

作　　者：翁效林[1,2] 张留俊[2] 李林涛 郭永建[1] 

机构地区：[1]长安大学特殊地区公路工程教育部重点实验室,陕西西安710064 [2]中交第一公路勘察设计研究院有限公司,陕西西安710068 [3]河南中原高速公路股份有限公司,河南郑州450052

出　　处：《岩土工程学报》2011年第1期159-164,共6页Chinese Journal of Geotechnical Engineering

基　　金：国家自然科学基金项目(51008032);中央高效基本科研业务费专项资金项目(CHD2009JC117)

摘　　要：在土工离心机上安装加载装置和位移、应力量测系统,建立与实际应力相符的离心试验模型,考虑不同工况系统研究了新老路基拼接处治技术及预应力管桩复合地基处治技术对于拓宽路基差异沉降变形的改善控制作用,得出了拓宽工程新老路基差异变形特征和处治技术的处治效果及作用机理。研究结果表明:在拓宽路基拼接带不同层位布设土工材料,虽可消解新老路基的不均匀沉降,但效果不明显,加筋处治使地表以下浅层土体侧向位移减小幅度较大,而深层土体侧向位移改变不大,说明加筋对软基侧向位移的影响范围很有限;采用预应力管桩处理拓宽路基下地基不仅很好地控制拓宽路基的不均匀沉降,还可大大加快施工进度,缩短工期,说明管桩复合地基更适合于工期紧张、沉降控制要求较高的拓宽工程;管桩桩体产生向上刺入变形,由于桩帽和加筋褥垫层的设置,能有效地缓解上刺入深度。Loading devices and displacement and stress measurement systems are installed on the geotechnical centrifuge.A centrifugal model in line with the actual stress is established.Considering different conditions,the treatment techniques for new and old roadbeds as well as the improvement efficiency of prestressed pile composite foundation treatment in differential settlement deformation of road widening are studied.The differential deformation features of the widening project and the effectiveness and mechanism of the treatment techniques are simulated.The results show that for the road widening laid with geotextile materials in different strata,although uneven settlement of new and old roadbeds may reduce,the effeciency is not obvious.With the help of reinforced treatment,the lateral displacement of shallow soil greatly decreases,while that of deep soil changes little,indicating that the reinforcement has limited effect on the lateral displacement of soft soil,Using prestressed pipes to handle road widening can control the uneven settlement,greatly accelerate the construction schedule and shorten the construction period,indicating that the composite piled foundation in soft soil is suitable for road widening projects with urgent construction time and high settlement control requirements.The study also shows that the pipe piles produce upward penetration deformation,and due to pile caps and reinforced cushions,the penetration depth is effectively alleviated.

关 键 词：拓宽路基 差异沉降 处治技术 离心模型 预应力管桩 

分 类 号：TU433[建筑科学—岩土工程]