Field study of plastic tube cast-in-place concrete pile

The compositions, technical principles and construction equipments of a new piling method used for ground improvement plastic tube cast-in-place concrete pile were introduced. The results from static load tests on single piles with different forms of pile shoes and on their composite foundations were analyzed. The distribution patterns of axial force, shaft friction and toe resistance were studied based on the measurements taken from buried strain gauges. From the point of engineering application, the pile has merits in convenient quality control, high bearing capacity and reliable quality, showing higher reasonability, advancement and suitability than other ground improvement methods. The pile can be adopted properly to take place of ordinary ground improvement method, achieving greater economical and social benefits.

振动沉管施工素砼桩挤土效应研究

素砼桩复合地基是高速公路软土地基处理的常用方法;当其采用振动沉管法施工时,会有明显的挤土效应。通过广东省某高速试验段原位试验,对较小桩间距下不同施工方案桩体及土体在不同深度的水平位移量进行了测试和分析。结果表明:在素砼桩桩间距为1.2 m时,连续振动沉管施工成桩质量较差,不宜采用;而采用隔桩跳打施工时,桩体沿纵深方向不同深度水平位移量较小,桩体倾斜度满足设计要求;另外补桩施工时,周围桩体不同深度水平位移量明显小于土体位移量,桩身位移变化小,成桩质量良好。

组合桩型复合地基在软土地基加固中的应用

文中结合具体工程实例,介绍了素砼沉管灌注桩(CFG桩)结合碎石桩形成组合桩型复合地基加固软土地基的处理方法,通过对组合桩型复合地基的施工及静载荷试验,验证了承载力计算方法的可行性。也表明采用此方案加固淤泥质、泥炭质土地基是因地制宜,技术可行,较为经济的地基处理方案。

素混凝土微型沉管灌注桩复合地基的应用

素混凝土微型沉管灌注桩属于新型的软土地基处理技术。文章通过工程实例,详细地阐述了其设计的理论原理,实际的测试技术依据,原理及方法,证明了此地基处理技术的经济可行性和富有成效性。

茶亭街地下交通配套工程围护结构新技术应用综述

本文介绍了福州茶亭街地下交通配套工程围护结构采用长套筒旋挖钻孔灌注桩、三重管水泥旋喷桩等多项新技术的应用,解决了砂层中孔壁坍塌、遇大面积地下管桩障碍物,临近建筑物"侵界"等技术难题,可供同类工程参考借鉴。