钻孔灌注桩桩头静态破碎参数优化研究  

Study on static crushing parameters optimization of bored cast-in-place pile heads

作　　者：戴选锋 关盛杰 李小龙 王攀 孔德森 DAI Xuanfeng;GUAN Shengjie;LI Xiaolong;WANG Pan;KONG Desen(Qingdao Institute of Geological Exploration, China Metallurgical Geology Bureau, Qingdao, Shandong 266061, China;School of Civil Engineering and Architecture, Shandong University of Science and Technology, Qingdao, Shandong 266590, China;Shandong Key Laboratory of Civil Engineering Disaster Prevent and Mitigation, Shandong University of Science and Technology, Qingdao, Shandong 266590, China)

机构地区：[1]中国冶金地质总局青岛地质勘查院,山东青岛266061 [2]山东科技大学土木工程与建筑学院,山东青岛266590 [3]山东科技大学山东省土木工程防灾减灾重点实验室,山东青岛266590

出　　处：《山东科技大学学报（自然科学版）》2022年第3期75-82,共8页Journal of Shandong University of Science and Technology(Natural Science)

基　　金：山东省自然科学基金项目(ZR2019MEE027);中国冶金地质总局山东局青年科技基金项目(2020-19-9)。

摘　　要：静态破碎技术以其低速加载、过程可控的优势,近年来在混凝土构筑物的拆除中得到广泛应用。为研究静态破碎技术在钻孔灌注桩桩头破除工程中的应用,分析了膨胀孔布孔方式对直径为600 mm桩头静态破碎效果的影响,利用岩石真实破裂过程分析软件(RFPA^(2D))建立了不同布孔方式下桩头破碎的数值计算模型,得到了一些物理试验难以准确测定的数据。研究结果表明:桩头静态破碎是一个持续渐进的过程,膨胀孔周围大致形成三条或两条主裂纹,由于膨胀孔之间的应力叠加效应,裂纹发展方向呈现特定规律:其中一条指向最小抵抗线方向,其余裂纹指向最近膨胀孔处。对于直径为600 mm的桩头破除工程,采取“核心孔+环形均布6孔”的布孔方式,可以达到较好的破碎效果。With its advantages of low loading speed and controllable process,static crushing technology has been widely used in the demolition of concrete structures in recent years.In order to study the application of static crushing technology in the demolition of bored cast-in-place pile heads,this paper first analyzed the influence of expansion hole arrangement on static crushing effect of pile heads with diameter of 600 mm.Then,by using realistic failure process analysis software(RFPA^(2D)),a numerical calculation model of pile head crushing under different hole arrangements was established and some data which were difficult to be accurately measured in physical tests were obtained.The results show that the static crushing of pile heads is a continuous and gradual process and three or two main cracks are roughly formed around the expansion hole.Due to the stress superposition effect between the expansion holes,the direction of crack development presents a specific law:one of the cracks points to the direction of the minimum resistance line and the rest of the cracks point to the nearest expansion hole.For the pile head breaking project with a diameter of 600 mm,the hole distribution method of“core hole plus circular uniform distribution of 6 holes”can achieve better crushing effect.

关 键 词：钻孔灌注桩 静态破碎 桩头破除 RFPA^(2D) 参数优化 

分 类 号：TU470.3[建筑科学—结构工程]