复杂坡面地基中钻孔灌注桩的应用研究  

Application of Borehole Cast Pile in Complex Sloping Foundation

作　　者：李婕[1] 张学民[2] 顿志林[1] 

机构地区：[1]河南理工大学土木建筑学院,河南焦作454000 [2]中南大学土木建筑学院,湖南长沙410075

出　　处：《采矿与安全工程学报》2006年第3期337-340,共4页Journal of Mining & Safety Engineering

摘　　要：为了解决钻孔灌注桩在水下复杂坡面地基中穿过回填碎石层和淤泥层时易产生缩颈、断桩等缺陷问题,探讨了钻孔灌注桩施工辅以桩底后压浆技术和桩侧前注浆技术大幅度提高基桩承载力及桩身完整性的作用机理,提出了成孔过程中遇到大体积回填岩块时采用微差弱爆和在碎石层与淤泥层中沉放钢套管的技术措施,采用声波透视法对桩身完整性进行了检测和评价.结果表明,应用桩前注浆技术对桩周岩土体进行预加固,浆体固结后形成防渗帷幕,有效改善了桩侧岩土体的整体物理力学特性,解决了成孔坍塌、桩体偏位等问题.经超声波完整性检测以及桩身混凝土钻芯试样的测试表明试桩无断桩和缩颈等缺陷,经综合评定试桩为I类桩.In borehole pile casting underwater and on a complex sloping foundation passing through the backfilled gravel and silt layer, the section reduction and pile breaking may easily take place. Aiming at this problem, the mechanism of borehole pile casting assisted by mudjacking from behind the pile base and grouting from the side of piles is discussed, which can greatly improve the bearing capacity and the integrity of the piles. Techniques of millisecond blast and steel bushing were proposed to solve the problem encountered in the process on backfilling of large volume rock blocks. The integrity of pile body was checked and evaluated by the acoustic wave perspective method. The results show that the gravel and soil layer around the piles are reinforced preliminarily to form a watertight wall, which has effectively improved the physical and mechanical properties and then solved such problems as the borehole collapse and incline of piles. Ultrasonic detecting result indicates that no defect such as pile breaking or section reduction is found.

关 键 词：地基处理 坡面岩石地基 钻孔灌注桩 注桨技术 无损检测 

分 类 号：TD473.14[矿业工程—矿山机电]