浅析钻孔灌注桩断桩处理方法

高层建筑、厂房和桥梁基础大都采用钻孔灌注桩。然而，由于设备、地层、人员素质及其他主客观因素的影响，施工中断柱的事故时有发生，必须采取相应的措施加以弥补。     

钻孔灌注桩断桩成因分析与预防

在钻孔灌注桩工程中,断桩事故是危害最为严重而且最难处理的一种事故。造成断桩事故的主要原因,既有可能产生于成孔阶段,也有可能产生于砼灌注阶段,因此必须根据不同阶段采取相应的预防措施。实践表明,必要的预防措施有助于减少断桩事故的发生。     

大口径钻孔灌注桩的施工及断桩处理

在大口径钻孔灌注桩的基础施工中，对第四系覆盖层中砂卵石层、基岩、均采用回转钻钻进，在钻进工艺上，采用泥浆护壁正循环成孔，泵吸后循环清孔，另外还介绍了砼水下灌注断桩事故的处理。     

钦州火电厂钻孔灌注桩断桩控制及模拟研究

以钦州火电厂地基处理为例,通过分析该厂址的工程地质条件与地基处理方式,针对地基处理中出现的钻孔灌注桩的断桩缺陷,提出了相应的防治措施及解决方案。在此基础上,运用FLAC3D数值模拟方法,建立了断桩的差分单元分析模型,求得了不同断桩部位的塑性区、位移、应力变化情况,分析了不同断桩部位对地基加固效果的影响,为工程处理钻孔灌注桩事故提供了一些有益的指导,同时也揭示了断桩机理。     

钻孔灌注断桩事故产生原因及处理措施

简要介绍在钻孔灌注桩施工中发生的断桩事故的原因和处理措施。     

钻孔灌注桩断桩事故的处理与原因分析

结合武汉移动通信枢纽楼工程，介绍了大直径钻孔灌注桩断桩事故的处理过程，分析了出现断桩的原因，给出了解决的对策。     

桩基施工工艺,桩型及桩身缺陷分布

以我国常用的３种桩型（预制桩、沉管灌注桩、钻孔灌注桩）及施工方法为例,研究了其施工工艺引起的桩身主要缺陷及桩身主要缺陷分布规律。     

Application of Hydro-Electric Effect Method to NDI of Piles

This paper presents briefly the essential principle and measurement process of hydro-electric effect method for NDI of piles. In the past three years, more than three hundred piles from twenty project sites inspected with method. Coring piles and comparing dynamic with static tests have proved that hydro-electric effect method is available for engineering with easy operation, quick inspection, and low costs.     

水电效应法桩基无损检测技术的应用

本文简要介绍了水电效应法桩基无损检测的基本原理和测试分析方法。三年多来对20多个工程的300多根桩的检测工作,以及对其中部分桩进行钻孔取芯验证和动测、静测法对比试验表明,该方法是可靠的,能满足工程要求,且具有操作简便、检测快速、费用低等优点。     

超声波透射法在钻孔灌注桩检测中的应用

文章简要介绍了超声波透射法检测钻孔灌注桩质量的基本原理、检测技术和分析方法等，基于对典型实测曲线的分析并结合作者的检测经验，详细描述了应用超声波透射法测桩时的各类桩的缺陷特征。     

Fast 3D Reservoir Simulation and Scale Up Using Streamtubes

This paper presents an implementation of a semianalytical method for oil recovery calculation in heterogeneous reservoirs that is both fast and accurate. The method defines streamline paths based on a conventional single-phase incompressible flow calculation. By calculating the time-of-flight for a particle along a streamline and assigning a volumetric flux to each streamline, the cumulative pore volume of a streamtube containing the streamline can be calculated. Subsequently, the streamtube geometries are kept constant and the effects of the time varying mobility distribution in two-phase flow are accounted for by varying the flow rate in each streamtube, based on fluid resistance changes along the streamtube. Oil recovery calculations are then done based on the 1D analytical Buckley–Leverett solution. This concept makes the method extremely fast and easy to implement, making it ideal to simulate large reservoirs generated by geostatiscal methods. The simulation results of a 3D heterogeneous reservoir are presented and compared with those of other simulators. The results shows that the new simulator is much faster than a traditional finite difference simulator, while having the same accuracy. The method also naturally handles the upscaling of absolute and relative permeability. We make use of these upscaling abilities to generate a coarse curvilinear grid that can be used in conventional simulators with a great advantage over conventional upscaled Cartesian grids. This paper also shows an upscaling example using this technique.     

完整性检测在冲（钻）孔灌注桩的合理应用

通过对3个工程实例的分析,发现在低应变法和声波透射法对冲（钻）孔灌注桩各种缺陷检测中存在不同结果,提出了各种完整性检测的适用范围,使冲（钻）孔灌注桩桩基检测方案和检测工作更加完善、合理。     

A New SPT-Based Method for Estimating Axial Capacity of Driven Piles in Glacial Deposits

Geotechnical and Geological Engineering - This paper proposes a new design method for the axial capacity of driven piles in glacial deposits with the standard penetration test (SPT) based on a...     

Determination of Bearing Capacity for Piles with CASE Method

A method named CASE method is presented for determining the statically axial bearing capacity of piles from dynamic measurements of force and acceleration performed under the impact of a large hammer. The basic equation for calculating resistance against pile penetration is derived. The examples of field measurements are given. In order to use CASE method effectively, it is necessary to determine “damping ”constant by comparison the pile bearing capacity from static method with that from CASE method, or by changing hammer weight or dropping height to cause the Vb to close on zero and to obtain the static bearing capacity of pile.     

凯司(CASE)法确定桩的承载力

本文介绍了用测量大锤撞击作用下的力和加速度以确定桩的静态轴向承载力的凯司(CASE)法。介绍了推导计算桩贯入阻抗力的基本方程,并给出了现场测量的例子。要有效地使用这种方法,就要将其测得的承载力与静力法测得的桩承载力对比来确定“阻尼”常数,或通过改变锤重和落距使V_b。趋近零,获得桩的静承载力,并求得“阻尼”常数。     

沉降柱基灌浆加固处理和倾斜柱子灌浆纠偏扶正实践

介绍了柳钢围炉3号板坯主厂房沉降柱基灌浆加固和因加固引起的柱基抬升、倾斜及倾斜柱子纠偏扶正施工技术，并总结了经验教训。     

低应变法检测PHC桩身缺陷的新认识

通过宁德国际会展中心桩基工程的低应变法检测事例,提出了反射波形上出现与入射波反相反射波并不一定仅是土层反应,断桩也可能导致低应变波形出现明显的反相反射波,进而对该桩基质量进行全面分析、评价,对桩基检测结果作出判断。