温州世贸中心大厦超深大直径钻孔灌注桩施工技术

介绍了超深大直径钻孔灌注桩在温州世贸中心大厦桩基工程中的应用情况，对其施工中出现的主要问题进行了分析和处理，并提出了解决措施。     

Multifield coupling model and its applications for pile foundation in permafrost

In the construction of Qinghai-Tibet railway,to avoid diseases caused by frost heave and thaw col-lapse of frozen ground,besides the normal bridges over the rivers,a lot of dry bridge structures have been built to replace subgrade in the regions of high tem-perature and high ice content frozen soil.So,the problems on forming mechanism of bearing capacity of pile foundation in cold regions already become one of hot spot problems in frozen soil engineering.Freezing force and frost heave force ar…     

Pseudo‐dynamic seismic response of reinforced concrete frames infilled with non‐structural brick masonry

This paper presents pseudo‐dynamic test results on the in‐plane seismic behaviour of infilled frames. Thirteen single‐storey, single‐bay, half‐size‐scale, reinforced concrete‐frame specimens, most of which infilled with non‐structural masonry made of perforated bricks and cement mortar are tested. The infills are in contact with frames, without any connector; openings are not covered. The frames are different in their strength and details, reinforcement grade, and aspect ratio. Seismic input is the 1976 Tolmezzo (Friuli, Italy) ground acceleration, to which specimens are subjected two times: virgin and damaged by the previous test. The global seismic response of initially virgin infilled specimens considerably differs from that of bare specimens. This follows a dramatic change of properties: compared to a bare frame, the initial stiffness increases by one order of magnitude, and the peak strength more than doubles. The peak drift lessens; however, the displacement ductility demand does not. The energy demand is greater. Nevertheless, the influence of infill decreases as damage proceeds. Displacement time histories of damaged specimens are quite similar. At the local level, infill causes asymmetry and concentration of the frame deformation. Copyright © 2005 John Wiley & Sons, Ltd.     

桩底注浆钻孔灌注桩承载力的研究

通过天津地区几例钻孔灌注桩桩底注浆的静载荷试桩结果 ,分析天津地区钻孔灌注桩桩底注浆单桩竖向极限承载力标准值的估算方法     

海上钻孔灌注桩成孔施工技术

介绍了东海大桥钻孔灌注桩基础的施工技术 ,对一些关键技术做了详细说明 ,还讨论了海上钻孔灌注桩施工成孔设备的选择及所用的淡水泥浆的配制     

植物加固路堤边坡浅层土体分析及工程应用

在总结植物加固黄土路堤边坡浅层土体的机理之后,结合宝中铁路实际工程,对紫穗槐和柠条两种植物的加固效果进行了详细的分析。     

挤扩支盘桩极限承载力的预测

用双曲线方法对110根挤扩支盘桩的极限承载力进行预测,并与直杆桩预测结果进行对比。结果表明由于支盘桩受力性状复杂,加载前期和中期预测精度较高,后期较低,误差超过15%;支盘桩的沉降曲线出现台阶时预测值与实测值误差较大;支盘桩极限承载力的预测精度与工程地质条件和桩本身的参数密切相关,桩身参数和地质条件相同条件下各桩预测精度比较接近。总体上直杆桩的预测结果优于支盘桩。     

云南省祥(云)-临(沧)公路红土坡隧道变形原因及加固方案

云南省祥(云)-临(沧)公路红土坡隧道，在施工过程中变形严重，洞内数次冒顶、产生地面陷落，并诱发滑坡，严重影响了施工进度并造成较大经济损失。文章根据现场勘查及变形监控量测资料，详细论述了隧道变形特点，从地层岩性、构造、地应力条件、地下水作用、施工工艺、滑坡影响等方面综合分析了隧道变形原因。红土坡隧道变形是软弱的地层岩性、地应力条件改变、地下水作用、施工工艺以及滑坡偏压等各种因素共同作用的结果。且隧道变形诱发滑坡，滑坡又促使隧道进一步变形。基于此，文章提出了首先对滑坡进行支挡，再对隧道围岩进行加固的整治思路，并提出具体工程方案。整治工程实施后，红土坡隧道变形已得到完全控制，取得良好的治理效果。     

Modelling load–displacement response of driven piles in cohesionless soils under tensile loading

A new methodology for deriving the uplift load–displacement response of long driven piles in cohesionless soils is proposed. This method accounts for the effects of the friction fatigue processes during pile driving and the existence of locked-in residual stresses at the end of pile driving before commencing the pile load test. A hyperbolic formulation is utilized to simulate the nonlinear load transfer curves (the so-called t–z curves). The utility of this technique is demonstrated for a field pullout load test on a driven pile in sand. Predicted and measured load–displacement curves showed good agreement, indicating that this approach yields reasonable results as long as representative input parameters are employed.     

桩基筒形翼状钻头的改进设计及应用

针对浙江省温州市世贸中心大厦桩基施工中硬岩钻进时出现的堵管、卡钻和效率低等问题,从所钻地层和钻头的磨损分析出发,提出了钻头的改进设计方案.改进型筒形翼状钻头比原先使用的平底滚刀钻头增加了18个孕镶金刚石-针状硬质合金复合式钻齿和3个钎头,并按受力特点进行了合理分布.实际钻进效果表明改进型钻头应用于超深、大直径钻孔的钻进效率较高、钻进过程平稳.针对钻头的实际磨损情况提出了钻头进一步改进设计的建议.