振冲碎石桩在粉砂地基中的应用     

王剑峰 《林业科技情报》2012,(3):104-105

以设计为依据,结合工程实际情况,通过碎石桩在粉砂地基中的试桩实验,提出如何控制碎石桩施工时的水压、电流、留振时间等施工要点,以便更好的提高碎石桩的使用效果。  相似文献   

灌注桩施工质量通病的防治     

王忠和  李沿革 《林业科技情报》2003,35(2):26-27

混凝土和钢筋混凝土灌注桩工程施工时,经常发生一些质量通病,本文结合这些质量通病,提出预防措施和处理方法。  相似文献   

多年冻土地区钻孔灌注桩回冻初期承载力的计算     

刘秀  贾艳敏 《森林工程》2007,23(3):45-47

多年冻土地区钻孔灌注桩在施工过程中产生的各种热量引起了桩周冻土一定范围升温及融化，本文按照桩周冻土颗粒的不同，编制Visual Basic6．0程序计算桩周融土压力，从而计算回冻初期单桩承载力。所得结果与按照铁路桥涵与公路桥涵规范公式计算结果对比。并结合工程实例对多年冻土地区的钻孔灌注桩回冻初期的单桩承载力进行了计算分析。所得结论可为多年冻土地区桥梁工程施工计划的制定提供参考。  相似文献   

JK270+688大桥挖孔桩施工技术     

何佼龙  闫昌明  辛自洋 《森林工程》2003,19(1):48-49

结合所在地的实际情况 ,经施工方案比较 ,采用挖孔桩方案。并着重介绍了施工工艺 ,困难地段处理及混凝土的灌筑。施工中全方位控制施工的各个环节 ,实践证明 ,该方法是一种可操作性强、并对质量控制措施有效、可行的方法。  相似文献   

水泥搅拌桩的设计、施工及检测   总被引：2，自引：0，他引：2  

汤建南  郭正崔 《林业科技情报》2002,34(4):9-11

对水泥搅拌桩在设计、施工、检测等方面作了全面阐述,并且提出了若干注意事项及合理化建议。  相似文献   

Analysis of the Strength and Stability of Type CYM Hydraulic Anchor Station     

Lai Yunin  Gao Tianin 《保鲜与加工》1994,(3):135-140

The structure of type CYM hydraulic anchor station and its principle ofoperation are briefly introduccd,and its strength and stability are analyzed.  相似文献   

Increase of Wave Velocity in Precast Pile along with Time and Its Analysis     

ZHANG Ming - yi  ZHANG Wei 《保鲜与加工》2006,(6):62-64105

Low strain dynamic testing on actual pile was conducted to investigate if the wave velocity is varied in the installed pre-cast pile.It was found that the wave velocity of the pile is raised along with time.The analysis has been carried out through with one dimension and three dimension stress wave propagation theories.Among various factors influencing the rise of wave velocity,the factor of the side soil contribution is the chief one.The soil around the pile works jointly with the pile,as if to enlarge the section size of the pile.Both the increase of wave velocity and the bearing capacity of pile are consistent.So the time effect of wave velocity can be used to study the time effect of bearing capacity of the pile and to determine the bearing capacity of piles.  相似文献   

Dynamic Behavior of Geogrid Reinforced Pile Supported Embankments under Moving Load     

LIU Feiyu  YU Wei  YANG Fengyun  ZHANG Mengxi 《保鲜与加工》2012,(3):16-20

In order to investigate the dynamic behavior of geogrid reinforced pile supported embankments (GRPS) under moving load, a three dimensional coupled mechanical and hydraulic model was built by FLAC 3D. The results from two cases including unreinforced and no pile embankments, and geogrid reinforced pile supported embankments were presented. The behaviors of vertical displacement, pile soil stress ratio, excess pore water pressure, and vertical acceleration under two cases were compared and discussed. Additionally, studies on the effect of speed and weight of the moving load were performed. It is indicated that the value of vertical displacement, pile soil stress ratio, excess pore water pressure, and vertical acceleration of GRPS decrease evidently compared with those of unreinforced and no pile embankment, which is caused by the soil arching effect and the reinforcement effect. It is also shown that the greater the axle load value is, the less the beneficial effect of GRPS on the vertical displacement. With the increase of the moving speed of the load, the vertical displacement increases.  相似文献   

Numerical Analysis on Bearing Capacity of Piles Subjected to Side Loads     

YAO Wenjuan  CHEN Shangping  CHEN Jie  CHENG Zekun 《保鲜与加工》2012,(4):6-11

Besides the loading applied by the upper building, the piles are often subjected to indirect loading such as side loads. These kinds of loads would cause the pile bear additional force (negative skin friction), which may be large enough to reduce the bearing capacity and cause structural failure of a pile. By establishing the numerical model of pile soil interaction, the bearing capability of pile under side load was analyzed. The joint effect of different magnitude and the distance of the side load on the skin friction were focused. The joint effect of length of the pile and the distance of side load on the skin friction was discussed. The expression of the two combination relationship was obtained. Meanwhile, by using the least square method, the expression of total skin friction on different side load combination was achieved. And based on the statistical analysis of the dispersion coefficient, the function expression was proved to be of high precision. The results show that when k, which indicates the relative relation of side load distance s and the side load magnitude Q, increases to 32, the value of negative skin friction goes to zero. When c, indicating the relative relation between pile length L and side load distance s, increases to 0.5, the value of negative skin friction goes to zero. Beyond limit value of these two relative relationships, the bearing capability of the pile will not be affected by side loads.  相似文献   

Analysis of Concrete Damage Model in Pile Body Stress Test     

WU Zhiwei  QI Jianguo  JIANG Yong  GUO Puning  WEI Jincai 《保鲜与加工》2012,(Z1):174-178

Automatic pile body stress test system is used in an in-situ static loading test. It’s found that strain process line has a step-like feature. When unloading, as the rebound amount of soil is less than the amount of pile body, negative frictional resistance exists in the soil. It’s considered that concrete damage model can explain the modulus “reduced” phenomenon of calibration section’s concrete. Based on damage mechanics theory, a function of modulus of concrete and its own strain are obtained. According to actual strain of pile body, different modulus are adopted to calculate pile body stress. The in-situ test results show that this method is more reasonable.  相似文献