论文部分内容阅读
以广东某钢厂建设项目为背景,通过现场试验测试锤击管桩打入后在距桩不同距离及距地面不同深度处的各地层标贯击数和锤击数等的变化情况,分析预制管桩打入后各地层挤(土)密效应影响范围、程度及变化规律;结果表明锤击管桩进入砂层具有明显挤(土)密效应,粘土层不明显;同一地层,挤(土)密效应影响程度随水平距离增大而减小;同一桩体,砂层挤密效应程度随深度变化呈先增后减趋势;挤密(土)效应具有时间效应,随着应力的重分布,主要影响范围由0~3d可扩大到0~4d;次影响范围为4~8d,8d之外基本不考虑挤(土)密效应。根据上述研究成果,可避免挤(土)密效应在深厚砂层中带来的不利影响、选择合理的桩间距、充分发挥地基承载力潜能,节约投资提高经济效益,对正确认识挤(土)密效应的发生机理及规律,给类似工程具有很好的借鉴意义。
Based on the construction project of a steel mill in Guangdong Province, field tests were carried out to test the changes of standard penetration number and hammering number of various strata at different distances from the pile and at different depths from the ground after the hammering pile was driven in. The results show that the hammering pipe pile has obvious crowding (soil) density effect and the clay layer is not obvious. The same strata, squeeze (soil) ), The effect of close effect decreases with the increase of horizontal distance; the same effect, the degree of crowding effect of sand layer increases first and then decreases with depth; the compaction (soil) effect has time effect, with the stress redistribution , The main influence range can be expanded from 0 ~ 3d to 0 ~ 4d; the secondary impact range is 4 ~ 8d, and the effect of squeezing (soil) is basically not considered beyond 8d. According to the above research results, it is possible to avoid the adverse effect brought by the close effect of squeezing (soil) in the deep sand, to select reasonable pile spacing, to fully develop the potential of foundation bearing capacity, to save investment and to improve economic benefits, The mechanism and rules of the close effect have a good reference for similar projects.