期刊文献+
共找到3篇文章
< 1 >
每页显示 20 50 100
自平衡试桩Q-s曲线理论解析方法研究 被引量:5
1
作者 欧孝夺 白露 +2 位作者 吕政凡 江杰 黄中正 《铁道科学与工程学报》 EI CAS CSCD 北大核心 2022年第2期399-408,共10页
为实现自平衡试桩理论方法更好地应用于基桩承载力测试,提出一种适用于层状地基中单桩承载力自平衡法测试的理论解析转换方法。基于自平衡上、下段桩加载受力模型,假定桩侧荷载传递函数符合理想弹塑性模型,推导出层状地基中上、下段桩... 为实现自平衡试桩理论方法更好地应用于基桩承载力测试,提出一种适用于层状地基中单桩承载力自平衡法测试的理论解析转换方法。基于自平衡上、下段桩加载受力模型,假定桩侧荷载传递函数符合理想弹塑性模型,推导出层状地基中上、下段桩弹性和塑性状态的荷载传递矩阵。再用MATLAB编程得到上、下段桩各微段处轴力、侧摩阻力及竖向变微量,代入精确转换公式中将自平衡试桩结果转换成传统静载测试Q-s曲线,并利用等荷载法求解其极限承载力。结合青岛胶州湾大桥工程试桩实例,采用锚桩法和自平衡法2组试桩工况结果验证该理论解析方法的准确性。研究结果表明:自平衡理论解析计算上、下段桩身各点轴力和侧摩阻力与锚桩法实测数据比较均在误差允许范围内;与传统静压测试、简化转换法相比,该解析转换法Q-s曲线与传统静压试验吻合效果明显优于简化转换法;同时对比2种转换法得到承载力值,简化转换法对于准确测定单桩承载力偏于保守,且不能分析桩身内力特征及承载能力,解析转换方法求解结果精度提高约12.3%。因此,证实了该理论解析方法在实际工程层状地基中有很大的适用性,可在基桩承载力自平衡测试工程中大量推广与应用。 展开更多
关键词 自平衡试桩 荷载传递 层状地基 理论解析方法
下载PDF
Some Results on Position Restriction Scheduling Problems
2
作者 CHEN You-jun LIN Yi-xun 《Chinese Quarterly Journal of Mathematics》 CSCD 北大核心 2008年第2期202-206,共5页
In this paper, we first consider the position restriction scheduling problems on a single machine. The problems have been solved in certain special cases, especially for those obtained by restricting the processing ti... In this paper, we first consider the position restriction scheduling problems on a single machine. The problems have been solved in certain special cases, especially for those obtained by restricting the processing time pj = 1. We introduce the bipartite matching algorithm to provide some polynomial-time algorithms to solve them. Then we further consider a problem on unrelated processors. 展开更多
关键词 position restriction scheduling matching algorithm assignment problem
下载PDF
Study and verification on dispersion coefficient in wave field
3
作者 SHEN LiangDuo ZOU ZhiLi 《Science China(Technological Sciences)》 SCIE EI CAS 2012年第5期1443-1454,共12页
Transport and diffusion caused by coastal waves have different characteristics from those induced by flows. Through solving the vertical diffusion equation by an analytic method, this paper infers a theoretical formul... Transport and diffusion caused by coastal waves have different characteristics from those induced by flows. Through solving the vertical diffusion equation by an analytic method, this paper infers a theoretical formula of dispersion coefficient under the combined action of current and waves. It divides the general dispersion coefficient into six parts, including coefficients due to tidal current, Stokes drift, wave oscillation and interaction among them. It draws a conclusion that the contribution of dispersive effect induced by coastal waves is mainly produced by Stokes drift, while the contributions to time-averaged dispersion coefficient due to wave orbital motion and interaction between current and waves are very small. The results without tidal current are in agreement with the numerical and experimental results, which proves the correctness of the theoretical derivation. This paper introduces the variation characteristics of both the time-averaged and oscillating dispersion coefficients versus relative water depth, and demonstrates the physical implications of the oscillating mixing coefficient due to waves. We also apply the results to the costal vertical circulation and give its characteristics compared to Stokes drift. 展开更多
关键词 dispersion coefficient longitudinal dispersion unsteady flow WAVE
原文传递
上一页 1 下一页 到第
使用帮助 返回顶部