交通荷载影响下土石混填高路堤沉降规律数值分析

土石混填高路堤作为山区高速公路建设常采用的一种路基形式，其工后沉降控制已成为山区高速公路建设的难题。建立了交通荷载作用下高路堤动力模型，利用有限元软件ANSYS进行了数值仿真分析，研究了车速为100km/h三车道三辆车交通荷载作用下高路堤的沉降规律，分析了土石混填高路堤在其影响下的沉降与循环次数关系，为施工控制沉降措施提供了依据。     

Analysis of the accident of the MVNakhodka. Part 1. Estimation of wave loads

MVNakhodka collapsed and broke in two on January 2, 1997 in the Sea of Japan, giving rise to a serious and disastrous oil spill on the coastline of Japan. During the inquiry into the cause of the accident, one of the main tasks of the inquiry committee was to identify the external loads which made the ship structure collapse. Among the several possible scenarios for the accident, after careful examination, the wave loads in the heavy weather at the time of the accident were taken to be the most plausible cause. The results of that research are described in two papers, and the present paper deals with the way in which wave loads on theNakhodka at the moment of the accident were estimated. We first describe the details of the accident such as the location, the sea condition, the loading condition, and the ship's heading speed. Then the static loads resulting from the distribution of the cargo weight and the buoyancy are given to show that the static bending moment at the time of the accident caused extreme sagging. Next the wave loads in the irregular waves, calculated by the nonlinear time domain simulation program SRSLAM, are presented. It is shown that the bending moment in the waves reaches 1 087 800 KN^*m at maximum SS 6.9, which is where the hull girder collapse took place. It was concluded that the ship broke in two because the bending moment exceeded the hull girder strength which had been reduced due to corrosion, taking into account conclusions derived from the research dealing with the structural strength aspect. We also discuss the stochastic significance of the estimated value and nonlinear nature of the peak distribution, in addition to the effects of the ship speed and wave heading on the wave load estimation. This article is based on an article that appeared in Japanese in the Journal of the Society of Naval Architects of Japan, vol. 183 (1998).     

超小水线面单体船波浪载荷确定方法探讨

通过分析波浪和船体的相对位置,利用微段载荷求和的方法计算静波浪载荷,提出超小水线面单体船的波浪载荷计算方法,实例计算表明在静水平衡状态的基础上,可以有效地计算其静波浪载荷,为超小水线面单体船的研究提供参考。     

自平衡试桩法荷载箱位置设计探讨

对自平衡试桩法的荷载箱位置设计问题及相关的辅助措施进行探讨。     

高速公路潜埋偏压隧道力学计算分析

为了计算和分析浅埋隧ig-衬结构内力，建立了隧道支护和开挖过程数值计算模型，并提出了一种位移反演围岩参数识别的方法，得到了界牌坳隧道破碎带围岩的4个基本综合参数（E、μ、c、Ф）。最后，将反演计算所得破碎带围岩参数输入界牌坳隧道二衬内力数值计算模型，计算各施工步隧道右洞二衬的内力变化情况，并对计算结果进行了分析，得到了几个结论，对现场施工具有一定的指导作用。     

贝克曼梁测试路基表面弯沉修正研究

用贝克曼梁法测试路基表面弯沉在公路工程中得到广泛应用,测试中由于受车型多样化、贝克曼梁弯沉仪支点和百分表支架位置以及计算理论与实际不符等影响,测得的弯沉值需要进行修正。针对以上3个方面,本文分析了非标准轴载的弯沉换算、弯沉仪支点变形和百分表支架变形对弯沉测试结果的影响、支点和支架变形对弯沉测试结果的影响。根据弹性半空间理论,建立了不同轴载作用下的弯沉换算公式;通过理论分析和验证计算,提出了实测弯沉值的修正系数。     

摆臂式平衡悬架的受力分析

分了摆臂式平衡悬架机构的轴荷及制动时左右轮制动力距的不平衡问题，介绍了选择摆臂式平衡悬架机构应注意的问题。     

长期循环荷载作用下管桩侧阻力试验研究

对软土地区静压管桩的静、动载试验结果进行分析,发现在工作荷载作用下软粘土中桩侧摩阻力呈抛物线分布,在循环动荷载下存在退化效应,并对此进行初步分析。分析结果表明:在动力循环荷载作用下,桩身上部软土层出现弱化现象,导致桩身上部的侧摩阻力减小,桩的下部粉质粘土与粉砂层侧摩阻力有所增加,但这种现象随动载循环次数的增加趋于稳定。     

基于倒拆法对重庆朝天门长江大桥进行力学分析

重庆朝天门长江大桥为世界第1跨公轨两用拱桥,设计中主要以应力控制为主。采用倒拆法对该桥的结构杆件力学特性进行研究分析,重点介绍该桥施工中的合理压重和合理扣索力的计算,并提出相关建议。     

部分斜拉连续刚构桥静载试验及有限元分析

以一座三跨连续刚构部分斜拉桥荷载试验为例,按照等效弯矩进行加载,通过各荷载工况下各控制部位测点应力、位移测试结果与有限元计算值相比较,分析该桥的强度和刚度特性。