粉煤灰取代矿粉在路面基层水泥中的应用研究

利用粉煤灰取代矿粉制备路面基层专用水泥,研究了粉煤灰的掺量对路面基层专用水泥的凝结时间、强度、胀缩特性的影响.结果表明：粉煤灰在掺量为15％的条件下,路面基层专用水泥的凝结时间、微膨胀性能均满足相应的施工要求,强度明显高于P·C32.5级水泥力学性能的指标.且采用粉煤灰取代矿粉生产路面基层专用水泥有效降低了水泥的生产成本,具有良好的经济效益.     

关于全风化花岗岩抗剪强度的探讨

全风化花岗岩是一种具有粘性土和砂性土特性的特殊土,特殊的结构和性质使得土工试验室测定其抗剪强度要求较高.结合目前土工试验室的实际操作情况,对试样剪切过程进行分析,并选择合适的测定方法,可真实地反映全风化花岗岩的抗剪强度.     

拱管桥结构分析

该文结合通州市区域供水东线工程—运石河拱管桥工程设计实例,对拱管桥的内力计算、强度验算及稳定性分析作全面详尽的论述。此外利用M IDAS/CIVIL软件建立该桥计算模型,计算和分析了各工况下拱管桥的受力情况。其分析结果可供工程设计和施工部门参考和借鉴。     

Improved design formulas for the ultimate strength of platings with circular openings and manholes under uniaxial compression

The paper focuses on the ultimate strength of perforated platings with circular openings and manholes, eventually reinforced by ringed or carling stiffeners, in order to develop a comprehensive and rationale format, useful to assess the ultimate capacity of perforated plate panels under uniaxial compression. In this respect, a large number of FE simulations is performed by Ansys Mechanical APDL, in order to provide new design formulas for the ultimate strength of platings with circular openings or manholes and, subsequently, for perforated plate panels reinforced by local stiffeners. The design formulas are developed by properly varying the opening size and the scantlings of ringed or carling stiffeners, in order to provide a comprehensive set of design curves. Hence, the incidence of the opening longitudinal position on the ultimate capacity of perforated platings, without and with local stiffeners, is also investigated. Finally, the proposed equations are applied in a straightforward design example. Based on current results, the new design formulas allow a reliable assessment of the ultimate capacity of platings with circular openings or manholes and the incidence of local stiffeners on the plating ultimate strength, so providing a rationale design format that could be easily embodied in current Rules and guidelines.     

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).     

内河400t散装水泥船设计要点

分析内河散装水泥船的布置和结构特点,在400 t内河散装水泥船设计中,根据相关规范和规定,综合考虑船舶的布置、强度和稳性,根据航道条件合理选择推进方式,保证船舶安全营运。     

沥青稳定基层混合料的矿料级配研究

本研究的目的是选定合理的沥青稳定基层混合料级配,并研究其力学性能和疲劳规律。首先,通过与国外沥青稳定基层常用级配及国内相关级配的比较,以及大量的马歇尔试验和强度试验,初选出沥青稳定碎石1号(公称粒径26.5 mm)和沥青稳定碎石2号(公称粒径31.5 mm)两种级配类型;然后,在M TS810材料试验系统上进行了应力控制的疲劳试验,研究其抗疲劳性能。试验表明,这两种级配的沥青稳定基层碎石混合料的力学性能和疲劳性能优良,能够用于修筑高等级公路的沥青稳定基层。     

水泥稳定碎石无侧限抗压强度与抗压回弹模量的关系

通过室内试验研究水泥稳定碎石基层混合料的无侧限抗压强度和回弹模量,并对其各自影响因素进行分析,对水泥稳定基层的抗压回弹模量与无侧限抗压强度之间的关系作了论述。阐述了建立两者关系的重要意义,并提出两种指标之间的关系式。     

高大加筋土挡墙的安全性分析

结合重庆某滨江路高大加筋土挡墙的现场观测，应用改进的有限元计算方法和强度折减理论对高大加筋土结构的安全性进行评估分析。通过与简化Bishop法进行比较．两者结果比较相近。与其他工程事故资料对比，改进的有限元计算方法计算的滑动面位置更接近实际。有限元强度折减法优点是既能获得墙面变形，又能获得整体稳定安全系数，但安全判断的依据有待进一步分析研究。     

膨胀土公路滑坡变形破坏机理研究

以国道G316线安康~汉阴段K25附近膨胀土公路滑坡为例,分别运用非饱和土强度理论的Fredlund强度公式以及饱和土的有效应力原理,分析了该膨胀土公路滑坡滑带土强度破坏的力学机理,同时运用FLAC2D数值方法模拟了其运动机理与过程,得出了膨胀土公路边坡开挖前后的应力、位移、应变及弹塑性状态变化的规律。