Influence of the soil–structure interaction on the fundamental period of buildings

This paper includes an investigation of the influence of the soil–structure interaction (SSI) on the fundamental period of buildings. The behaviour of both the soil and the structure is assumed to be elastic. The soil‐foundation system is modelled using translational and rotational discrete springs. Analysis is first conducted for one‐storey buildings. It shows that the influence of the SSI on the fundamental frequency of building depends on the soil–structure relative rigidity K_ss. Analysis is then extended for multi‐storey buildings. It allows the generalization of the soil–structure relative rigidity K_s to such complex structures. Charts are proposed for taking into account the influence of the SSI in the calculation of the fundamental frequency of a wide range of buildings. Copyright © 2007 John Wiley & Sons, Ltd.     

Life-cycle cost analysis of design practices for RC framed structures

The objective of this study is to perform life-cycle cost analysis on three design practices namely weak ground storey, short and floating columns and their combinations. Life-cycle cost analysis is recognized as the only suitable tool for assessing the structural performance when the structure is expected to be functional for a long period of time. Life-cycle cost analysis is considered in this study assessing the behaviour of the three design practices against earthquake hazard. Although, a number of checks are performed in order to reduce the influence of these design practices on the seismic behaviour of reinforced concrete (RC) framed structures, it was found that the total life-cycle cost of partially infilled RC designs is significantly increased compared to that of the fully infilled one. Through the test example examined in the framework of this study general conclusions are obtained regarding the behaviour of the three design practices.     

湛江一次降水过程的最佳雨滴谱分析

简述采用滤纸色斑法对一次层积云降水过程进行取样 ,取得 2 9份雨滴谱 ,通过 4种不同方法 ,对这次雨滴谱进行拟合 ,并将所得经验公式进行优化 ,取得本次降水的最佳雨滴谱分布方程     

德州市农业气象预报系统的设计

“德州市农业气象预报系统”是用VB 5．0和FoxPro 5.0和FoxPro 2.6两种语言开发的软件，并采用面向对象设计技术。通过简述该软件设计过程，阐明设计该软件的思路和方法。     

农业生态系统模式的优化设计探讨

对农业生态系统模式的优化设计原则、内容、方法与步骤进行了探讨。认为模式优化设计包括5大原则，即区域适宜性原则、实用性原则、经济与市场原则、持续性原则和科学性原则；农业生态系统模式设计的主要内容包括总体目标设计、产业结构设计、时空结构设计、食物链网设计、环境与生态形象设计、物质与资金投放和输入输出设计、技术体系设计、面向对象设计及系统集成与优化；农业生态系统设计的基本程序包括系统环境辨识、系统诊断、系统模型分析和方案设计、系统评价和方案选优、系统运行及反馈修正等内容。     

GPS工程控制网的若干特殊问题

根据ＧＰＳ定位技术的优点，讨论了建立ＧＰＳ工程控制网在踏勘、设计、观测及数据处理方面的若干特殊问题，并提出高精度工程控制网ＧＰＳ数据处理方案。     

基于关系数据库的地形图符号库的设计

根据地形图符号的特点，给出了地形图符号的分类和定义，并根据地形图符号的构造函数设计了基于关系数据库的地形图符号库。点线面符号均采用关系数据库的记录描述，从而使得符号的配置独立于具体的符号和图形，同一程序基本上可完成所有符号的绘制，方便了符号库的维护和更新，本符号库以ＡｕｔｏＣＡＤ Ｆｏｒ Ｗｉｎｄｏｗｓ作为图形环境，用Ｂｏｒｌａｎｄ Ｃ＋＋作为开发工具开发。     

大地网三类设计的应变分析法

本文针对大地网三类设计的质量标准问题,提出了一种新方法:应变分析法。它可以根据区域性的尺度、旋转、变形三个应变参数的变化,来发现网的局部区域性系统差或粗差;并能较明晰地反映出新增观测值对原网的局部改进或细节改进。     

3-D shell analysis of cylindrical underground structures under seismic shear (S) wave action

The 3-D shell theory is employed in order to provide a new perspective to earthquake-induced strains in long cylindrical underground structures, when soil-structure interaction can be ignored. In this way, it is possible to derive analytical expressions for the distribution along the cross-section of axial, hoop and shear strains and also proceed to their consistent superposition in order to obtain the corresponding principal and von Mises strains. The resulting analytical solutions are verified against the results of 3-D dynamic FEM analyses. Seismic design strains are consequently established after optimization of the analytical solutions against the random angles which define the direction of wave propagation relative to the longitudinal structure axis, the direction of particle motion and the location on the structure cross-section. The basic approach is demonstrated herein for harmonic shear (S) waves with plane front, propagating in a homogeneous half-space or in a two layer profile, where soft soil overlays the bedrock.     

地下水浮力对建筑工程设计施工的影响

地下水的浮力对结构设计和施工有不容忽视的影响。结构抗浮验算与地下水的性状、水压力和浮力、地下水位变化及意外补水有关。提出设计水位计算浮力的概念，以及抗浮设计的方案及措施。