基于高层建筑布局的长沙市整体空间形象塑造

高层建筑的出现标志着城市空间与景观出现一系列新变化,也给人们带来一系列新的城市问题。以长沙市为例,分析了长沙高层建筑对城市整体空间形象的影响,从城市空间形态、总规层面与控规层面不同视角对高层建筑布局结构优化进行探讨。建构长沙"山、水、洲、城"整体空间结构的基本模式为"两圈、两带、一点、五廊",并通过城市整体景观视廊的设立、城市眺望系统的形成、城市两带天际线的塑造等思路来构建长沙"山、水、洲、城"城市整体空间形象,为城市规划管理决策提供参考。     

Description and analysis of building damage due to Pyrgos, Greece earthquake

On March 1993 an earthquake of magnitude M_s = 5·5 shook Pyrgos, a town in Western Peloponnissos, one of the most seismic prone areas in Greece. The damage induced to modern reinforced concrete buildings was rather light in contrast to the damage induced to historic and traditional buildings of adobe, stone or brick masonry which was severe. In order to study the causes of structural damage, detailed data are collected from a rather large statistical sample of 1023 masonry buildings and 22 reinforced concrete framed buildings with visible damage. For each building the number of storeys, the material of construction, as well as the type and the degree of damage are recorded. In addition, consideration is given to the site of the building within the town and the corresponding soil conditions. For reinforced concrete buildings, damage occured mostly in areas with relatively high estimated spectral accelerations and fundamental soil periods of vibration close to those of the buildings. Nevertheless, further analysis is required to explain the selective damage of a very small number of buildings. For masonry houses, the effect of soil conditions is more systematic. Moreover, the effects of the number of storeys as well as the age and material of construction appear to be dominant.     

Simplified estimation of the expected annual loss of reinforced concrete buildings

Performance‐based earthquake engineering procedures have now developed to the point that it is possible to evaluate a range of possible decision variables, including the expected annual monetary loss (EAL). Quantification of the EAL is considered to be particularly useful because it could assist with the identification of effective design and retrofit measures that consider seismic performance over a range of intensity levels. Recognizing, however, that existing procedures for the evaluation of EAL tends to be quite time consuming, this paper builds on a recent proposal to use simplified limit state loss versus intensity relationships to compute EAL via a closed‐form equation, without the need to compile an inventory of damageable components and with freedom in the choice of structural analysis method. Various developments to the simplified approach are made in this paper to allow consideration of loss thresholds, non‐uniform damage distributions and the impact of differences in seismic performance in orthogonal directions. In addition, means of accounting for uncertainties in the simplified EAL assessment are described. The work has focused on the assessment of EAL for reinforced concrete frame buildings with details representative of construction practice adopted in Italy in the 1950s through to the early 1970s. By comparing loss assessment results obtained using a refined methodology with those obtained using the new guidelines developed here for two case study buildings, it is concluded that the simplified approach works well. Future research should therefore aim to further validate the approach and extend it to other building typologies and construction eras. Copyright © 2017 John Wiley & Sons, Ltd.     

城市3维景观模型重建技术研究

3维景观模型越来越广泛地应用于城市建设和管理之中,如何高效快速地构建城市3维景观模型成为一个关键技术问题。地形与地物分层建模法是城市3维景观模型重建领域中的一个热门方法,它采用地形数据叠加建筑物实体来构建3维景观。该方法已成功应用于惠州市3维建模,实践证明该方法建模速度快、操作简单、具有广阔的应用前景。     

A comparison of IBC with 1997 UBC for modal response spectrum analysis in standard-occupancy buildings

This paper presents a comparison of the seismic forces generated from a Modal Response Spectrum Analysis (MRSA) by applying the provisions of two building codes, the 1997 Uniform Building Code (UBC) and the 2000-2009 International Building Code (IBC), to the most common ordinary residential buildings of standard occupancy. Considering IBC as the state of the art benchmark code, the primary concern is the safety of buildings designed using the UBC as compared to those designed using the IBC. A sample of four buildings with different layouts and heights was used for this comparison. Each of these buildings was assumed to be located at four different geographical sample locations arbitrarily selected to represent various earthquake zones on a seismic map of the USA, and was subjected to code-compliant response spectrum analyses for all sample locations and for five different soil types at each location. Response spectrum analysis was performed using the ETABS software package. For all the cases investigated, the UBC was found to be significantly more conservative than the IBC. The UBC design response spectra have higher spectral accelerations, and as a result, the response spectrum analysis provided a much higher base shear and moment in the structural members as compared to the IBC. The conclusion is that ordinary office and residential buildings designed using UBC 1997 are considered to be overdesigned, and therefore they are quite safe even according to the IBC provisions.     

机载LIDAR技术在城市建筑物高度分级中的应用

机载LIDAR技术解决了如何快速、准确地获取地物高度的难题,同时为地物高度信息的应用提供了有效的技术手段。本文根据地理国情普查中建筑物分类指标体系,分析离散点云数据高程关系和分类过程,实现了一种基于点云阶层式分类的城市建筑物高度分级的技术方法,并在Terrascan软件环境下验证了该方法的可行性和快速性。     

高层建筑大范围超深回填地基处理技术

随着我国城市化建设进程的推进,不良土地资源的合理使用是城市发展必然面对的课题.城市在发展扩张中常常碰到砂石坑或地基条件很差的地段,其地基处理的方法、地基处理的效果影响工程造价,影响上部结构的质量安全.某工程地基为大范围深度达17 m的砂石坑,采用了大面积砂石坑的地基处理技术,地基达到了设计承载力要求,取得了良好的经济、技术效益.     

Seismic loss estimation of non‐ductile reinforced concrete buildings

Non‐ductile reinforced concrete buildings represent a prevalent construction type found in many parts of the world. Due to the seismic vulnerability of such buildings, in areas of high seismic activity non‐ductile reinforced concrete buildings pose a significant threat to the safety of the occupants and damage to such structures can result in large financial losses. This paper introduces advanced analytical models that can be used to simulate the nonlinear dynamic response of these structural systems, including collapse. The state‐of‐the‐art loss simulation procedure developed for new buildings is extended to estimate the expected losses of existing non‐ductile concrete buildings considering their vulnerability to collapse. Three criteria for collapse, namely first component failure, side‐sway collapse, and gravity‐load collapse, are considered in determining the probability of collapse and the assessment of financial losses. A detailed example is presented using a seven‐story non‐ductile reinforced concrete frame building located in the Los Angeles, California. Copyright © 2012 John Wiley & Sons, Ltd.     

地籍测量在城镇土地管理中的应用

地籍测量是土地管理工作的重要基础。它是以地籍调查为依据,以测量技术为手段,从控制到碎部,精确测出各类土地及其附着物的界线、位置、面积、质量、权属和利用现状等基本情况及其几何形状的测绘工作。     

城市典型建筑地震损失预测方法II：地震损失估计

本文在文[1]的基础上，给出城市典型建筑地震损失估计方法。首先，给出砖砌体结构、排架结构和钢筋混凝土结构的破坏分级描述；其次，介绍城市地震人员伤亡及经济损失估计方法。结合文[1]的结构易损性分析方法，以宁波市为例，给出了市区典型建筑的震害矩阵，并对地震作用下的人员伤亡和财产损失进行了估计。