Structural performance and economics of tall high strength RC buildings in seismic regions

For a multitude of economic and societal considerations, high rise structures are on the increase. This in turn promotes the use of high strength materials to reduce column size and construction times. Whereas design guidance and engineering understanding of high strength RC structures under static loading is well‐developed, little work has been undertaken on the economics of whole buildings and their performance under earthquake loading. In this paper, 10 buildings of 24 stories are designed and detailed according to modern seismic codes. The buildings are all nominally equivalent, using a stiffness equivalence criterion and its derivatives. The cost of construction is compared in terms of steel, concrete and formwork. The static inelastic response of the buildings is also assessed, followed by a full nonlinear dynamic analysis of all buildings using three earthquake records at the design acceleration and twice the design value. Comprehensive assessment of the static and dynamic results is undertaken. It is concluded that the cost increase is mainly due to the steel, whilst significant member reductions may be availed of by using high strength concrete. The behaviour of high strength concrete structures is not inferior to that of normal strength materials. Indeed, it is observed that lower levels of overstrength can be achieved in high strength materials than in their normal strength counterparts, mainly due to the over‐reinforcement of the latter to resist vertical forces. Recommendations on the use of equivalent cracked stiffness for period calculation in design, and also effective periods for use in displacement‐based design, are given. Copyright © 1999 John Wiley & Sons, Ltd.     

Experimental investigation of dry mechanical beam–column joints for precast concrete based frames

This paper proposes dry mechanical beam–column joints for fully restrained moment connections of concrete components. This novel joint can be used for reinforced concrete precast frames and steel–concrete composite precast frames. The new dry mechanical joint consists of extended steel plates with bolts designed to transfer tension and compression forces, providing fully restrained moment connections at the beam–column joint. The extended end plate with bolts introduced for column‐beam joint assembly was originally used in the steel moment frame, as introduced in AISC 358. This study developed similar but unique mechanical joint details for concrete frames in order to provide fully restrained moment connections for both steel–concrete composite precast frames and reinforced concrete precast frames. Experimental and analytical investigations were performed to verify the structural behavior of fully restrained moment connections for concrete components in order to identify the parameters that influence the structural behavior of dry mechanical moment concrete connections. These connections are expected to be used in modular offsite construction for buildings and heavy industrial plants. Copyright © 2016 John Wiley & Sons, Ltd.     

以磷石膏为模板的节能与结构一体化研究

介绍了以磷石膏为节能材料的节能与结构一体化钢筋混凝土网格式框架结构的施工特点,并与常规框架结构作了比较,同时就现浇磷石膏轻质填芯的钢筋混凝土网格大板楼盖相关计算及施工方法作了论述,以期证实此类结构的优越性。     

高层民用建筑劲钢混凝土施工技术初探

结合具体工程实例,提出了高层民用建筑劲钢混凝土的施工工艺流程,详细地介绍了型钢构件的施工过程,并且阐述了施工中的关键控制措施,以积累劲钢混凝土施工经验,可供同行参考借鉴。     

Seismic collapse analysis of high‐rise reinforced concrete frames under long‐period ground motions

Structural damages associated with buckling of longitudinal reinforcing steel and crushing of concrete induce strength and stiffness degradation in reinforced concrete (RC) beams and columns. This paper presents a numerical investigation on earthquake‐induced damages and collapse of typical high‐rise RC buildings model incorporating strength degradation (SD) effects. In a simple finite‐element analysis program with the generalized stress fiber discretization, hysteretic constitutive models primarily dominate the inelastic behavior. Buckling of reinforcing steel and crushing of confined concrete are taken into accounted to the stress–strain relationship of fiber elements. The SD effect in components with small hoop ratio tends to amplify the seismic responses high‐rise RC moment‐resisting frames when the intensity of ground motions exceeds the design level. Buckling of steel rebar and crushing of concrete should be fully considered together with the P‐Δ effect for collapse simulations.     

钢管混凝土柱在多层建筑中的应用

本文介绍了钢管混凝土柱在多层建筑中的应用,以两个试点工程为例,对钢管混凝土柱在多层房屋中的应用、框架节点构造、抗侧力桁架和综合经济效益予以分析,以供设计人员参考。     

门式刚架轻型钢结构在大空间建筑中的应用研究

介绍了大空间结构可采用的另一种更经济合理的结构形式———门式刚架轻型钢结构 ,阐述了该结构形式的计算理论、设计方法和构造措施 ,并通过对涿州影视基地 2号摄影棚设计中的门式刚架轻型钢结构和网架 +混凝土围护结构两方案的比较分析表明 ,在大空间结构中 ,轻钢结构比钢筋混凝土结构更经济实用。     

谈某高层建筑施工质量控制要点

从项目部管理、"三线"控制、混凝土标号、施工工序质量控制等方面入手,系统分析了高层建筑施工质量控制要点,以保证高层建筑的施工质量,从而建造出优质的建筑工程。     

钢管混凝土柱-剪力墙组合框架抗震性能分析

通过在钢筋混凝土剪力墙边缘设置边框,利用边框对墙板的约束效应,可明显提高剪力墙的延性,改善其抗震性能.边框的形式主要有钢筋混凝土边框、型钢混凝土边框、钢管混凝土边框等,其中,钢管混凝土组合剪力墙具有经济性好、施工方便等优点.应用ANSYS有限元程序对钢管混凝土组合剪力墙的滞回性能进行计算和分析,结果表明这种结构体系具有良好的延性和耗能能力.     

谈中高层异形柱框剪结构剪力墙的竖向设置

通过对中高层异形柱框剪体系的几种结构设计方案进行计算、分析和对比，讨论了剪力墙沿房屋高度的设置问题，提出了剪力墙沿竖向在建筑物顶部的1／3处采用金字塔型布置方案，该方案既降低了工程造价又有利于顶部空间灵活布置，同时也避免了剪力墙沿竖向某层截断造成的结构竖向刚度突变，可以将该结构方案作为中高层异形柱框剪结构体系的推荐优选方案。     

Assessment of the seismic performance of old riveted steel frame–RC wall buildings

Seismic performance assessment of old dual riveted steel frame–RC wall buildings using the nonlinear dynamic procedure is presented. The study is based on an existing nine-storey building located in Wellington, New Zealand. The building is representative of medium rise steel framed buildings from the first half of the 20th century.A three dimensional numerical model of the building was developed in an inelastic structural analysis program. Nonlinear characterisations necessary for the prediction of the inelastic cyclic behaviours of the structural components were incorporated into the numerical model. Details of the structural configuration and member properties for the analyses were determined from the original engineering drawings, the construction specifications, as-built concrete strength test results and literature on properties of steel sections used around the period the building was constructed. The inelastic time history analyses were conducted using a suite of seven earthquake records relevant to the seismicity of the building's location.Modal properties of the numerical model compare well with results of a physical test conducted on the building. The implemented modelling procedure appeared to have predicted the most probable seismic performance of this type of building, which would not have been captured by other simplified procedures. The assessment also highlighted the adverse effects the characteristics and location of the walls have on the seismic performance of this type of building by introducing significant torsional and vertical irregularities.     

Analytical investigation of the seismic performance of RC frames rehabilitated using different rehabilitation techniques

The objective of this study is to investigate analytically the effectiveness of different rehabilitation patterns in upgrading the seismic performance of existing non-ductile reinforced concrete (RC) frame structures. The study investigates the performance of two RC frames (with different heights representing low- and high-rise buildings) with or without masonry infill when rehabilitated and subjected to three types of ground motion records. The ground motion records represent earthquakes with low, medium and high frequency contents. Three models were considered for the RC frames; bare frame, masonry-infilled frame with soft infill, and masonry-infilled frame with stiff infill. Four rehabilitation patterns were studied, namely: (1) introducing a RC shear wall, (2) using steel bracing, (3) using diagonal FRP strips (FRP bracings) in the case of masonry-infilled frames, and (4) wrapping or partially wrapping the frame members (columns and beams) using FRP composites. Incremental Dynamic Analysis was conducted for the studied cases. The seismic performance enhancement of the studied frames is evaluated in terms of the maximum applied peak ground acceleration resisted by the frames, maximum inter-storey drift ratio, maximum storey shear-to-weight ratio and energy dissipation capacity.     

高层建筑钢-混凝土混合结构简化分析模型

通过一定的等效原则将由外部钢框架、内部混凝土核心筒组成的高层混合结构简化为以下结构：钢框架简化为半刚架,混凝土核心简简化为具有箱形截面形式的竖向悬臂杆,再考虑几何非线性,用一列竖向受载杆与它们并联,从而得到简化计算模型,可用于该类建筑结构在水平荷载作用下的分析计算。     

海控国际广场外框型钢混凝土柱变更为钢管混凝土柱的设计与施工分析

钢管混凝土柱技术作为目前超高层钢结构建筑主要采用的结构形式,已日趋成熟,在各地的超高层建筑中得到广泛利用。海控国际广场A座原设计外框结构为型钢混凝土柱,后变更为矩形钢管混凝土柱。对比分析了型钢混凝土柱和钢管混凝土柱截面参数、受力特征、节点等设计和施工指标。对比结果证明钢管混凝土柱使结构受力更可靠,抗震性能更强,特别是减少了施工工序,施工更方便快捷。地上主体外框结构共计52层,钢结构施工工期仅280d,其中第31～50层达到3d/层的施工速度。实践证明,采用钢管混凝土柱,设计与施工方面均为最优方案,可取得较好的经济效益。     

钢管混凝土叠合柱结构施工技术

钢管混凝土叠合柱由截面中部钢管混凝土和钢管外侧钢筋混凝土叠合而成,东海商务中心（一期）工程两栋超高层办公楼为叠合柱结构体系,采用钢管贯通、翅片连接、钢管钢筋3种连接方式及RC环梁节点,技术先进,旆工快捷,取得了较好社会和经济效益。     

Reliability-based design method of suppressing chloride ingress for reinforced concrete buildings located in coastal regions of Taiwan

The main purpose of this work is to propose an estimating procedure that building designers can use to choose methods of suppressing chloride ingress, i.e. concrete-cover thickness, concrete-surface coating and concrete mix (water–cement ratio), for reinforced concrete (RC) buildings with a specified durability performance. At first, the authors build equations for estimating airborne chloride concentrations in coastal regions in Taiwan by regressing measurement data. Then, an analytical model incorporates these data into a deterioration model for chloride-induced corrosion and to estimate corrosion of reinforcing steel bars. This work also presents a novel computational procedure to calculate the risk of corrosion for reinforcing steel bars embedded in concrete, while considering uncertainties in environmental conditions, material properties and model error. Using risk curves of corrosion, building designers can set an allowable durable reliability to determine the minimal required concrete-cover thickness for RC members. Finally, this work adopts coastal regions in Taiwan as an example to determine the minimum required concrete-cover thicknesses. Furthermore, reliability-based methods of suppressing chloride ingress for RC buildings are also suggested for each division zone of Taiwan.     

Shaking table test and numerical simulation on a vertical hybrid structure under seismic excitation

A shaking table test of a 12‐story steel/reinforced concrete (S/RC) frame, which is composed of a 4‐story steel frame in the higher part, a 1‐story S/RC frame as a transition story in the middle part, and a 7‐story reinforced concrete (RC) frame in the lower part of the model, has been conducted, and its results are compared with those of a standard 12‐story RC frame to evaluate seismic performance of this S/RC frame. The numerical simulation on such hybrid frame structure has been performed and validated by the above experimental results. It is found that irregular lateral‐stiffness distribution along structural height will not only increase rotation at the joint of boundary between transition story and steel frame or concrete frame but also enlarge rotation at such joint and lead to more obvious rigid deformation in steel frame of S/RC frame, which will undoubtedly intensify bending failure. Meanwhile, acceleration response of the upper steel frame will reach its peak when characteristic site period is near the counterpart of the upper steel frame. Further, the maximum interstory drift under frequent earthquake excitation is at the lower substructure, namely, the RC frame, but this is not the case in rare earthquake situation. When it comes to determining damping ratio for vertical hybrid structure, a general method for engineering, which takes concrete and steel damping ratio for the whole structure analysis and then gets envelopes of these results for design, may yield conservative results. Meanwhile, such method may underestimate responses near the transition story.     

厚板转换层施工中若干问题的探讨

针对转换层在钢筋混凝土结构高层建筑中的重要性,对厚板转换层结构施工过程中关于模板工程、混凝土工程、钢筋工程以及预应力工程的若干重要问题进行了探讨,从而使厚板转换层结构得到更广泛的应用。     

瑞丰国际商务大厦高层钢结构制作与安装

瑞丰国际商务大厦是国内全部采用矩形钢管混凝土柱的高层钢结构建筑。详细介绍了工程的概况、施工过程中进行的新技术试验以及钢结构构件制作工艺和质量控制措施。介绍了安装施工中栓钉焊接和管内混凝土浇筑技术。通过实践和研究 ,积累了矩形钢管混凝土高层钢结构工程的施工经验     

Cost assessment of concrete and steel types for office buildings: An exploratory study

This paper presents a set of regression models which incorporates concrete and steel types in modeling the costs of office buildings. To these ends, three typical office buildings with seven and 15 stories have been designed by the help of a commercial software taking into account the Turkish practice. In each project C-16, C-20, C-25, C-30 and C-35 concrete classes and S-220 and S-420 steel types were used for dimensioning purposes. Rough construction costs were then calculated for different combinations of concrete classes and steel types. The findings of the study revealed that column dimensions decrease following an increase in a particular concrete class. However, this decrease stops after C-30. Furthermore, an average cost difference of 16% was observed between the steel types S-220 and S-420.