Dynamic response characteristics of super high-rise buildings subjected to long-period ground motions

Spectrum characteristics of different types of seismic waves and dynamic response characteristics of super high-rise building structures under long-period ground motions were comparatively analyzed. First, the ground response wave （named LS-R wave） of a soft soil site with deep deposit, taking long-period bedrock seismic record as input, was calculated by wave propagation method. After that, a TOMAKOMAI station long-period seismic record from the Tokachi-Oki earthquake and conventional E1-Centro wave were also chosen. Spectrum characteristics of these waves were analyzed and compared. Then, a series of shaking table tests were performed on a 1：50 scale super high-rise structural model under these seismic waves. Furthermore, numerical simulation of the prototype structure under these excitations was conducted, and structure damages under different intensive ground motions were discussed. The results show that： 1） Spectrum characteristics of ground response wave are significantly influenced by soft soil site with deep deposit, and the predominant period has an increasing trend. 2） The maximum acceleration amplification factor of the structure under the TOM wave is two times that under the E1-Centro wave; while the maximum displacement response of the structure under the TOM wave is 4.4 times that under the E1-Centro wave. Long-period ground motions show greater influences on displacement responses than acceleration responses for super high-rise building structures. 3） Most inelastic damage occurs at the upper 1/3 part of the super high-rise building when subjected to long-period ground motions.

Effects of high modes on the wind-induced response of super high-rise buildings

For super high-rise buildings, the vibration period of the basic mode is several seconds, and it is very close to the period of the fluctuating wind. The damping of super high-rise buildings is low, so super high-rise buildings are very sensitive to fluctuating wind. The wind load is one of the key loads in the design of super high-rise buildings. It is known that only the basic mode is needed in the wind-response analysis of tall buildings. However, for super high-rise buildings, especially for the acceleration response, because of the frequency amplification of the high modes, the high modes and the mode coupling may need to be considered. Three typical super high-rise projects with the SMPSS in wind tunnel tests and the random vibration theory method were used to analyze the effect of high modes on the wind-induced response. The conclusions can be drawn as follows. First, for the displacement response, the basic mode is dominant, and the high modes can be neglected. Second, for the acceleration response, the high modes and the mode coupling should be considered. Lastly, the strain energy of modes can only give the vibration energy distribution of the high-rise building, and it cannot describe the local wind-induced vibration of high-rise buildings, especially for the top acceleration response.

Discussion on the Construction of Anti-smoke Construction Technology in Super High-rise Buildings

In recent years with the increasing number of super high-rise buildings and the ever-expanding scale the anti-smoke construction technology has attracted more and more attention.Based on this situation,this paper analyzes the smoke control technology of super high-rise buildings.The paper analyzes the importance of the application of anti-smoke construction technology in super high-rise buildings,analyzes the problems in the construction of smoke control and super high-rise buildings.The anti-smoke construction technology was studied and I hope that it can benefit the application of anti-smoke construction technology in high-rise buildings.

Collapse simulation of a super high-rise building subjected to extremely strong earthquakes

In recent years, super high-rise buildings (>500 m) are developing very quickly and become an important frontier of civil engineering. The collapse resistance of super high-rise buildings subjected to extremely strong earthquake is a critical problem that must be intensively studied. This paper builds up a nonlinear finite element model of the tallest building in China, Shang- hai Tower (632 m), and proposes the modeling method and failure criteria for different structural elements. The dynamic char- acters of this building are then analyzed, and the possible failure modes and collapse processes due to earthquakes are pre- dicted, as well as the corresponding collapse mechanism. This work will be helpful in collapse prevention and the seismic design of super high-rise buildings.

An improved ground motion intensity measure for super high-rise buildings

Ground motion intensity measure (IM) is an important part in performance-based seismic design. A reasonable and efficient IM can make the prediction of the structural seismic responses more accurate. Therefore, a more reasonable IM for super high-rise buildings is proposed in this paper. This IM takes into account the significant characteristic that higher-order vibration modes play important roles in the seismic response of super high-rise buildings, as well as the advantages of some existing IMs. The key parameter of the proposed IM is calibrated using a series of time-history analyses. The collapse simulations of two super high-rise buildings are used to discuss the suitability of the proposed IM and some other existing IMs. The results indicate that the proposed IM yields a smaller coefficient of variation for the critical collapse status than other existing IMs and performs well in reflecting the contribution of higher-order vibration modes to the structural response. Hence, the proposed IM is more applicable to seismic design for super high-rise buildings than other IMs.

基于大涡模拟的CAARC模型角区开槽气动优化研究

超高层建筑属风敏感结构,对建筑外形进行适当气动优化可有效降低结构风荷载及风致响应。基于大涡模拟(LES)方法,采用一种新的入口湍流生成方法——NSRFG(narrow-band synthesis random flow generation)方法,进行超高层建筑标准模型(CAARC)角区开槽的气动优化研究。首先进行了CAARC高层建筑标准模型绕流模拟,并将模拟结果与风洞试验结果对比,以验证NSRFG方法的适用性;然后以CAARC模型为基础,设计了4种开槽气动优化方案,通过LES模拟得到基底弯矩功率谱,以估算建筑顶部位移响应和顶部峰值加速度响应。结果对比显示:对于矩形截面高层建筑标模,无论原型还是4种开槽气动优化方案,横风向脉动响应和峰值加速度响应整体比顺风向大;与全封闭原型相比,采取不同开槽方案均能降低顺风向和横风向风振响应,其中角区开槽对顺风向响应的优化效果最好,周向开槽对横风向响应的优化效果最好;4种开槽方案对于横风向响应的优化效果明显优于顺风向,其中相对而言周向开槽优化效果相对最好,使横风向脉动位移响应和横风向峰值加速度响应分别降低28.4%、32.8%。因此,从减小矩形截面超高层建筑结构横风向响应角度考虑,建议采用周向开槽方案。

桥梁超高墩数字造墩机应用研究

超高墩大跨度桥梁作为地形起伏不定、高低落差较大地区的一种重要解决方案,其施工技术的发展起到了举足轻重的作用。文章依托在建渝湘复线高速公路项目龙川江特大桥工程超高墩施工,对桥梁超高墩在施工过程中普遍采用的传统液压爬模结构功能性单一、竖直度控制精度不足、智能化程度低等一系列问题进行了深入的剖析,成功研制了一种新型桥梁超高墩数字造墩机,实现了内外模同步爬升、状态实时监测、形位尺寸自动调节等功能,保证了桥墩的成型精度和质量,提高了施工效率,保障了施工安全。

软土地区超高层建筑岩土工程关键问题及沉降控制研究

以上海中心大厦为例,对软土地区超高层建筑桩型选择、桩基承载力计算、沉降计算参数取值及沉降计算等岩土工程关键技术问题进行了总结和研究。超高层荷载大,对桩基承载力要求高,桩型选择需结合周边环境、桩基承载力要求、施工可行性等因素综合考虑后确定,软土地区超高层建筑采用后注浆大直径超长灌注桩是适宜的。超高层建筑基础沉降要求高,需结合地层条件、结构特点、荷载分布情况、周边环境等因素综合考虑,确定沉降计算参数及计算方法。经采用多种计算方法进行沉降预测,塔楼沉降量估算值为75~120 mm,最终实测总沉降量约100 mm,有限元法的预测结果与实测值更为吻合,其中结构封顶时沉降量占最终沉降量的90%左右,沉降变形主要发生在工程建设期间。

装饰条干扰下超高层建筑表面风压系数及风荷载体型系数研究

为解决因幕墙装饰条对超高层建筑外表面风压分布造成干扰使其分布不均衡导致的装饰条掉落问题,基于Davenport脉动风速功率谱及拟合函数、LES湍流模型和《建筑结构荷载规范》(GB 50009—2012)的推荐计算公式,利用计算流体动力学方法对装配不同型号装饰条的超高层建筑进行三维风场流体模拟。研究了超高层建筑及装饰条自身表面的风压分布特征和装饰条风荷载体型系数随其横截面体型特征及布置间距变化的规律。结果表明:超高层建筑外表面平直区域风压极值增高,拐角过渡区域风压极值降低,配置装饰条能够改善建筑表面拐角区域风压突变现象;当装饰条横截面为矩形时,其正侧表面的风荷载体型系数随截面高度增大而增大,横截面为梯形时,其侧表面的风荷载体型系数随下底的减小而减小,风荷载体型系数随装饰条间距变化的趋势不明显。

天安云谷产业园公寓楼超限高层结构设计

天安云谷公寓楼项目因功能需求,存在高度超限、扭转不规则、楼板不连续(开大洞口)、竖向抗侧力构件不连续等不规则情况。采用SATWE、YJK软件对结构进行多遇地震和风荷载作用下的计算分析,采用PERFORM 3D软件进行罕遇地震作用下的结构动力弹塑性时程分析,得到了结构计算的主要分析指标。通过各阶段的结构分析可知,本工程能实现设定的整体抗震性能目标预期,小震、中震、大震时均能达到C级抗震性能目标,结构设计合理、安全、可靠。

特大型博物馆建筑火灾场景模拟及消防安全性分析研究

特大型博物馆建筑作为综合性和专业性很强的建筑类型,在设计过程中需综合考虑的因素颇多,消防工程便是其中之一。根据其使用功能和空间布局等特性,设计中往往存在现行规范未涵盖或允许适当扩大、或需采用新技术的问题。因此,须进行特殊消防设计并加以论证。在火灾发生时,应全面考虑文物存储与保护、观众安全与疏散、设备控制与损失,降低运行干扰等情形。为保证设计的科学性和可行性,进行火灾场景模拟和消防安全性分析是必要且重要的。本文以故宫博物院北院区项目为例,详细阐述了火灾模拟与消防安全性分析的技术路线,主要包括火灾设计、火灾场景设置、疏散场景设置、人员疏散模拟分析、烟气模拟分析及安全性判定等内容。通过项目研究可为同类型建筑的此类问题提供技术路线参考。

锚杆静压钢护筒挖孔桩工艺在超高层基础加固工程中的应用

依托某超高层建筑基础加固工程实例,阐述了原桩基状况,归纳总结该工程特点和难点,并针对工程难点进行方案选型探讨。通过现场试验和理论计算,验算了大直径锚杆静压钢护筒挖孔桩的单桩承载力。采用变刚度桩迭代法对桩基刚度进行迭代计算,使后补桩基与原桩基实现变形协调。研究结果表明:所提出的锚杆静压钢护筒与人工挖孔结合方法,解决了该工程基础加固施工风险难题;桩基检测和后期沉降观测数据说明,锚杆静压钢护筒挖孔桩工艺不仅施工质量可控,而且基础加固效果明显,为处理类似超高层建筑基础加固问题提供了新思路。

某中庭大开洞超B级复杂高层结构设计与分析

某办公楼,房屋高度为198.85 m,采用框架-核心筒结构体系,属于超B级高度的超限高层。为此,在建筑方案设计阶段,尽量减少平面和竖向不规则项。但由于建筑采光及通风需要,中庭采用比较少见的通高开大开洞平面布置形式,并在洞口四周布置剪力墙,形成核心筒内筒,同时针对中庭大开洞影响,进行多方案计算比较分析。在结构设计过程中,使用两种不同的计算软件进行小震作用下弹性计算分析,并对计算结果进行对比分析。综合各种因素,抗震性能目标取为C级,按照C级目标进行中震、大震下分析计算。依据大震下主体结构的具体损伤情况,对薄弱部位采取加强措施。计算结果表明,关键构件均能达到预先设定目标,结构安全可靠,可为同类型项目结构设计提供思路和参考。

扩声系统在大型体育场馆安装施工技术

国家速滑馆是全冰面大型体育场馆,作为2022年北京冬奥会速度滑冰比赛场馆,扩声系统在比赛过程中有着至关重要的作用。针对不同体育比赛类型对扩声系统的要求,结合超大建筑空间以及整体冰面的声音环境特点,扩声系统可以满足不同比赛形式、观众规模和使用功能的需求。通过不同场景的设置与调试,确保国家速滑馆扩声系统各项声学指标达到国家一级标准。整个系统的语言声音清晰、音乐解析度佳、响度和平衡感足够。

超大直径盾构隧道穿越并列布置建筑群影响分析

以上海市超大直径盾构隧道北横通道下穿建筑群工程为研究背景,采用数值模拟和现场监测相结合的方法,对隧道穿越过程中建筑沉降进行分析,并在此基础上根据现场建筑排列特点建立并列布置建筑群,通过设计4种不同穿越工况,研究盾构穿越建筑群时地表沉降和隧道上方单幢建筑沉降受周围建筑影响规律。研究结果表明:侧穿区域内建筑对地表沉降曲线影响较小,下穿区域内建筑引起地表沉降曲线呈现非对称“V”形;建筑群对地表沉降主要影响区域为隧道轴线两侧2D范围,施工过程中应对该范围进行重点监测;侧穿区域内建筑对隧道轴线另一侧建筑沉降有抑制作用,下穿区域内的建筑对隧道上方建筑扰动较大;隧道穿越建筑前,纵向方向的建筑群对该建筑的隆起变形有抑制作用,穿越后,纵向方向的建筑群对该建筑的沉降影响更大;建筑纵向倾斜率随盾构开挖进程变化较大,盾构穿越过程中应重点关注建筑纵向倾斜变化。

孔内深层超强夯工法在湿陷性黄土地区高层建筑地基处理中的应用

为探讨孔内深层超强夯(SDDC)工法在湿陷性黄土地区的应用效果,采用SDDC工法的大直径挤密桩作为某高层建筑地基处理方法,进行复合地基承载力静载荷试验、桩体压实系数和桩间土挤密系数试验、桩身强度试验;依据试验数据指标,按桩身强度和复合地基承载力特征值双控的方法,确定复合地基承载力,并对建筑物在施工期间沉降和竣工后沉降观测数据进行搜集对比。试验结果表明,SDDC工法在湿陷性黄土地区高层建筑地基处理中消除地基湿陷、提高地基承载力、减小基础沉降、加快施工速度、提高施工质量和经济效益等方面具有明显优势,表明该方法在湿陷性黄土地区处理地基是有效可行的。

超大城市综合体建筑防火设计与消防安全管理分析

介绍了超大城市综合体建筑中火灾的特点,强调以实际情况为基础进行合理的防火设计,同时提出符合实际的消防安全管理工作建议,促使超大城市综合体建筑中的防火设计更加优化,内部消防安全管理水平进一步提升。

郑州国际文化交流中心酒店结构设计

郑州国际文化交流中心酒店地上9层,地下2层,地上分为A区、B区两个结构单元,均为复杂超限高层建筑。主体结构均采用钢筋混凝土框架-剪力墙体系,关键部位采用型钢混凝土或全钢结构。A区有跨度为23.7~25.3m的弧形转换,采用弧形型钢混凝土转换梁;B区在3层~屋面有11.3m的超长悬挑,采用双层斜拉杆体系。分析了结构整体性能,明确了结构关键部位,选取并验证了中震、大震下的性能化目标,采用大震弹塑性时程分析揭示了结构薄弱部位并采取了针对性措施。专项分析了弧形转换梁的抗扭能力和应力分布,超长悬挑区的楼板作用、节点应力、抗连续倒塌能力,并提出了加强措施。分析结果表明,结构设计满足规范要求,并具有良好的抗震性能。

多边曲线超大穿孔装饰铝板的安装技术

为更好地进行铁路客站多边曲线超大穿孔装饰铝板的施工,对比了几种常见的高铁站房吊顶施工安装方式,并研发出一种无架体反吊顶安装技术。利用主流建筑信息模型技术结合地面预拼装和单元块整体安装的方式,优化拱弧形穿孔三角铝板吊顶安装施工方法,增补吊顶造型样式,总结的经验可为今后高铁车站等公共空间多边曲线吊顶施工提供经验参考。

超大吨位锚杆静压桩加固超高层建筑实践

由于建筑设计调整,广东省某超高层桩基建筑物上部重量大幅增加,远超原设计对基础承载力的要求,需要对基础进行加固。根据工程情况,选用锚杆静压钢管桩加固方案,但压桩动阻力高达6000kN,沉桩难度大,且类似超大吨位锚杆静压桩工程实践鲜见报道,没有可参照的工程做法。克服地质条件复杂、施工条件局限等困难,创新采用8000kN重型桩架、8000kN大型千斤顶以及减摩助沉方法,经济合理地完成了桩基础加固施工。此超高层补桩基础加固实践为广东省首例,可为同类型建筑物加固提供宝贵经验,能带来可观的经济效益和社会效益。