基于阻尼器反力墙体系的特大型LNG储罐控制研究

特大型液化天然气（LNG）储罐的固有频率通常介于2~10 Hz之间,处于大部分地震运动的频率范围之内。在过去的几十年中,许多事故已经证明,储罐在地震作用下很容易遭破坏。使用隔震支座来减少储罐的地震作用已经被证明是非常有效的,但对于特大型LNG储罐,其连接组件对隔震层层间位移有严格限制,尤其是在软土场地中,桩水平抗力与隔震层位移是一对矛盾,普通隔震系统会在隔震层产生较大位移,导致特大型LNG储罐连接组件的设计非常困难。因此提出了一种由环形阻尼器反力墙、粘滞阻尼器以及安装于基桩顶端的隔震支座组成的新型隔震系统,反力墙独立设置于地基中,不与桩基连接,罐底的部分剪力直接向反力墙传递。以容量为16万m3的特大型LNG储罐为例,建立多自由度集中质量简化模型,以层间位移、桩基剪力作为性能指标进行了评价分析。结果显示,新型隔震系统对特大型LNG储罐隔震层位移及桩基剪力的控制非常有效。     

不同再生骨料掺量的中高剪力墙振动台试验研究

为了研究再生混凝土剪力墙的动力性能,进行了3个1/3缩尺的不同再生骨料取代率的中高剪力墙模型的模拟地震振动台试验,其中1个为普通混凝土剪力墙、1个为再生粗骨料混凝土剪力墙、1个为全再生骨料混凝土剪力墙。试验过程经历了剪力墙弹性、开裂和破坏阶段,实测并比较分析了各剪力墙在不同阶段的动力特性、动力反应及破坏形态。试验结果表明:再生粗骨料混凝土中高剪力墙具有和普通混凝土剪力墙相近的抗震性能,其墙体开裂时台面加速度输入降低9.7%,其弹塑性位移角达到1/120时台面加速度输入降低5.8%,经合理设计,可用于建筑结构。     

Assessment of seismic design response factors of concrete wall buildings

To verify the seismic design response factors of high-rise buildings, five reference structures, varying in height from 20- to 60-stories, were selected and designed according to modern design codes to represent a wide range of concrete wall structures. Verified fiber-based analytical models for inelastic simulation were developed, considering the geometric nonlinearity and material inelasticity of the structural members. The ground motion uncertainty was accounted for by employing 20 earthquake records representing two seismic scenarios, consistent with the latest understanding of the tectonic setting and seismicity of the selected reference region (UAE). A large number of Inelastic Pushover Analyses (IPAs) and Incremental Dynamic Collapse Analyses (IDCAs) were deployed for the reference structures to estimate the seismic design response factors. It is concluded that the factors adopted by the design code are adequately conservative. The results of this systematic assessment of seismic design response factors apply to a wide variety of contemporary concrete wall buildings with various characteristics.     

Experimental research on the seismic behavior of CSPSWs connected to frame beams

The seismic performance of composite steel plate shear walls (CSPSWs) that consist of a steel plate shear wall (SPSW) with reinforced concrete (RC) panels attached to one or both sides by means of bolts or connectors is experimentally studied. The shear wall is connected to the frame beams but not to the columns. This arrangement restrains the possible out-of-plane buckling of the thin-walled steel plate, thus significantly increasing the bearing capacity and ductility of the overall wall, and prevents the premature overall or local buckling failure of the frame columns. From a practical viewpoint, these solutions can provide open space in a floor as this type of composite shear walls with a relatively small aspect ratio can be placed parallel along a bay. In this study, four CSPSWs and one SPSW were tested and the results showed that both CSPSWs and SPSW possessed good ductility. For SPSW alone, the buckling appeared and resulted in a decrease of bearing capacity and energy dissipation capacity. In addition, welding stiffeners at corners were shown to be an effective way to increase the energy dissipation capacity of CSPSWs.     

GPS在水准测量粗差检测中的应用

本文介绍了水准测量粗差产生的原因及检查方法,通过GPS在水准测量粗差检测中的应用实例分析,说明了使用GPS技术能提高水准测量的效率。     

汶川地震中强震动相对持时的空间变化特性研究

使用70％和90％能量持时定义,计算了汶川Ms8.0大地震中获取的来自109个台站强震动加速度记录的相对持时,并以此在竖向及两个水平向上分别进行了回归统计分析,得到了地震动持时的空间变化关系,给出了适合汶川地震地震动的持时定义.对比分析了上盘和下盘2个区域持时空间变化特征,进一步计算了地震动竖向持时与两个水平向持时的比...     

西藏甲玛铜多金属矿床围岩蚀变特征及成矿流体运移规律浅析

甲玛铜多金属矿床围岩蚀变发育,可分为四期八个阶段,其中矽卡岩化、绢英岩化与成矿时空关系密切。通过对绢英岩化蚀变岩的质量平衡计算发现,导致绢英岩化围岩蚀变的热液为晚期岩浆分异的富挥发份的含矿硅质富钾酸性流体;并随着蚀变的发生发展,蚀变岩的主元素及成矿元素显示不同的迁移规律但表现出相似的蚀变流体运移趋势,即:以则古郎地区为中心,分别向铜山、铅山及莫古郎地区运移,由于铜山滑覆体阻挡,使得铜山地区蚀变较强,莫古郎地区较弱。     

豫东地区中深孔厚覆盖地层钻探套管护壁和泥浆护壁效果对比

阐述了河南省新蔡县焦庄铁矿预查钻孔施工工艺和河南省睢县煤矿预查太康县煤孔施工工艺,通过对比2个矿区施工的经验教训,分析了套管护壁和泥浆护壁在豫东地区的适应性。     

CY-1钻孔盐水泥浆护壁技术

CY-1钻孔是河北沧县盐矿深部勘探的第一钻,在钻探施工中,泥浆护壁是遇到的技术难题之一。针对工区施工条件采用了分段泥浆转换方案,确保了施工安全及质量。实践表明,该钻孔泥浆护壁方法技术路线可行,实现了顺利取心,为沧州地区深部盐矿勘探积累了经验。详细介绍了该孔盐水泥浆护壁技术。     

利用 FLAC 3D 对基坑支护数值模拟分析

FLAC 3D 是岩土工程中广泛应用的软件。本文以某地区基坑为背景,进行土钉墙支护设计,并利用 FLAC 3D 软件对土钉墙支护前后进行数值模拟。在基坑开挖完成后,边墙位移一般为 20 ～ 40 cm,最大位移为 45 cm。采用土钉墙支护后,边墙的位移为 2 ～ 4 cm,最大位移为 6 cm。对比表明,土钉墙支护能够有效的阻止基坑的变形,维持基坑的稳定。同时,根据土钉的轴力分布特征,分析基坑在不采取支护措施的情况下将发生滑移破坏。