应用综合物探法勘查评价抚顺榆林局部塌陷区     

高飞  张立军 《地质与资源》2001,10(2):116-118

利用测地工作、重力测量、高精度磁测、甚低频电磁法、电测深测量、浅层地震折射波法等物探方法,勘查评价了抚顺榆林局部塌陷区.利用物探方法可查明本区内的断裂构造、地下空洞、含水层位的分布情况,并综合所有物探成果及地质、地形测量工作成果进行推断解释.研究了该塌陷区沉降与塌陷的机理,总结塌陷原因,指出塌陷隐患部位.  相似文献   

隧道围岩破坏模式的进化神经网络识别   总被引：5，自引：1，他引：4  

高玮  杨明成  郑颖人 《岩土力学》2002,23(6):691-694

隧道围岩破坏受很多因素的影响,其破坏模式的识别是一个复杂的非线性系统辨识问题,采用一般方法很难得到好的解答。基于作者提出的免疫进化规划,并把它同神经网络(NN)相结合,提出了一种全新的结构及权值同时进化的进化神经网络(ENN)模型,用于围岩破坏模式的识别研究,用一个试验算例证明了进化神经网络具有解决此问题的良好性能。  相似文献   

无线电波坑透探测在大同煤田的应用研究     

李兰亭  侯吉祥 《煤田地质与勘探》2001,29(5):52-55

通过大同煤田大量的坑透探测工作,总结了断层、陷落柱在坑透中的曲线特征,并例举分析了测区坑透资料及采后验证情况。实践证明,坑透探测必须经过大量的验证工作总结经验,才能使此技术在大同煤田得到准确的应用。   相似文献   

Aseismic Reliability Analysis Approach for Offshore Jacket Platform Structures   总被引：1，自引：0，他引：1  

ZHUANG Yizhou  JIN Weiliang Post-doctor 《中国海洋工程》1998,(4)

—By means of nonlinear pushover collapse analysis approach,the aseismic reliability analysesof two offshore jacket platforms in the Bohai Gulf in China are studied according to their ocean locationand environmental loadings there.On the basis of those analyses,an aseismic reliability analysis approachis presented.The results show that the aseismic reliability of those platforms is high.Also it is proved thatthis aseismic reliability analysis approach is simple,practical and reliable.  相似文献   

柔性管道骨架层压溃失效机理和安全评价方法研究进展     

陈严飞  刘昊  孙伟栋  董绍华  覃雯琪  高莫狄  马尚 《海洋工程》2021,39(4):154-162

非黏结柔性管道作为深水油气开发领域的关键设备,是连接海底井口和海洋平台的主要纽带。海洋油气开发水深已经超过了3 000 m,高静水压力是深水软管设计和安全评价的主要挑战,明确深水柔性管道压溃失效机理,并准确地预测柔性管道的压溃压力可以为柔性管道结构设计和安全评价提供依据,柔性管道的压溃压力与骨架层的几何形状以及骨架层之间复杂的相互作用有关,准确高效地预测压溃压力变得极具挑战性。针对柔性管道失效机理研究和压溃压力预测方法进行了总结,指出当前柔性管道压溃失效分析中薄弱的环节,为我国非黏结柔性管道的结构设计和安全评价提供参考。  相似文献   

Integrating visual damage simulation,virtual inspection,and collapse capacity to evaluate post‐earthquake structural safety of buildings          下载免费PDF全文

Henry V. Burton  Gregory G. Deierlein 《地震工程与结构动力学》2018,47(2):294-310

A methodology is introduced to assess the post‐earthquake structural safety of damaged buildings using a quantitative relationship between observable structural component damage and the change in collapse vulnerability. The proposed framework integrates component‐level damage simulation, virtual inspection, and structural collapse performance assessment. Engineering demand parameters from nonlinear response history analyses are used in conjunction with component‐level damage simulation to generate multiple realizations of damage to key structural elements. Triggering damage state ratios, which describe the fraction of components within a damage state that results in an unsafe placard assignment, are explicitly linked to the increased collapse vulnerability of the damaged building. A case study is presented in which the framework is applied to a 4‐story reinforced concrete frame building with masonry infills. The results show that when subjected to maximum considered earthquake level ground motions, the probability of experiencing enough structural damage to trigger an unsafe placard, leading to building closure, is more than 2 orders of magnitude higher than the risk of collapse.  相似文献   

不规则性对基础隔震结构抗连续倒塌性能影响研究          下载免费PDF全文

包超  张尚荣  马肖彤  杜永峰  张立新 《地震工程学报》2018,40(3):480-489

为研究基础隔震结构抗连续倒塌性能,以备用荷载路径法为基础,采用静力非线性Pushdown方法和静力线性方法对一栋典型的收进式竖向不规则钢筋混凝土基础隔震结构进行分析,从备用荷载路径的抗连续倒塌机制和需求能力比两个角度研究竖向不规则钢筋混凝土基础隔震结构的抗连续倒塌性能,为基础隔震结构抗连续倒塌设计提供参考;为进一步研究结构布置形式不规则性以及裙楼和塔楼层数变化对竖向不规则基础隔震抗连续倒塌性能的影响,分别建立塔楼布置不同、裙楼与塔楼层数变化的模型进行对比研究。研究表明:除角柱失效工况自身无法产生悬链线机制外,其余底层框架柱失效工况中备用荷载路径在整个推覆倒塌过程中均表现出明显的悬链线机制;当隔震支座失效时,由于隔震层水平刚度小,相邻支座无法提供足够的侧向约束作用而难以形成明显的悬链线机制;增加结构冗余度和备用荷载路径中参与荷载传递的构件数量可以有效提高剩余结构抗连续倒塌能力;除角柱和角支座外,隔震支座失效工况DCR值普遍大于对应位置底层框架柱失效工况,备用荷载路径中某些构件的失效风险相对较大。  相似文献   

竖向刚度不同的混合结构连续倒塌机制分析          下载免费PDF全文

林健康  杨文伟  包超 《地震工程学报》2018,40(4):713-720,840

为了探究上部钢结构-下部混凝土结构这类竖向刚度不同的混合结构抗连续倒塌机制,利用拆除构件法,应用ANSYS/LS-DYNA对初始失效后的剩余结构进行非线性静力(Pushdown方法)分析,研究其剩余结构的倒塌破坏模式、荷载变形关系,以及初始失效柱位置的不同和钢框架层数对结构抗连续倒塌性能的影响。结果表明:剩余结构的倒塌破坏模式带有典型的延性变形特征,且在倒塌过程中出现位移和应力分布不连续现象;除边柱失效后剩余结构的倒塌过程仅经历了梁机制外,其余剩余结构的倒塌过程均经历了梁机制、压拱机制和悬链线机制;剩余结构的竖向承载力与初始失效柱高度呈负相关,与钢框架层数呈正相关;为剩余结构提供足够的侧向约束作用以及提高结构冗余度和备用荷载路径数量,可以有效提高剩余结构的抗连续倒塌能力。  相似文献   

隔震防倒塌支座及楼梯间位置对框架结构抗震性能的影响研究          下载免费PDF全文

常亚峰  梁兴文  汪平  辛力 《地震工程学报》2017,39(6):996-1004

为研究梯段板下端设置隔震防倒塌支座和楼梯间位置对钢筋混凝土框架结构抗震性能的影响,利用ETABS软件建立不包括、包括隔震防倒塌支座的3种楼梯间布置方案,6个框架结构计算模型。通过模态分析、反应谱分析和Pushover分析,研究隔震防倒塌支座和楼梯间位置对框架结构的振型、内力及破坏机制的影响。结果表明:梯段板下端设置隔震防倒塌支座后,楼梯间位置对钢筋混凝土框架结构的扭转效应影响较小,且框架结构在两个主轴方向的动力特性比较接近;楼梯间框架柱内力均显著降低,但楼梯间布置在最边跨时,在垂直于梯跑方向地震作用下,框架结构边柱内力较大;框架梁对整体框架结构的耗能贡献较多,增强了框架结构的抗震性能,大震时楼梯构件严重破坏较晚,设置隔震防倒塌支座可保证楼梯整体稳定性。  相似文献   

The role of ground motion duration and pulse effects in the collapse of ductile systems     

Maria Liapopoulou  Miguel A. Bravo-Haro  Ahmed Y. Elghazouli 《地震工程与结构动力学》2020,49(11):1051-1071

The seismic collapse capacity of ductile single-degree-of-freedom systems vulnerable to P-Δ effects is investigated by examining the respective influence of ground motion duration and acceleration pulses. The main objective is to provide simple relationships for predicting the duration-dependent collapse capacity of modern ductile systems. A novel procedure is proposed for modifying spectrally equivalent records, such that they are also equivalent in terms of pulses. The effect of duration is firstly assessed, without accounting for pulses, by assembling 101 pairs of long and short records with equivalent spectral response. The systems considered exhibit a trilinear backbone curve with an elastic, hardening and negative stiffness segment. The parameters investigated include the period, negative stiffness slope, ductility and strain hardening, for both bilinear and pinching hysteretic models. Incremental dynamic analysis is employed to determine collapse capacities and derive design collapse capacity spectra. It is shown that up to 60% reduction in collapse capacity can occur due to duration effects for flexible bilinear systems subjected to low levels of P-Δ. A comparative evaluation of intensity measures that account for spectral shape, duration or pulses, is also presented. The influence of pulses, quantified through incremental velocity, is then explicitly considered to modify the long records, such that their pulse distribution matches that of their short spectrally equivalent counterparts. The results show the need to account for pulse effects in order to achieve unbiased estimation of the role of duration in flexible ductile systems, as it can influence the duration-induced reduction in collapse capacity by more than 20%.  相似文献