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41.
平扭耦联隔震体系的简化模型及有关参数变化的计算分析 总被引:5,自引:1,他引:5
李向真 《地震工程与工程振动》2005,25(3):163-166
本文根据隔震结构的动力学特点,提出了空间平扭耦联隔震结构简化计算模型,该模型仅有四个自由度,做定性分析和近似计算十分方便,力学概念明确可靠,文中并对这种体系的动力特性和反应,采用反应谱方法进行分析计算。还对平扭耦联隔震结构的重要特征参数对结构的动力特性和动力反应的影响,进行了较为全面的分析研究。 相似文献
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In the work reported here the comprehensive physics‐based Integrated Hydrology Model (InHM) was employed to conduct both three‐ and two‐dimensional (3D and 2D) hydrologic‐response simulations for the small upland catchment known as C3 (located within the H. J. Andrews Experimental Forest in Oregon). Results from the 3D simulations for the steep unchannelled C3 (i) identify subsurface stormflow as the dominant hydrologic‐response mechanism and (ii) show the effect of the down‐gradient forest road on both the surface and subsurface flow systems. Comparison of the 3D results with the 2D results clearly illustrates the importance of convergent subsurface flow (e.g. greater pore‐water pressures in the hollow of the catchment for the 3D scenario). A simple infinite‐slope model, driven by subsurface pore‐water pressures generated from the 3D and 2D hydrologic‐response simulations, was employed to estimate slope stability along the long‐profile of the C3 hollow axis. As expected, the likelihood of slope failure is underestimated for the lower pore pressures from the 2D hydrologic‐response simulation compared, in a relative sense, to the higher pore pressures from the 3D hydrologic response simulation. The effort reported herein provides a firm quantitative foundation for generalizing the effects that forest roads can have on near‐surface hydrologic response and slope stability at the catchment scale. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
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四平地区矿产资源以非金属为主,硅灰石、石灰石、硅砂、膨润土、伊利石、天然气等矿种储量位居吉林省同类矿种前列。本文通过对国内外非金属矿开发利用的调查研究,对本区非金属矿深加工及开发方向做了进一步探索,提出了可供政府决策的观点,只有做好非金属矿产深加工工作,四平矿业经济的跨越式发展才会有坚实的基础。 相似文献
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地下工程震波技术与应用 总被引:11,自引:0,他引:11
激发的震波在工程岩土体中传播,检测其波动力学参数,来测试岩土体的工程力学性质。原位震波波速测试技术可以对井巷的岩体模量,支护选型,围岩性质进行检测;利用地震勘探,面波勘探方法可以对矿层厚度,超前探测等方面进行有效检测;震波CT、导波勘探等探测方法对于采面内的地质异常探测有较好的针对性;通过声发射检测技术可以解决地下工程安全问题。实际应用说明,震波探测技术从地下工程的开拓掘进,采场形成到采后管理等过程中有着广泛的应用前景。一些技术已作为地下工程中的日常工作加以应用,但进一步的生产应用还需深入研究。 相似文献
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During the early Middle Devonian in South China, an extensive carbonate platform was broken up through extension to create a complex pattern of platforms, and interplatform basins. In Givetian and Frasnian carbonate successions, five depositional facies, including peritidal, restricted shallow subtidal, semi‐restricted subtidal, intermediate subtidal and deep subtidal facies, and 18 lithofacies units are recognized from measured sections on three isolated platforms. These deposits are arranged into metre‐scale, upward‐shallowing peritidal and subtidal cycles. Nine third‐order sequences are identified from changes in cycle stacking patterns, vertical facies changes and the stratigraphic distribution of subaerial exposure indicators. These sequences mostly consist of a lower transgressive part and an upper regressive part. Transgressive packages are dominated by thicker‐than‐average subtidal cycles, and regressive packages by thinner‐than‐average peritidal cycles. Sequence boundaries are transitional zones composed of stacked, high‐frequency, thinner‐than‐average cycles with upward‐increasing intensity of subaerial exposure, rather than individual, laterally traceable surfaces. These sequences can be further grouped into catch‐up and keep‐up sequence sets from the long‐term (second‐order) changes in accommodation and vertical facies changes. Catch‐up sequences are characterized by relatively thick cycle packages with a high percentage of intermediate to shallow subtidal facies, and even deep subtidal facies locally within some individual sequences, recording long‐term accommodation gain. Keep‐up sequences are characterized by relatively thin cycle packages with a high percentage of peritidal facies within sequences, recording long‐term accommodation loss. Correlation of long‐term accommodation changes expressed by Fischer plots reveals that during the late Givetian to early Frasnian increased accommodation loss on platforms coincided with increased accommodation gain in interplatform basins. This suggests that movement on faults resulted in the relative uplift of platforms and subsidence of interplatform basins. In the early Frasnian, extensive siliceous deposits in most interplatform basins and megabreccias at basin margins correspond to exposure disconformities on platforms. 相似文献
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以HDR隔震梁桥多自由度(MDOF)模型和等效双线性单自由度(SDOF)模型为研究对象,以典型近场地震动作为输入,研究HDR支座双向耦合效应对HDR隔震梁桥地震响应的影响。研究结果表明:不考虑双向耦合效应的HDR支座滞回曲线呈典型双线性;考虑双向耦合效应的HDR支座滞回曲线面积小于不考虑双向耦合效应的HDR支座滞回曲线面积。不考虑双向耦合效应的顺桥向HDR支座位移峰值db大于考虑双向耦合效应时,但横桥向的结果相反。近场地震作用下,对梁桥进行HDR支座隔震设计时,忽略双向耦合效应计算得到的墩底剪力峰值和弯矩峰值均偏于保守。可忽略HDR支座双向耦合效应对HDR隔震梁桥近场地震能量的影响。 相似文献
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以地球物理勘探方法进行隧道掘进中前方岩石结构的超前预报,具有快捷、准确和实时处理及显示的优点。通过该方法可及时、详细地了解开挖掌子面前方岩石结构情况,为施工单位合理安排施工进度和减少工程隐患提供依据。以吉林省白山市石碑岭隧道掘进中所进行的超前预报为例,介绍了地质雷达和地震反射波法在这一领域里的应用。 相似文献