关于地下断层封闭性的讨论——以东营凹陷为例   总被引：25，自引：0，他引：25  

王志欣  信荃麟 《高校地质学报》1997,3(3):293-300

本文回顾并分析了前人进行断层封闭性评价的一些基本思路,并根据孔隙压力和有效应力原理提出了断层封闭性评价的新见解,断面的力学性质取决于该断面上有效直应力和剪应力的大小和方向;有效直应力为压性,则断面为封闭的,有效直应力的性质受控于有效地应力,而有效地应力的大小与流体压力密切相关;以前对断层封闭性的评价中所考虑的影响因素是不全面的,完全忽略了流体压力对断层封闭性的影响;断层封闭性不但是变化的,而且其变化是一种瞬时的、多次所复的过程;在探埋藏条件下,断层一般是封闭的。自然界中至少存在着两种引起地层压力快速上升并导致深部断层开启的机制：一是地震触发高压致裂;二是深部流体注入引最的连锁压裂。  相似文献   

Rubber Seed Oil as a Novel Substrate for Polyhydroxyalkanoates Accumulation in Bacillus cereus     

《洁净——土壤、空气、水》2017,45(10)

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Experimental characterization,design and modelling of the RBRL seismic‐isolation system for lightweight structures          下载免费PDF全文

Marco Donà  Alan Hugh Muhr  Giovanni Tecchio  Francesca da Porto 《地震工程与结构动力学》2017,46(5):831-853

The Rolling‐Ball Rubber‐Layer (RBRL) system was developed to enable seismic isolation of lightweight structures, such as special equipment or works of art, and is very versatile, a great range of equivalent natural frequencies and coefficients of damping being achievable through choice of the system parameters. The necessity to have a simple and effective design procedure has led to a new parametric experimentation at Tun Abdul Razak Research Centre (TARRC) on the rolling behaviour of the RBRL system and load–deflection behaviour of the recentering springs. The experimental results, together with theories for the rolling resistance of a loaded steel ball on a thin rubber layer and the lateral load–deflection behaviour of cylindrical rubber springs, are used to develop a general design method for the RBRL system, which allows the system to be tailored to the specific application. Sinusoidal test results are presented for the small‐deflection behaviour of the system, influenced by the presence of a viscoelastic depression on the rubber tracks beneath each ball, and an amplitude‐dependent time‐domain model is proposed, based on these results and on the steady‐state behaviour of the system. The model is validated through comparison with previously performed shaking‐table tests. Attention is here restricted to uniaxial behaviour. Copyright © 2016 John Wiley & Sons, Ltd.  相似文献   

Mechanical behavior of lead rubber bearings under and after nonproportional plane loading     

Shiang-Jung Wang  Wang-Chuen Lin  Yu-Sheng Chiang  Jenn-Shin Hwang 《地震工程与结构动力学》2019,48(13):1508-1531

Lead rubber bearings, which have been extensively applied in many seismic isolation designs for buildings, infrastructures, and facilities worldwide, were tested under unilateral reversal loading as well as nonproportional plane loading including circular, figure-eight, and square orbits in this study. The test results indicate that unlike the unilateral hysteretic behavior, the bilateral one of lead rubber bearings is too complicated to be characterized adequately by a simplified bilinear hysteretic model. It is mainly attributed to the bilateral coupling effect, which can be clearly observed from the abnormal deformation of the mesh pattern drawn on the rubber cover during the tests. In addition, after being subjected to nonproportional plane loading, the tested bearings reveal visible permanent twisting deformation. The profiles of the cut bearings present the fracture of the inside lead plugs. Even so, the further unilateral reversal loading test results prove that the fracture might not affect the whole hysteretic behavior and mechanical properties very much. The applicability, robustness, and generalization of adopting three previously developed analytical models for describing the coupled bilateral hysteretic behavior of lead rubber bearings are further demonstrated by comparing their predictions with the nonproportional plane loading test results. Although the coefficients are identified from unilateral reversal loading tests, the three analytical models can still have an acceptable prediction capability.  相似文献   

真空负压静力试桩方法关键技术试验研究     

史永跃  王奎华  董天文  马显春  黄永威 《岩土力学》2020,41(5):1699-1708

现有的静力试桩方法主要有堆载法、锚桩反力架法和自平衡法3种,且各自都存在明显的不足。为了弥补传统基桩静载试验的不足,设计并加工了一套能在工程实践中应用的真空负压静力试桩的反力装置,并进行了原型桩堆载和真空负压静载试验。在试桩上安设了钢筋应力计、桩底土压力盒和桩底位移杆监测传感器及装置,借鉴了地基真空预压排水预压密封系统的措施,形成了有效的密封反力系统。分析了试桩在加载过程中的荷载-位移（Q-s）曲线、位移-时间（s-lgt）曲线,以及轴力、桩侧摩阻力和桩端摩阻力的分布规律。试验表明,桩侧摩阻力的发挥与抽真空过程密切相关。由于负压平台的刚度、压力传递和密封效果原因,真空负压最大加载量级与理论值存在一定差距,针对上述问题提出了相应的解决方案和改进措施。  相似文献   

铅芯叠层橡胶支座恢复力模型研究   总被引：5，自引：0，他引：5  

王建强  王利娟 《世界地震工程》2005,21(2):151-154

在Wen和Park模型的基础上,对铅芯叠层橡胶支座单向和双向耦合恢复力模型进行了改进,使其可以更为准确的模拟铅芯叠层橡胶支座单向和双向耦合的滞回性能。并由计算分析可以看出,考虑双向耦合作用与未考虑双向耦合作用的恢复力滞回曲线有较大差别,因而支座应采用双向耦合恢复力模型以考虑支座的双向耦合作用对结构地震反应的影响。  相似文献   

不同气候适宜区的橡胶产胶潜力研究     

刘少军  张京红  李伟光  陈小敏  佟金鹤 《气象研究与应用》2021,42(1):48-52

基于2000-2015年MODISNPP遥感数据,利用橡胶产胶潜力模型得到了中国橡胶主产区年橡胶产胶潜力;利用橡胶树种植气候适宜性区划的研究成果,得到了中国橡胶主产区橡胶气候适宜区分布;在此基础上分析了不同气候适宜区橡胶产胶潜力的差异及不同高程上橡胶产胶能力的差异.结果表明:(1)中国橡胶主产区中,云南橡胶产胶潜力最高...  相似文献   

黏土地基上海洋平台桩靴峰值阻力上限分析          下载免费PDF全文

张其一  李晓武 《海洋工程》2023,41(1):29-38

在自升式平台的预压载过程中，桩靴在层状地基上较易发生“穿刺”现象，很大程度上影响着平台的安全运行。准确地分析桩靴峰值阻力，避免平台桩靴发生“穿刺”是非常重要的。采用极限分析上限定理，合理构建运动许可速度场，从理论上推导了层状地基上桩靴峰值阻力的上限解答。为了进一步验证峰值阻力理论解答的准确性，采用ABAQUS有限元软件构建了“桩靴—弹塑性海床”的三维数值模型，对桩靴贯入海床的过程进行了数值模拟，分析桩靴周围土体的塑性变形演变规律，研究土体的破坏机理。研究结果表明：推导的桩靴峰值阻力上限解答，能够较好地计算层状地基极限承载能力，通过与离心机试验和数值结果对比，计算误差在18%以内；给出的运动许可速度场能够较好地反映桩靴周围土体破坏模式；桩靴阻力达到峰值时，下层软土中的土塞高度约为桩靴直径的0.2倍。  相似文献