Modelling of viscoelastic plume–lithosphere interaction using the adaptive multilevel wavelet collocation method     

Oleg V. Vasilyev  Yuri Yu. Podladchikov  David A. Yuen 《Geophysical Journal International》2001,147(3):579-589

  相似文献   

Research for time-temperature equivalence effect of rock(Ⅱ):Experimental research   总被引：1，自引：1，他引：0  

ZHU Yuan-guang  LIU Quan-sheng 《岩土力学》2011,32(4):961-966

With the creep test data of granite taken from Three Gorges,the existence of time-temperature equivalence effect(TTEE) of granite is investigated.Based on the creep test data at different temperatures,which are 20 ℃,60 ℃,80 ℃,100 ℃,200 ℃,300 ℃,four-component viscoelastic Burgers model is presented to characterize the creep curves.The parameters of elasticity modulus and viscosity coefficient in the constitutive model at different temperatures and their functional dependences on temperature are obtained.Then,according to the basic theory of TTEE presented in research(I),the TTEE of granite is investigated through modifying the compliance curves with vertical shift function and checking the coincidence of the modified curves with horizontal shift functions.It is concluded that:① Burgers model could appropriately characterize the creep property of granite in a short time scale.② Both elastic modulus and viscosity coefficient in the Burgers model decay exponentially with temperature.③ The coincidence of the curves at different temperatures after vertical shift modification and horizontal shift is fine,which indicates the existence of TTEE of granite.④The master curves which reflect the long time scale test data at temperatures 20 ℃,100 ℃,200 ℃ are obtained.  相似文献   

含多裂纹沥青路面的动力响应分析     

龙晓鸿  张澄  张青军  金祥月 《岩土力学》2011,32(Z2):250-255

考虑沥青材料的黏弹性,结合动力学和断裂力学理论,通过有限元数值模拟研究了含多裂纹沥青路面在移动交通荷载作用下的动力特性,考察了裂纹间距变化对动态应力强度因子以及裂纹尖端应力的影响。研究结果表明,在移动交通荷载作用下基层底面裂纹处于Ⅰ、Ⅱ型动态应力强度因子交替控制下;裂纹间距增大,对基底裂纹应力强度因子的影响逐渐减小;表面裂纹尖端在移动荷载距其较近时受压应力,且随裂纹间距增大,最大压应力先微弱减小后逐渐增大;在移动荷载经过表面裂缝时,裂缝尖端经历了方向相反的剪切作用,随着裂纹间距的增大,最大剪应力呈现先减小后增大的趋势。同时对加铺土工布这一阻裂措施利用数值模拟进行了验证。  相似文献   

块系岩体间黏弹性性质对摆型波传播的影响     

王凯兴  潘一山  曾祥华  肖永惠  李忠华  贾宝新 《岩土力学》2013,34(Z2):174-179

基于深部非连续自应力等级块系岩体构造理论,研究冲击载荷在块系岩体中以摆型波形式传播时岩块间黏弹性性质对摆型波传播的影响。当岩块间具有五种不同黏弹性性质时,通过对块系岩体的始端和末端区域中间岩块加速度响应计算及各岩块加速度正负摆幅幅值分析可知：岩块间黏性变化时,对岩块加速度衰减周期没有影响,但黏性增大时各岩块正负摆幅下降幅度比黏性周期增大时大;岩块间弹性变化时岩块加速度衰减周期均发生变化,但弹性减小时正负摆幅值向平衡位置平移,弹性周期减小时块系岩体的前半部分岩块正负摆幅曲线均出现波动且负摆波动较大,岩块间弹性梯级增大时,岩块加速度迅速衰减,同时各岩块加速度的正负摆幅曲线在初始端区域出现波动。  相似文献   

青藏高原的隆升缩短及其粘弹性形变分析   总被引：2，自引：0，他引：2  

武红岭  王薇  王连捷  张利容  崔军文 《地质力学学报》1996,2(1):17-24

本文依据新生代以来喜马拉雅和青藏高原发生的强烈的构造形变特征,用二维粘弹性有限元数值方法模拟估算了在印度板块向北推挤欧亚大陆的动力条件下,高原各构造单元的形变速率以及由此推算出40Ma以来青藏高原的隆升量和缩短量。反演了各地体岩石力学参数,特别是有效粘性系数η的数量级。认识到物性参数对构造应力场和形变速率的极重要的影响作用。阐明了除了动力机制和边界条件外,岩石圈各圈层材料力学性质的不均一是造成位移场、应力场和形变速率的差异,从而引起各种复杂地质构造现象的基本因素之一。   相似文献   

大型地下储油洞粘弹性稳定性分析   总被引：4，自引：0，他引：4  

王芝银  李云鹏  郭书太  许杰 《岩土力学》2005,26(11):1705-1710

在大型地下岩洞中储油是世界各国石油战略储备的重要方式之一。随着我国石油进口量的不断增加,建造大型地下储油洞库无疑是一种综合经济效益良好的方案。针对大型地下水封储油岩洞库的工程特点,利用数值模拟方法对储库洞群中各洞室的开挖施工顺序进行了仿真模拟计算。通过对3种可能的施工方案所引起的地表变形、洞周关键位置的变形以及应力场和位移场的分布规律对比分析,比选出了洞群中各洞室较优的开挖先后顺序。对筛选出的较优方案进行了施工过程与粘弹性稳定性分析模拟,给出了考虑岩体流变特性时油库的变形规律特点,并对大型地下油库的强度及长期稳定性进行了分析评价,所得结论对地下储油库的开挖施工有一定的参考价值。  相似文献   

Numerical simulation of seismic wave in elastic and viscoelastic TTI media*          下载免费PDF全文

Xuelong Li  Zhi Zhang  Qinqin Ren  Haibo Liu  Fan Xue 《地震科学（英文版）》2020,33(3):116-129

Based on the two-dimensional (2D) three-component first-order velocity-stress equation, the high order staggered mesh finite difference numerical simulation method was used to simulate the elastic and viscoelastic tilted transversely isotropic (TTI) media. The perfect matched layer (PML) absorption boundary condition was selected to eliminate the boundary effect. The results show that: ① Under the condition of fixed elastic parameters of elastic TTI medium, when the polarization angle and azimuth are 60° and 45° respectively, the degree of shear wave splitting is significantly greater than the angle of 0°; ② The influence of viscoelasticity on TTI medium is mainly reflected in the amplitude. If the quality factor decreases, the attenuation of the seismic wave amplitude increases, causing the waveform to become wider and distorted. If the quality factor increases, the viscoelastic medium becomes closer to elastic medium; ③ For TTI medium with different polarization angle and azimuth angle in the upper and lower layers, the shear wave can multiple splits at the interface of medium. The symmetry of seismograms is affected by the polarization angle and azimuth angle of TTI medium; ④ Viscoelasticity has a great influence on reflected wave, transmitted wave and converted wave in the low-velocity model. When the viscoelasticity is strong, the weaker waves may not be shown.  相似文献   

Linear viscoelastic behavior of asphalt mixes from dynamic frequency response functions     

Jean-Claude Carret  Herve Di Benedetto  Cedric Sauzeat 《国际地质力学数值与分析法杂志》2020,44(7):1019-1031

In the small strain domain, asphalt mixes (AM) have a linear viscoelastic (LVE) behavior that is strongly dependent on frequency and temperature. The maximum ratio of modulus values can be up to 1000, and traditional elastic analyses are not pertinent. The possibility to characterize AM from frequency response functions (FRFs) was studied. A new optimization process using the finite element method (FEM) has been developed to back-calculate the LVE properties of AM from FRFs. The numerical optimization process was applied to a reference material with averaged LVE properties determined from tension-compression tests performed on a wide variety of AM types. The LVE properties were modeled considering the 3-Dim version of the model 2S2P1D (2 Springs, 2 Parabolic elements, and 1 Dashpot). Reference FRFs for the considered reference material were obtained from FEM simulations. Three different configurations that may be of interest for practical tests were studied at five different temperatures. The proposed numerical optimization method consists in performing separate optimizations at each temperature to obtain the LVE properties for the considered temperature. Then values obtained at each temperature are considered to optimize 2S2P1D and Williams Landel Ferry (WLF) Equation constants to simulate the global LVE behavior of the material. The accuracy of the process was assessed regarding both the calculated FRFs and the complex modulus evaluation. Results indicate that the proposed optimization process converges almost perfectly towards the reference FRFs. The simulated complex modulus values are also in very good agreement with the values of the reference material.  相似文献   

基于等效黏弹性的变阶分数阶岩石损伤蠕变模型     

李德建  刘校麟  韩超 《岩土力学》2020,41(12):3831-3839

基于分数阶Zener模型与时变黏性Zener模型之间的等效黏弹性，突出弛豫时间在岩石流变黏弹性演变过程中的重要性。当弛豫时间趋近于无穷大，蠕变过程中的黏性演变等同于松弛过程中的黏性演变，并且建立了与弛豫时间相关的损伤因子，解释了损伤因子在岩石流变变形过程的物理意义。利用弛豫时间建立分数阶变阶函数，依此构造变阶分数阶损伤蠕变模型，并且将模型推广到三向应力状态，给出三向应力状态下变阶分数阶损伤蠕变模型。最后基于砂岩的三轴蠕变试验数据，验证了三轴状态下变阶分数阶损伤蠕变模型的可应用性和合理性，试验数据与模型拟合曲线吻合度较高，可以较好地描述蠕变全过程力学行为。模型拟合参数的有效性得到分析和验证，增加了模型在其他复杂应力环境下的可应用性。  相似文献   

Compaction-driven fluid flow in viscoelastic rock     

J. A. D. Connolly  Yu. Yu. Podladchikov 《Geodinamica Acta》2013,26(2-3):55-84

Abstract

Compaction driven fluid flow is inherently unstable such that an obstruction to upward fluid flow (i.e. a shock) may induce fluid-filled waves of porosity, propagated by dilational deformation due to an effective pressure gradient within the wave. Viscous porosity waves have attracted attention as a mechanism for melt transport, but are also a mechanism for both the transport and trapping of fluids released by diagenetic and metamorphic reactions. We introduce a mathematical formulation applicable to compaction driven flow for the entire range of rheological behaviors realized in the lithosphere. We then examine three first-order factors that influence the character of fluid flow: (1) thermally activated creep, (2) dependence of bulk viscosity on porosity, and (3) fluid flow in the limit of zero initial connected porosity. For normal geothermal gradients, thermally activated creep stabilizes horizontal waves, a geometry that was thought to be unstable on the basis of constant viscosity models. Implications of this stabilization are that: (1) the vertical length scale for compaction driven flow is generally constrained by the activation energy for viscous deformation rather than the viscous compaction length, and (2) lateral fluid flow in viscous regimes may occur on greater length scales than anticipated from earlier estimates of compaction length scales. In viscous rock, inverted geothermal gradients stabilize vertically elongated waves or vertical channels. Decreasing temperature toward the earth’s surface can induce an abrupt transition from viscous to elastic deformation-propagated fluid flow. Below the transition, fluid flow is accomplished by short wavelength, large amplitude waves; above the transition flow is by high velocity, low amplitude surges. The resulting transient flow patterns vary strongly in space and time. Solitary porosity waves may nucleate in viscous, viscoplastic, and viscoelastic rheologies. The amplitude of these waves is effectively unlimited for physically realistic models with dependence of bulk viscosity on porosity. In the limit of zero initial connected porosity, arguably the only model relevant for melt extraction, travelling waves are only possible in a viscoelastic matrix. Such waves are truly self-propagating in that the fluid and the wave phase velocities are identical; thus, if no chemical processes occur during propagation, the waves have the capacity to transmit geochemical signatures indefinitely. In addition to solitary waves, we find that periodic solutions to the compaction equations are common though previously unrecognized. The transition between the solutions depends on the pore volume carried by the wave and the Darcyian velocity of the background fluid flux. Periodic solutions are possible for all velocities, whereas solitary solutions require large volumes and low velocities. © Elsevier, Paris  相似文献