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龙门山均衡重力异常及其对青藏高原东缘山脉地壳隆升的约束 总被引：16，自引：0，他引：16
青藏高原东缘处于不均衡状态，自西而东可分为青藏高原弱负均衡重力异常区、龙门山正均衡重力异常区和四川盆地负均衡重力异常区，表明该区的不均衡状态并未导致Airy均衡运动的产生，即龙门山没有均衡下降，而处于不断的隆升状态，显示该地区反均衡运动的构造抬升是导致龙门山隆升的主因。本次采用似三度体重力异常计算方法对该区的正均衡重力异常进行模拟和反演，研究了大尺度地貌分异与均衡重力异常分区之间的相互关系，结果表明，龙门山的下地壳顶面抬升了11．2～12．6km，造成了龙门山的正均衡异常，揭示了构造抬升和剥蚀作用在相似的时间尺度上和空间尺度上控制着龙门山地貌的形成，龙门山的表面隆升是构造隆升和剥蚀作用相叠加的产物。 相似文献
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Liangfu Xie Echuan Yan Jianhu Wang Gongda Lu Guangming Yu 《Environmental Earth Sciences》2018,77(4):156
In this paper, a comprehensive analysis of spatiotemporal characteristics of reverse-dip slope toppling is conducted by taking the Xiaodongcao slope as an example. First, a spatial partitioning analysis of toppling deformation is performed based on the field reconnaissance and interpretation of engineering geological data. Then, the variations of toppling deformation in time domain are analyzed for different areas of the slope with monitored data of surface displacement. Finally, the isochrones of toppling displacement evolution are constructed by using inverse distance weighted interpolation of surface monitoring data at discrete locations. The results presented in the study have shown that: (1) the displacement at the rear of the slope is dominated by vertical deformation, whereas the horizontal deformation is predominant at the slope front which also controls the overall deformation of the bank slope; (2) the overall evolution of slope deformation is dominated by the strip area at the center of the slope. In particular, the overall deformation of the slope lags behind the central region, and the displacement in this strip area could trigger an overall displacement of the bank slope. It is thus inferred that the stripe area serves as the locked segment for the toppling deformation of the slope. 相似文献
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Du Feng Wang Kai Zhang Xiang Xin Chengpeng Shu Longyong Wang Gongda 《Natural Resources Research》2020,29(4):2481-2493
Natural Resources Research - Coal–gas outburst is a complex dynamic phenomenon in underground coal mines that has occurred frequently over the past 150 years. This phenomenon has... 相似文献
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A comprehensive literature review has been carried out on existing models that characterize soil response under the impact of blast shock waves. Various models in the literature are reviewed and discussed in terms of their equations of state that account for the effect of high pressure, failure models that control the yield behaviour, and strength models that represent the effect of high strain-rates, along with a comparison of their advantages and limitations. Then, the application of different soil models to blast-induced liquefaction is elucidated and compared. Consequently, this review provides a comprehensive understanding of the fundamental and unique aspects of modelling soil response subjected to such transient impulsive loading on the grounds of increasing global interest in blast response of soils. 相似文献
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Tailings backfill, which is a subsurface fill mass, has been extensively utilized worldwide in underground mines to fill mined-out cavities for the purposes of ground control and tailings disposal. Just after placement, very early-age backfill which commonly contains a large volume of water exhibits little or no interparticle bonding, and is subjected to the risk of liquefaction induced by routine mine blasting. In this study, a modified total-stress viscoplastic cap model is developed to investigate the blast-induced liquefaction susceptibility of very early-age fill mass under various practical backfilling and field conditions. The developed model well represents the strain-rate and fluid-compressibility dependence of nonlinear material behavior under such dynamic conditions, and also captures the development of excess pore pressure due to irrecoverable volume changes. The model is validated against a series of blast and impact tests on saturated natural soils (sand and silt) and tailings fill masses, and a good agreement is found between the experimental and simulated results. Subsequently, the model is applied to investigate the effects of drainage conditions, distance from detonation, stope size, location of retaining structure, and blast sequence on the liquefaction susceptibility of early-age fill mass after mine blasting. The results obtained from the study will provide practical insight into the blast liquefaction potential of backfill mass in field conditions. 相似文献
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Chengpeng Xin Kai Wang Feng Du Xiang Zhang Gongda Wang Yilei Liu 《Arabian Journal of Geosciences》2018,11(23):747
It is of great significance for the analysis and prediction of coal-gas outburst disasters to understand the mechanical properties and permeability evolution of coal and rock under conditions of stope stress evolution. In this study, mechanical tests were conducted on gas-bearing coal under four stress paths, including conventional triaxial compression (CTC), phased variable speed triaxial compression (PVSTC), unloading confining pressure (UCP), and phased variable speed unloading confining pressure (PVSUCP), simultaneously measuring the permeability in mechanical tests. The mechanical properties and permeability evolutions in gas-bearing coal under four different stress paths were compared. The obtained results show that the deviatoric stress-strain curves of gas-bearing coal under four stress paths could be divided into five stages: compaction, linear elasticity, plastic deformation, stress drop, and residual stress stage. The permeability-strain curves under four stress paths could also be divided into five stages: fast drop, slow decrease, slow increase, sharp increase, and slowed growth. Compared to the CTC conditions, the peak strain and strength of coal under PVSTC conditions increased. Furthermore, the stress drop and energy release under PVSTC were more intense at the moment of instability failure. Compared to both loading paths, the coal was damaged more rapidly under unloading paths and the damage was stronger. Additionally, among both unloading paths, the time required for the failure of coal under PVSUCP was shorter than that under UCP, while the damage under PVSUCP was stronger. The strength characteristics of the gas-bearing coal under PVSTC and PVSUCP still met the Mohr–Coulomb criterion. This preliminary study has guiding significance for the understanding of the co-occurrence mechanisms of coal-gas outburst disasters. 相似文献
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充分认识岩石的地质本质性是准确描述其物理力学特性的桥梁。岩石的地质本质性涵盖了岩石的物质性、结构性和赋存状态3个方面的内容。在综合考虑岩石上述3方面特征及其与单轴试验联系的基础上,以矿物组成、密度、纵波波速和含水状态为基本指标,采用回归和BP神经网络的方法对碳酸盐岩单轴抗压强度进行预测,并采用灰色关联分析法验证本研究所选用的预测基本指标的合理性。实例应用表明：本次采用的回归方法对该类岩石强度预测的最大误差为15.3%,BP神经网络方法预测的最大误差为8.5%。预测误差出现的原因为碳酸盐岩物质组成复杂,所选预测基本指标是实际情况的简化,同时泥灰质岩石所具有的膨胀性也导致实测和预测结果具有一定的差异。 相似文献
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A coupled chemo‐viscoplastic cap model for simulating the behavior of hydrating cemented tailings backfill under blast loading 
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下载免费PDF全文 Although the use of blasting has become a routine in contemporary mine operations, there is a lack of knowledge on the response of cement tailings backfills subjected to sudden dynamic loading. To rationally describe such a phenomenon, a new coupled chemo‐viscoplastic cap model is proposed in the present study to describe the behavior of hydrating cemented tailings backfill under blast loading. A modified Perzyna type of visco‐plasticity model is adopted to represent the rate‐dependent behavior of the cemented tailings backfill under blast loading. A modified smooth surface cap model is consequently developed to characterize the yield of the material, which also facilitates hysteresis and full compaction as well as dilation control. Then, the viscoplastic formulation is further augmented with a variable bulk modulus derived from a Mie–Gruneisen equation of state, in order to capture the nonlinear hydrostatic response of cemented backfills subjected to high pressure. Subsequently, the material properties required in the viscoplastic cap model are coupled with a chemical model, which captures and quantifies the degree of cement hydration. Thus, the behavior of hydrating cemented backfills under the impact of blast loading can be evaluated under any curing time of interest. The validation results of the developed model show a good agreement between the experimental and the predicted results. The authors believe that the proposed model will contribute to a better understanding of the performance of cemented backfills under mine blasting and contribute to evaluating and managing the risk of failure of backfill structures under such a dynamic condition. Copyright © 2015 John Wiley & Sons, Ltd. 相似文献