省级GRAPES模式预报系统的构建     

李周  孔海江  宋伟  谷秀杰  乔春贵 《河南气象》2007,(4)

利用9210卫星广播的T213资料作为初始场,在联想深腾1800机群系统上构建了省级GRAPES中尺度数值预报系统,实现了GRAPES-MESO V2.5的高效运行,一方面可提供日常的业务预报产品,另一方面也可为广大预报员提供一个诊断模拟的平台。  相似文献   

青藏高原东南缘盐源—宁蒗盆地的三维大地电磁成像及对油气资源勘探的启示     

王桥  杨剑  夏时斌  廖国忠  张伟  李华  李德伟 《地质论评》2023,69(Z1):319-319

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基于C-V-T模型的盾构穿越既有桥梁施工风险评估     

阮永芬  张虔  乔文件  裴利华  闫明  郭宇航 《岩土力学》2023,(2):552-562

由于城市轨道交通建设逐年增多,新建隧道与既有桥梁间冲突愈发明显。针对盾构隧道穿越既有桥梁施工风险问题,基于系统思想引入C-V-T模型将待评工程风险划为后果严重性（C）、既有桥梁系统脆弱性（V）与新建隧道系统威胁性（T）,构建致灾-承灾-灾后三系统风险评估流程。引入双因素突变理论并建立三级指标体系,得出既有桥梁突变级数,以定量表达脆弱性。采用交互矩阵衡量新建隧道指标间交叉影响,给出指标-系统权法,并利用多维云及正向发生器优化算法,客观表达多定量指标与定性概念间复杂映射关系及转换态势,以提升T值准确性。明确了后果严重性分级标准,给出三系统风险评估结果耦合方法,由此构建盾构穿越既有桥梁施工风险综合评估模型。将该模型应用于昆明地铁5号线穿越怡心桥工程风险评估中,评估结果与工程实际情况吻合,施工监测数据验证了评估模型的合理性、规范性与适用性。该研究成果有效保证了施工期间桥梁安全与正常使用,可为近似工程提供借鉴与参考。  相似文献   

山西太原西山汾河二库的泉域归属及其渗漏量计算   总被引：1，自引：1，他引：0  

郭芳芳  梁永平  王志恒  申豪勇  赵春红 《中国岩溶》2018,37(4):493-500

山西省汾河二库是建于汾河中上游的一座大型水库。由于水库处于晋祠兰村泉域交界地带的碳酸盐岩河段,水库蓄水并淹没了天然条件下出流的悬泉寺泉群,造成库区岩溶水文地质条件发生根本性改变,直接影响到泉域岩溶水的水资源评价、开发管理和以泉水复流为目标的生态修复的措施制定。本文针对汾河二库修建后的以下两个问题开展了讨论。第一,利用最新调查与勘探资料分析二库修建对岩溶水文地质条件的影响,并对二库库区的泉域归属问题进行了划定,认为悬泉寺泉水的出流受控于汾河河谷内向西倾斜的下奥陶统区域相对隔水层的阻水作用,汾河二库蓄水水位提高近40 m,天然条件下挟持于晋祠-兰村泉域间相对独立循环的悬泉寺泉域降落漏斗被“充满”,泉水消失,形成对岩溶地下水渗漏反补给,水库渗漏水量通过中奥陶统主要进入晋祠泉域,汾河二库以寺头-下槐间下奥陶统出露的地段为界,下槐泉以上划归晋祠泉域,下槐泉以下则划归兰村泉域;第二,利用二库上游寨上水文站、下游的上兰村水文站资料和二库蓄水水位系列资料,由均衡法建立了二库蓄水水位与渗漏量之间的非线性方程,并据此预测,当二库水位提高至905.7 m时的渗漏量为2.862 m3·s-1,而对兰村泉域岩溶水及山前西张水源地的补给量有限。   相似文献   

三维成矿预测与预测评价——以东昆仑成矿带红旗沟—深水潭金矿为例     

胡桥  陈建平  田业 《现代地质》2018,32(2):335

红旗沟—深水潭金矿是东昆仑成矿带中典型的构造蚀变岩型金矿,矿体严格受控于破碎蚀变带。通过对东昆仑地区成矿地质背景的梳理以及金矿成矿过程的分析,在构建三维地质模型的基础上提取成矿有利因子,建立找矿预测模型,并计算找矿信息量。在此基础上,从最优分级分析、精度分析和结果分析三方面进行信息量分级评价、预测区分级评价、数据精度评价、找矿预测模型的有效性评价以及找矿靶区的定位精度评价、预测资源量估算和找矿概率评价等研究。研究共圈定4处找矿靶区,并估算全区金资源量约165 t。结果表明红旗沟—深水潭金矿的找矿潜力较大,后期应该重视已知矿体的深部及边部区域的重点勘查。  相似文献   

Role of particle crushing on particle kinematics and shear banding in granular materials     

Gang Ma  Richard A. Regueiro  Wei Zhou  Qiao Wang  Jiaying Liu 《Acta Geotechnica》2018,13(3):601-618

The paper provides an in-depth exploration of the role of particle crushing on particle kinematics and shear banding in sheared granular materials. As a two-dimensional approximation, a crushable granular material may be represented by an assembly of irregularly shaped polygons to include shape diversity of realistic granular materials. Particle assemblies are subjected to biaxial shearing under flexible boundary conditions. With increasing percentage of crushed particles, mesoscale deformation becomes increasingly unstable. Fragmented deformation patterns within the granular assemblies are unable to form stable and distinct shear bands. This is confirmed by the sparsity of large fluctuating velocities in highly crushable assemblies. Without generating distinct shear bands, deformation patterns and failure modes of a highly crushable assembly are similar to those of loose particle assemblies, which are regarded as diffuse deformation. High degrees of spatial association amongst the kinematical quantities confirm the key role that non-affine deformation and particle rotation play in the generation of shear bands. Therefore, particle kinematical quantities can be used to predict the onset and subsequent development of shear zones, which are generally marked by increased particle kinematic activity, such as intense particle rotation and high granular temperature. Our results indicate that shear band thickness increases, and its speed of development slows down, with increasing percentage of crushed particles. As particles crush, spatial force correlation becomes weaker, indicating a more diffuse nature of force transmission across particle contacts.  相似文献   

Comparative study on three-dimensional statistical damage constitutive modified model of rock based on power function and Weibull distribution     

Song Chen  Chunsheng Qiao  Qing Ye  Muhib Ullah Khan 《Environmental Earth Sciences》2018,77(3):108

According to the characteristics of the microscopic unit strength of rock with random distribution, the power function distribution, and the Weibull distribution which is widely used in the past as the distribution function of the strength of the rock. Based on the theory of rock damage and statistical strength theory, two damage constitutive models established under three different confining pressures are modified. Then, the damage constitutive modified model of two kinds of distribution is verified and compared with the existing three axis test data. The results show that: (1) In the stage of elastic deformation of rock, the two theoretical damage constitutive model curves are in high agreement with the three axis test curve; (2) The rock at the plastic stage (hardening and softening), damage constitutive model established by Weibull probability distribution and experimental curve fits better than the damage constitutive model established by power function distribution. Especially in high confining pressure, damage constitutive model based on Weibull distribution can well describe the rock deformation from brittle to ductile transition process and power function is not; (3) In the residual strength in rock, damage variable D of damage constitutive model based on power function distribution appeared more than 1, which is deviation from the actual one and damage constitutive model based on Weibull distribution is not deviating. To summarize, using Weibull distribution statistical probability model to describe the microscopic unit strength of rock is more reasonable.  相似文献   

Modelling the response of vegetation restoration to changes in groundwater level,based on ecologically suitable groundwater depth     

Fawen Li  Yan Wang  Yong Zhao  Jiale Qiao 《Hydrogeology Journal》2018,26(7):2189-2204

Groundwater-level fluctuations at a large scale have a significant effect on the preservation and restoration of vegetation. This study determined suitable groundwater depth within which natural vegetation grows well, and analysed the effect of groundwater regulation on vegetation restoration in Tianjin City, northern China. Normal and lognormal distributions were used to fit the curve of the relation between vegetation and groundwater depth. The groundwater depth range corresponding to the higher frequency of vegetation distribution was regarded as the ‘suitable water depth’ range for vegetation growth. The suitable groundwater depth for shrub growth was 3–5 m and for grass growth 1–3 m. A groundwater flow model predicted the future changes of groundwater depths in the vegetation distribution area under the condition that the current levels of groundwater extraction are maintained. The results showed that there is potential for the extraction of groundwater in shrubland areas, but for grassland areas the water-table elevation showed a downward trend, meaning that water shortages in some areas may be more severe in the future. Finally, based on the current groundwater extraction regime, two regulation schemes were developed: (1) for shrubland, groundwater extraction was reduced by 10% in the ecological water deficit areas, and extraction was increased by 10% in the ecological water surplus and suitable areas, and (2) for grassland, groundwater recharge was increased by the restoration of the wetland areas. In conclusion, the groundwater depths in most of the area would be more suitable for vegetation growth under the regulation schemes.  相似文献   

Review: Characterization,evolution, and environmental issues of karst water systems in Northern China     

Yongping Liang  Xubo Gao  Chunhong Zhao  Chunlei Tang  Haoyong Shen  Zhiheng Wang  Yanxin Wang 《Hydrogeology Journal》2018,26(5):1371-1385

In Northern China, karst systems in widely distributed carbonate rocks are one of the most important water supplies for local inhabitants. Constrained by the specific geological and geomorphological conditions, most karst water in this region is discharged as individual or groups of springs. This paper summarizes the characteristics, chemistry, and environmental quality of these karst systems in Northern China. Five structural models of karst water systems were identified based on the relationships between the karst geological strata and karst groundwater flow fields. These specific structural models may closely relate to the attendant environmental geological issues and consistent risks from pollution. Over the past 40 years, the karst water systems in Northern China have suffered from various environmental problems, including deteriorating water quality, the drying up of springs, a continuous decline in the level of karst water, and so on. Based on the field investigation and previous data, a preliminary summary is provided of the environmental problems related to the development and evolutionary trends of karst water in this region. The results highlight the significant challenges associated with karst water, and it is essential that all segments of society be made aware of the situation in order to demand change. In addition, the study provides a scientific basis for the management, protection, and sustainable utilization of karst water resources.  相似文献   

Review: Approaches to research on CO2/brine two-phase migration in saline aquifers     

Dayong Wang  Bo Dong  Stephen Breen  Minglong Zhao  Juan Qiao  Yu Liu  Yi Zhang  Yongchen Song 《Hydrogeology Journal》2015,23(1):1-18

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