Size distribution of free particles in soils: a geometric modelling approach

Acta Geotechnica - Suffusion is a typical form of internal erosion for gravel soils in which fine particles are detached by seepage and transport by water through pores. The prediction of erodible...     

GM3磁通门磁力仪稳定性分析

通过2002～2003年的GM3磁通门磁力仪的资料,对该仪器的各项指标进行稳定性分析,考核运行状态是否正常,以证明是否替代模拟观测仪器。     

城乡共享背景下的区域绿道选线模型构建探索

区域绿道是集生态保护、经济发展和民生改善等多种功能于一体的复合型廊道。区域绿道的科学选线是利用绿道集聚城乡资源、转化生态价值的基础。本文以湘潭市莲城绿道为案例,基于国内外绿道选线相关研究,充分利用传统规划业务数据和新型地理信息数据,建立多源数据融合的空间适宜性评价模型,并通过路网布局流程模型模拟出不同情景逻辑下的选线方案,通过方案叠加对比,综合确定绿道布局。     

Establishing a monitoring network for an impoundment-induced landslide in Three Gorges Reservoir Area, China

A methodology for monitoring system of an impoundment-induced landslide in Three Gorges Reservoir Area, China is introduced. Currently, based on landslide geological classification, the monitoring regions and methods which include types of monitoring instruments, placement and calibration precision of instruments, and appropriate periods for instrumental placement is confirmed. To optimize the monitoring system, sensitivity analysis of displacements and the water table in landslides affected by reservoir surface fluctuation is completed to determine the layout of the monitoring cross sections and the monitoring points. As a case study, the behavior of displacements and the potential fluctuation of the water table in the Shiliushubao landslide, produced by the gradual water impoundment at Three Gorges Reservoir, has been simulated using 3D finite element method analysis. The sensitivity analysis of Shiliushubao landslide is investigated by the fuzzy set evaluation method. As a result, the monitoring network of Shiliushubao landslide is established.     

Physical modelling and numerical analysis of slope instability subjected to reservoir impoundment of the Three Gorges

Increasing attention is being given to investigations of failure mechanisms of unstable slopes influenced by water fluctuation during impoundment, such as in the case of reservoir landslides surrounding the Three Gorges, China. In this paper, two typical soil slopes with thin and thick rear edges are considered in a systematic investigation of the large-scale landslides triggered by reservoir impoundment. Physical model test, centrifugal modelling and numerical analysis are presented; these show the deformation evolution process and are aimed at obtaining the physical and mechanical laws that govern deformation and failure of such typical slopes during increasing water levels in a reservoir. The results indicate that deformation of the soil slopes triggered by impoundment can be divided into three stages: the rapid deformation stage, the slow development stage and the convergence creep stage. Moreover, deformation increases rapidly in the initial water level increase, and deformation growth slows with continued increase in water levels. Although the failure modes of the two typical slopes were not identical, the deformation in both started when soil softening occurred, suggesting that the initial phase of water level rise is likely the most dangerous phase with respect to soil slope stability. The results are likely to provide a foundation for further disaster mechanism studies, as well as disaster prevention and reinforcement design of reservoir soil slopes.     

村庄规划统筹集体经营性建设用地实证分析——以安仁沿滩村为例

本文结合村庄规划实践,就村庄规划统筹集体经营性建设用地进行实证分析。从产业发展用地需求和可供给土地潜力分析两个方面双向验证,进而提出集体经营性建设用地规划选址与规划条件。研究表明：村庄规划应从自然资源禀赋出发,找准目标定位,明晰产业发展规划,摸清用地需求;同时应防范风险,坚持底线思维和农民主导地位,进行适宜性判断,厘清可供给土地;进而统筹安排集体经营性建设用地。也提出了从乡镇层面统筹谋划集体经营性建设用地,服务乡村振兴,为一二三产融合发展提供土地要素支撑的建议。     

“双评价”在国土空间规划中支撑方式研究——以凤凰县为例

本文结合\"双评价\"工作实践,面向国土空间规划编制需求,以凤凰县\"双评价\"为例,进行资源环境禀赋现状分析与国土空间格局特征分析,并从指标约束传递为国土空间规划设置空间管控底线,主体功能区识别与三区划定实现功能传导为国土空间用途管制提供依据,风险识别与应对为国土空间规划决策提供依据三个方面,探索\"双评价\"在国土空间规划中支撑方式。     

一种Pb-PbCl2不极化电极试验研究

在分析不极化电极基本实现原理的基础上,研究和讨论影响地电场测量电极工作稳定性的主要技术因素,采用Pb-PbCl2技术方案和可螺旋拆解的分体式结构,完成一种不极化电极的研究和试验。结果表明：①该电极的主要技术性能不低于目前国内外在该领域的指标要求;②在性能试验期间,极化电位的一致性和稳定性均较高;③应用研究过程中,较好记录了地电场日变化和地电暴等背景变化。     

水布垭马崖高边坡岩体地下开挖三维数值模拟研究

清江水布垭水电站是清江上游拟建的一个特大型水电工程,马崖高边坡位于水布垭峡谷出口右侧,总体地质结构具上硬下软特征,电站导流洞及尾水洞将从马崖高陡边坡坡脚穿出,地下开挖主要在软岩层中。应用FINAL及ROCKY程序对水布垭马崖高陡边坡岩体地下开挖进行数值模拟,研究了边坡岩体内进行地下洞室开挖后边坡力学状态的改变及洞室岩体（含岩柱）的稳定性,基于削坡是水布垭马崖高陡边坡的重要整治措施之一,研究中进行了各种分步开挖工况下的削坡有效性定量研究,重要工况还同时进行了VI度地震作用下的动力作用分析。