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。     

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。     

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.     

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.     

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。     

新泰蒙阴盆地无坊子组

通过对新泰市汶南镇朝阳村至庄家庄一线北侧一套含煤地层的观察和化石采集,共采到植物化石２０余件,经鉴定有Ｓｐｈｅｎｏｐｈｙｌｕｍｏｂｌｏｎｇｉｆｏｌｉｕｍ（Ｇｅｒｍ．ｅｔＫａｕｌｆ）Ｕｎｇ．,Ｎｅｕ－ｒｏｐｔｅｒｉｓｏｖａｔａＨｕｆｍ．,Ｎ．ｐｌｉｃａｔａＳｔｅｒｎｂ．,Ｎ．ｃｆ．ｐｌｉｃａｔａＳｔｅｒｎｂ．,Ｎ．ｓｐ．,Ｐｅｃｏｐｔｅｒｉｓｃｆ．ｃａｎｄｏｌ－ｌｅａｎａＢｒｏｎｇｎ．,ＣｏｒｄａｉｔｅｓｓｃｈｅｎｋｉＨａｌｅ,ＳａｍａｒｏｐｓｉｓｓｉｎｅｎｓｉｓＨａｌｅ５属８种。该植物组合属我国早期华夏植物群〔１〕,时代为晚石炭世。含该植物组合的地层应为太原组,证明新泰蒙阴盆地无坊子组。     

全方位自然电场观测方法和观测技术研究

自然电场是一种物理意义比较明确, 变化(孕震)机理相对明晰的地球物理场, 在矿产资源勘探、 水文地质勘测等领域有着比较广泛的应用, 在地震监测领域也有了多年的探索和实践. 本文在初步研究全方位自然电场观测方法的基础上, 重点分析和讨论了基于全方位自然电场观测技术, 包括一种Pb-PbCl₂不极化电极、 多测道高精度数据测量、 网络控制与数据通信等组件和模块的基本原理和技术实现方法, 便携式设计和环境温度适应能力的技术实现途径等, 并对天津市静海地震台的自然电场试验观测系统及观测数据进行了简要介绍和分析讨论. 结果表明: ① 全方位自然电场观测方法能够捕捉到各个方向自然电场及其随时间的变化; ② 自然电场观测技术系统能够配合全方位自然电场观测方法, 在360°范围内开展自然电场及其随时间变化的动态变化测量, 具有较高的观测精度、 较强的抗干扰能力和观测环境适应能力; ③ 天津市静海地震台的试验观测系统记录到了可能与周边水系的季节性变化有关的自然电场全方位变化.      

茅台酒用高粱产量品质与气象因子研究

为研究仁怀市茅台酒用高粱栽培基地气象要素对高粱产量和品质影响的关键因子和关键时期.采用空间曲面插值方法,对仁怀及周边气象站气象数据进行空间插值,得到100m×100m的高分辨要素空间分布栅格数据.然后应用种植在海拔370～1301m的127个地段高粱数据与气象资料进行分析.结果表明,温度、日照对产量影响主要在齐穗期后10d～40d;降水影响产量的关键时段在齐穗前50d到齐穗后40d.气象因子对产量的影响都十分显著(＞99％置信度).降水、日照与单宁含量呈现较显著反相关(＞95％置信度),并且都出现在齐穗前20d ～50d左右.但气象因子与蛋白质含量无显著相关.