南芬露天铁矿下盘采动时边坡稳定性数值模拟

通过分析南芬露天铁矿下盘边坡的区域地质资料,确定出降雨和爆破震动为影响边坡稳定性的主要因素。根据前期研究成果,对5#坡体剖面建立数值模拟计算模型,同时导入SLOPE/W模块,分析爆破和降雨耦合作用对扩帮前后边坡稳定性的影响。研究结果表明：岩体扩帮采动前后孔隙水压力变化不大,但是在近似梯形岩体开挖之后,一部分自重应力被消除,对边坡的地应力产生了显著影响。扩帮采动后的边坡在耦合作用下整体安全性变差,但依然保持稳定。286~454 m段属危险性边坡,454~574 m段边坡保持稳定。     

基于低影响开发理念的生态雨洪规划研究 ——以株洲市云峰湖社区为例

在城乡发展过程中,由于长期以来 缺乏生态雨洪系统规划,导致城市在应对雨 洪问题时往往处于被动状态,对于可以有效 利用的雨洪资源不但没有得到科学的利用, 反而对居民的生产生活和城乡的健康发展 造成巨大的影响。通过对城市边缘区的株洲 市云峰湖社区的雨洪现状问题进行深入分 析,结合低影响开发理念,从社区排水道的 生态设计、雨洪滞留区设计及生态水管理这 三个方面提出具体的规划设计措施,以期为 提高社区雨洪安全和缓解城区雨洪压力有 所助益。     

Transport and Distribution of Particulate Matter Phosphorus Fractions in Rainfall-Runoff from Roadway Source Areas

During runoff transport, phosphorus (P) partitions between dissolved and particulate matter (PM) phases. PM-based P distributes across the particle-size distribution (PSD). This study investigates the transport and distribution for P and PM in runoff from a fully paved highway watershed in Baton Rouge, La. Eight events with discrete manual runoff sampling are studied. PSDs are modeled with a cumulative gamma distribution and PM-based P distributions are modeled with a Freundlich-type power law. P and PM fractions examined are dissolved, suspended, settleable, and sediment. Measured mass transport of these fractions is modeled based on flow-limited (zero-order) or mass-limited (first-order) delivery. Results demonstrate that transport of each fraction can be represented by these limiting categories, but fractions illustrate differing elution rates during the same event. Event-based signatures for PM or P are controlled by the fraction that dominates the transported mass. Even for small source area catchments such as roadways without complex flow patterns, where first-order transport should dominate, transport of P and PM fractions is not consistently first-order; exceptions are mainly dissolved and suspended fractions. A water quality volume (WQV) for 25 mm of runoff resulted in 100% capture for all fractions of seven events and significant bypass for all fractions of a single event with a 1-year return frequency. By contrast, a WQV of 5 mm of runoff resulted in significant bypass for most fractions for seven events and 100% capture for the single event of the lowest runoff volume.     

长历时降雨对高陡边坡排土场渗流影响分析及稳定性研究

高台阶排土工艺使得排土场呈现高陡边坡趋势,降雨则是诱发高陡边坡滑动的一个重要因素。以某多雨地区高陡边坡排土场为例,开展了长历时降雨条件下渗流演化规律及稳定性影响分析。研究表明：排土场堆积高度越大,降雨对内部孔隙水压力分布的影响越小;排土场稳定性在不同降雨时期受深层和浅层2种不同的滑动方式控制;降雨引起抗滑稳定系数的降低速率大于停雨后安全系数的升高速率。     

利用雨量雷达构建面雨量自动监测系统

雨量雷达是专门适用于气象目标中降雨量定量测量的雷达设备,高分辨区域面雨量自动监测系统则是应用雨量雷达进行区域内雨量监测,监测系统通过雨滴谱仪与模型算法解决衰减订正和雨量数据计算准确度问题,可以方便地获得区域内的降雨分布情况和有效的降雨量,与常规单点雨量定量测量相比,在较大区域内测量雨量,整体上精度高,成本低。经过大理监测区域的验证,面雨量自动监测系统具备较高的测量精确度,具有较好应用前景。     

Experimental study on the anti-clogging ability of siphon drainage and engineering application

The safety of the slope retaining wall along the expressway is often threatened by groundwater, and the clogged drainage holes, which seriously affects the safety and stability of the retaining wall. To solve the clogging issue of the drainage hole, in this research, model tests and theoretical analysis were carried out to demonstrate the existing of clogging problem of the siphon drainage, the results showed that the soil particle (d < 1 mm) can be carried out by siphon drainage with 4 mm pipe diameter, the anti-clogging ability of siphon drainage with 4 mm pipe diameter was clarified. And the siphon drainage was applied to the retaining wall along the Longli Expressway. The monitoring data of the groundwater level showed that the groundwater level after the arrangement of siphon drainage was significantly decreased. There was no indication of clogging for the siphon drainage within the four-month of operation. It proves the implementation of siphon drainage method can effectively reduce the groundwater level behind the retaining wall in the rich water area, and it is a long-term method to treat the leakage hazard of the retaining wall.     

降雨对排土场边坡渗流及稳定性的影响

以降雨时期排土场的稳定性为研究对象,结合唐山某排土场堆积特征和地区气象条件,基于Geo-studio软件中SLOPE/W、SEEP/W等多个模块的不同算法,估算理论派生土体的土水特征曲线和渗透系数函数,计算了矿山排土场边坡在天然状态时的最小安全稳定性系数,分析了不同降雨状态下排土场边坡渗流特征。研究结果表明：一定的降雨强度下,随着降雨时间的增长,排土场坡体内的浸水面深度逐渐增加,孔隙水压力增大,安全稳定性系数在逐渐降低,边坡将向不稳定状态演变;降雨强度增大,会使边坡稳定性系数降低的速度增加,随着降雨强度和降雨时间的持续增加,边坡终将向不稳定状态演变。     

Measurements of 11 GHz attenuation using the intelsat V beacon in Indonesia

A campaign of measurements in Indonesia has been carried out according to a co-operation agreement concluded between the Indonesian and French Administrations with the aim of estimating rain attenuation on slant paths. The experiment was planned using two earth-stations, at Cibinong and Padang, both receiving a K_u-band beacon from an INTELSAT V satellite, coupled with rain-rate measurements at a number of sites. Rain-rate statistics are given for several locations in the Indonesian Archipelago. Cumulative distributions of attenuation and simultaneous rain rate, obtained at the earth-stations, are presented. The analysis of the results has led to the proposal of an adaptation of the CCIR attenuation prediction method for low latitudes.     

Probabilistic 8-day rainfall estimates for the Sanaga basin,Cameroon

A method has been developed to produce 8-day forecasts or estimates of future rainfall over the 132 000 km² Sanaga basin in Cameroon. The estimates provide the input to a real-time flow management system which determines optimum reservoir releases to achieve expected power demands, and thereby tries to make the most effective possible use of the water resources of the basin. Attempting to forecast deterministically for up to 8 days ahead was not thought to be practicable, and a probabilistic approach was taken instead. This means that each forecast is associated with a reliability or probability of exceedance. In the initial technique, based on an analysis of historic data, the forecasts are determined by the date only. An additional forecasting method was also developed which includes the current position of the FIT (the local name for the ITCZ) as a causative factor but still maintains the forecasts on a probabilistic basis. This uses the variation of the FIT from its usual position for the time of year to determine whether the forecast rainfall should be greater or less than the standard forecast for that date, and so includes some ability to take account of the variability of rainfall. The forecasting system is believed to be a novel approach to a problem which has not been tackled before. While far from providing a complete solution to the problem of rainfall forecasting in real-time basin management, it does illustrate an approach that can be attempted in the absence of reliable deterministic techniques.     

代表单元尺度概念及其在洋河流域控制雨量站布设中的应用

本文首次提出代表单元尺度概念及其协同学意义，在划分子单元规模时，大于代表单元尺度的子区域之间相互独立，而小于该尺度的子区域之间彼此空间结构相关，在小于ＲＥＬ的尺度上研究问题时，必须考虑区域内各量的空间结构，不能用简单的平均方法以点代面，对大于ＲＥＬ的尺度上研究时，由于子区域间相互独立，可以考虑用算术或权重平均以点及观，可应用半方差理论确定代表单元尺度，最后应用代表单元尺度概念分析了河北省洋河流域遥