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91.
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。 相似文献
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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. 相似文献
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《Soils and Foundations》2022,62(6):101221
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. 相似文献
97.
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。 相似文献
98.
M. Juy R. Maurel M. Rooryck I. A. Nugroho T. Hariman 《International Journal of Satellite Communications and Networking》1990,8(3):251-256
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 Ku-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. 相似文献
99.
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. 相似文献
100.
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 总被引:2,自引:0,他引:2
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 相似文献