Permeability of Hydraulic Fills and Barricade Bricks     

Nagaratnam Sivakugan  Kirralee Rankine  Rudd Rankine 《Geotechnical and Geological Engineering》2006,24(3):661-673

Permeability is one of the most important parameters in the design of hydraulic backfilling of mine stopes. A simple and reproducible method was developed for preparing reconstituted hydraulic fill sample in the laboratory, that is representative of the hydraulic fill in the mine stope, replicating the slurry sedimentation process taking place in the mine. Constant head and falling head permeability tests were carried out on the samples, giving consistent results. A brick permeameter was developed to study the flow characteristics of the porous barricade bricks under one-dimensional flow, simulating the flow conditions in the mine. Three different methods were used to determine the permeability of the brick and the results showed very good agreement. This is the first rational attempt to measure the permeability of the porous barricade bricks that are used to close the horizontal access drives in the mines, thus retaining the hydraulic fill. The measurements show that the permeability of the barricade brick is about two to three orders of magnitude greater than that of the hydraulic fill.  相似文献   

不同压实度下红层泥岩路堤沉降研究     

刘俊新  谢强  白明志  邱恩喜 《工程地质学报》2006,14(5):683-688

压实系数是控制路堤填筑的关键性指标。本文通过分析不同压实系数下的强度特点以及通过离心试验和有限元对不同压实系数路堤沉降的模拟,得到粘聚力c值和摩擦角与不同压实系数的关系以及不同压实系数下路堤沉降的特点,为路堤填筑提供了重要的依据。  相似文献   

Dynamics and interaction of organic carbon, turbidity and bacteria in a karst aquifer system   总被引：9，自引：8，他引：9  

Michiel Pronk  Nico Goldscheider  Jakob Zopfi 《Hydrogeology Journal》2006,14(4):473-484

The dynamics of organic carbon (OC), turbidity, faecal indicator bacteria and physicochemical parameters was studied in a karst system near Yverdon, Switzerland. Online measurements and sampling were done at a swallow hole draining an agricultural surface (the input), and two groups of springs (the outputs) that often show bacterial contamination. A fluorescent tracer that was injected into the swallow hole during low-flow conditions first arrived at the springs 10–12 days after injection; the total recovery rate was 29%. Previous tracer tests during high-flow conditions gave shorter travel times. After a major rainfall event, a primary turbidity peak was observed at the springs. It coincides with the rising limb of the hydrograph, indicating remobilisation of autochthonous particles from the aquifer. A secondary turbidity peak occurs several days later, suggesting the arrival of allochthonous particles from the swallow hole. Wider peaks of OC and bacteria were observed simultaneously. Applying methods from molecular microbiology (PCR-DGGE) allowed characterisation of the bacterial communities at the swallow hole and the springs. The results demonstrate that the swallow hole is an important source of groundwater contamination, while its contribution to aquifer recharge is insignificant. OC appears to be a better indicator for bacterial contamination than turbidity.  相似文献   

条带开采煤柱稳定性的试验模拟与数值分析——以山东省济宁市太平煤矿为例   总被引：1，自引：0，他引：1  

杨伟峰夏筱红  黄治灿刘汪威 魏永军 《中国煤田地质》2005,17(2):29-31,55

以山东省济宁市太平煤矿为例，采用煤柱模拟试验和数值分析手段，对薄基岩条带开采时所留设煤柱的应力应变状态、煤柱强度结构及煤柱长期稳定性进行了深入的分析与研究，揭示了煤柱稳定性及煤柱应力分布与条采尺寸、采出率、覆岩特征的相互关系，进行了条带煤柱的稳定性评价，为工程实践提供了理论依据。  相似文献   

韧性剪切变形对岩石地球化学行为的制约——以北阿尔金巴什考供韧性剪切带为例   总被引：6，自引：0，他引：6  

戚学祥李海兵  吴才来陈松永 《地质通报》2005,24(3):252-257

韧性剪切变形对岩石地球化学行为的制约一直是地质学家们探讨的课题。本文以构成北阿尔金红柳沟——拉配泉俯冲碰撞杂岩带与北阿尔金地块边界的巴什考供斜向逆冲型韧性剪切带为例，通过对韧性剪切带内花岗岩变形前后不同变形强度构造岩的地球化学组成进行对比，确定等比线斜率，探讨韧性变形对岩石体积和成分变异的影响。计算结果表明，在糜棱岩化过程中，糜棱岩化花岗岩体积亏损21％，花岗质糜棱岩体积亏损31％。质量平衡计算结果和等比线图表明，韧；陛剪切作用导致SiO2，流失量最大，A12O3、K2O及Ba、Rb、Sr等都有不同程度的丢失，显示出较强的活动性，MnO、P2O5、Sc位于等比线上或附近，表现出相对的稳定性。岩石中活动组分的变异是流体渗滤作用引起的，不活动组分的变异是体．积亏损造成的。  相似文献   

粉煤灰浸出特性试验研究     

郭建新 《地下水》2005,27(5):405-407

利用浸出试验方法,对火电厂粉煤灰进行浸出特性的测定,对其有害特性进行鉴别并分析其浸出规律,从而为地下水受粉煤灰排水影响后的水质预测、堆灰场选址、环境影响评价提供依据.  相似文献   

地下导线随盾构推进逐段接测中的可靠性检验     

高俊强  潘庆林 《现代测绘》2005,28(1):17-19

盾构法施工的要点是需要在井下布设高精度的控制支导线，当我们根据盾构推进进度对导线接测时，由于观测条件、观测方法、观测仪器基本相同，但观测、的成果往往会存在一定的差异，有时我们无法直接判断成果的正确与否，此时，采用测量平差中的统计检验的方法来分析这些观测数据，可以取得比较满意的结果。  相似文献   

用940 nm通道遥感水汽总量的可行性试验   总被引：7，自引：2，他引：7       下载免费PDF全文

黄意玢  董超华 《应用气象学报》2002,13(2):184-192

在940 nm水汽弱吸收带和其附近窗区选取若干探测通道, 采取不同通道组合, 模拟计算通道反射率比值, 并建立了该比值与水汽含量之间的统计关系。用探空观测独立样本检验水汽含量模拟计算结果, 相对误差小于6%。  相似文献   

DGSC—203型液动射流冲击器在地热井的试验   总被引：4，自引：0，他引：4  

菅志军  桑路等 《地质与勘探》2002,38(5):92-93

介绍了新研制的DGSC－203石油钻井液动射液冲击器的性能参数及结构设计上的创新点，测试所获得的排量与压降之间的关系曲线可指导冲击器的使用。生产性试验证明该冲击器工作稳定，可大幅度提高硬地层钻井效率，克服钻柱振动，延长钻柱的使用寿命，具有良好应用前景。  相似文献   

A mathematical hysteretic model for elastomeric isolation bearings     

J. S. Hwang  J. D. Wu  T.‐C. Pan  G. Yang 《地震工程与结构动力学》2002,31(4):771-789

An analytical model for high damping elastomeric isolation bearings is presented in this paper. The model is used to describe mathematically the damping force and restoring force of the rubber material and bearing. Ten parameters to be identified from cyclic loading tests are included in the model. The sensitivity of the ten parameters in affecting the model is examined. These ten parameters are functions of a number of influence factors on the elastomer such as the rubber compound, Mullins effect, scragging effect, frequency, temperature and axial load. In this study, however, only the Mullins effect, scragging effect, frequency and temperature are investigated. Both material tests and shaking table tests were performed to validate the proposed model. Based on the comparison between the experimental and the analytical results, it is found that the proposed analytical model is capable of predicting the shear force–displacement hysteresis very accurately for both rubber material and bearing under cyclic loading reversals. The seismic response time histories of the bearing can also be captured, using the proposed analytical model, with a practically acceptable precision. Copyright © 2002 John Wiley & Sons, Ltd.  相似文献