排序方式： 共有7条查询结果，搜索用时 15 毫秒
1
1.
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
2.
Hydraulic fills used in Australian mines have similar grain size distributions whilst having quite different specific gravity
values, typically in the range of 2.7–4.4. When produced and distributed in slurry at 65–75% by solid content, they settle
to produce fills with similar geotechnical characteristics. The fills under investigation have been found to settle, in the
laboratory, to a dry density of about 0.56 × specific gravity, a saturation water content of about 17–34%, and a porosity
of 37–49%. A quick estimate of the optimum water content that gives the minimum porosity may be obtained by locating the intersection
of the saturation curve and minimum porosity line, which may simply be done on a water content vs. porosity plot. However,
transportability of the slurry requires it to be mixed at water content substantially greater than the optimum water content.
As the tailings settle out of suspension, they settle to relative density of 50–80%. This paper shows that the current empirical
relationships relating relative density and N-value to friction angle for sands will significantly underestimate the friction angle of the hydraulic fills. Based on limited
experimental data, a unique relationship between relative density and friction angle is proposed for hydraulic fills placed
in some Australian mines. 相似文献
3.
Inadequate drainage has been attributed as the major cause of failure of several hydraulic fill stopes that have claimed lives.
Therefore it is necessary to be able to predict the pore water pressure developments and flow rates throughout the filling
operation. There are computer programmes that can simulate the hydraulic filling of a mine stope and enable computations of
the pore water pressures, flow rates and hydraulic gradients at any time. This paper presents a simple analytical solution
for estimating the maximum pore water pressure within the stope, flow rate and the hydraulic gradients at the entry and exit.
The proposed solutions are verified against solutions derived from FLAC, a finite difference software, and the agreement is
found to be excellent. A simple equation for the hydraulic gradient at the top of the stope, as a function of the height of
water within the fill, is also presented. 相似文献
4.
A good understanding of the pore water pressure developments within the hydraulic fill stope and the discharge through the
drain is essential for improving the designs of barricades and the safety in the mines. A finite difference software FLAC
was used to study the drainage and pore water pressure developments within a two dimensional rectangular stope with a single
drain at the bottom. Using the method of fragment, a simple solution was proposed for determining the discharge and the maximum
pore water pressure within the stope, when the height of water is greater than the width of the stope. The predictions are
within 1% of those obtained from FLAC. 相似文献
5.
Materials properties of barricade bricks for mining applications 总被引：1，自引：0，他引：1
Christopher C. Berndt Kirralee J. Rankine Nagaratnam Sivakugan 《Geotechnical and Geological Engineering》2007,25(4):449-471
Barricade bricks are fundamental to the safe operation of a mining site. Past failures have lead to loss of life and reduced
mine efficiency or even shut down. The fundamental material property that determines the operational characteristics of barricade
bricks is their permeability, which must be tailored to suit the operational environment of the mine. The ability of the barricade
to control the hydraulic pressure within a stope application is crucial for safety and economic returns. In the current work
practical barricade bricks were tested for permeability. As well, the strength and modulus of bricks were measured after being
soaked in water for either 7 or 90 days so that a measure of their engineering functionality could be determined. The primary
conclusions of this work are as follows. There was substantial deviation in permeability between bricks; however, the average
permeability of the barricade bricks was several orders of magnitude larger than the values obtained for the hydraulic fill.
This difference indicates that modelling efforts can assume that the barricade does not contribute to the pore pressure development
within the fill. Hence the drainage of the system is not related to the permeability of these bricks provided that the barricades
are built from the bricks in such a way that the construction or future migration of fines from the fill does not impede the
drainage performance.
相似文献
| Christopher C. BerndtEmail: |
6.
7.
Paste fill is the newest form of backfill material in the spectrum available to international mines and is made from full
mill tailings. Tailings have an effective grain size of approximately 5 μm and are combined with a small portion of binder
and water to make paste. It is deposited into the voids created by mining which are referred to as stopes. The empty voids
are approximated as vertical rectangular prisms, with plan dimensions of 15–40 m and heights of 100 m or more. Backfilling
of mined stopes provide an increased level of local and regional stability to the ore body, as well as providing a suitable
and economic dump of mining related waste. Paste is a relatively new technology in the mining industry and a review of the
physical properties and mechanical fill behaviour was considered pertinent. 相似文献
1