Rerouting of Middle Bench Conveyor System in Mine for Optimization of Length and Power Consumption

In Neyveli Lignite Corporation, belt conveyors are used for transporting coal and overburden soil from mines to storage yards and dump yards respectively. Conveyor belt with carrying capacity upto 20,000T/hour is used for transportation of materials. The power consumption of the conveyor system depends on the length of the conveyor. Power consumption is high for a long routed conveyor system and less for a short routed conveyor system. The conveyor system is rerouted to the shortest possible way for optimizing length and power consumption of the conveyor system. By this rerouting, the cost of power consumption will be reduced. Keywords: conveyor system, power consumption, rerouting, mine, length

Effect of Thickness and Compaction Degree of Overburden Soil on Radon Reduction for Uranium Tailings Reservoir

The thickness and compaction degree of the overburden soil on the beach of the uranium tailings reservoir has an important influence on the radon reduction rate. A theoretical model of radon exhalation is established and an experimental device is designed. The main results are as follows. (1) The radon reduction rate increases with the increase of thickness. When the soil compaction degree is 85.5%, 90.2%, and 94.8%, the radon reduction efficiency increases significantly when the thickness increases from 5 cm to 10 cm, and when the soil thickness is over 10 cm, the increase of radon reduction efficiency tends to be stable. When the compaction degree is 80.9%, the radon reduction rate always increases obviously with the increase of the thickness of the overburden soil, but the increase rate shows a downward trend. (2) The radon reduction rate increases gradually with the increase of compaction degree, and the increasing trend becomes less obvious when the compaction degree is more than 85.5%. Besides, the effect of the change of soil compaction on radon reduction rate decreases with the increase of soil thickness. The calculation formulas about the effect of thickness and compaction degree on radon reduction rate can guide the design and construction of radiation protection of uranium tailings reservoir.

Validation of Coupled FDM-DEM Approach on the Soil-Raft Foundation Interaction Subjected to Normal Faulting

<p>Recent earthquake events have shown that besides the strong ground motions, the coseismic faulting often caused substantial ground deformation and destructions of near-fault structures. In Taiwan, many high-rise buildings with raft foundation are close to the active fault due to the dense population. The Shanchiao Fault, which is a famous active fault, is the potentially dangerous normal fault to the capital of Taiwan (Taipei). This study aims to use coupled FDM-DEM approach for parametrically analyzing the soil-raft foundation interaction subjected to normal faulting. The coupled FDM-DEM approach includes two numerical frameworks: the DEM-based model to capture the deformation behavior of overburden soil, and the FDM-based model to investigate the responses of raft foundation. The analytical approach was first verified by three  benchmark cases and theoretical solutions. After the verification, a series of small-scale sandbox model was used to validate the performance of the coupled FDM-DEM model in simulating deformation behaviors of overburden soil and structure elements. The full-scale numerical models were then built to understand the effects of relative location between the fault tip and foundation in the normal fault-soil-raft foundation behavior. Preliminary results show that the raft foundation located above the fault tip suffered to greater displacement, rotation, and inclination due to the intense deformation of the triangular shear zone in the overburden soil. The raft foundation also exhibited distortion during faulting. Based on the results, we suggest different adaptive strategies for the raft foundation located on foot wall and hanging wall if the buildings are necessary to be constructed within the active fault zone. It is the first time that the coupled FDM-DEM approach has been carefully validated and applied to study the normal fault-soil-raft foundation problems. The novel numerical framework is expected to contribute to design aids in future practical engineering.</p><p><strong>Keywords</strong>: Coupled FDM-DEM approach; normal faulting; ground deformation; soil-foundation interaction; raft foundation.</p>

Evaluation of induced trench twin culverts constructed in deep fill

When culverts are installed beneath high embankments, earth loads become excessive and the induced trench construction method is a viable design option to reduce the culvert loads to acceptable levels. However, limited field studies evaluating the performance of induced trench twin culverts are reported in the literature and the practicality and effectiveness of the induced trench construction method (in general) has been subject to recent criticism. This paper describes the performance of twin 3048 mm inside-diameter reinforced concrete culverts constructed with an induced trench beneath 15.3 m of fill. Research instruments and autonomous data acquisition systems were installed during construction to monitor (i) culvert earth pressures, (ii) embankment deformations, and (iii) groundwater elevations in the vicinity of the compressible fill. The experimental observations recorded throughout the construction phase are presented herein; the embankment deformations are indicative of effective positive arching within the induced trench region, and the average earth pressure at the culvert crown was reduced to approximately 48% of the overburden soil pressure. The experimental data are compared with those reported in the literature by others, and the conclusions attained from this study demonstrate the effectiveness of the induced trench construction method.

Influence of surface footing loading on soil arching above multiple buried structures in transparent sand

Constructing a new buried structure nearby an existing one or constructing multiple buried structures in close proximity may change overburden stresses, induce ground movement, and affect soil–structure interaction. Such issues become more complex when these nearby buried structures are subjected to surface cyclic footing loading. Cyclic loading is expected to have different influences on the buried structures from static loading. This paper presents two-dimensional trapdoor tests with transparent soil to investigate the influences of static versus cyclic surface loading, number of trapdoors, overburden soil height, and load frequency on soil arching above single or multiple adjacent buried structures. The particle image velocimetry technique was adopted to monitor soil movements during testing. The test results showed that soil arching degraded more under cyclic loading than under static loading. The interaction of buried structures, the thin overburden soil, and the high load frequency accelerated soil arching degradation and induced larger ground surface displacement.

Will a buried composite pipeline system fail at its joints under the effects of overburden soil, pipe operating pressurization, and traffic loads?

In real world applications, buried pipelines span across great lengths. It is inevitable that certain sections of a buried pipeline experience external loads in addition to top soil overburden, such as weights of aboveground buildings and traffic loads located directly above these sections. The present study investigated the effects of overburden soil, pipe internal pressurization, and traffic loads on fiber-reinforced plastic pipelines at various pipe sections with particular emphasis on pipe joints using finite element method. This study includes realistic modeling of traffic loading on service road running across a buried pipeline system, consisting of straight, bent, and joint sections. Our results also revealed that surcharge loading might not be a predominant factor in pipe failure or leakage issues as compared to the cyclic pipe internal pressurization. Moreover, it was also confirmed in our study that the pipe joint remained as the most critical region for pipe failure or leakage issues.