Abstract Researchers from the National Institute for Occupational Safety and Health (NIOSH) Spokane Mining Research Division (SMRD) are evaluating the comparative performances of shotcrete support systems currently utilized in underground metal mining. The SMRD Metal Ground Control Team in Spokane, Washington USA, is exploring applications of photogrammetry for visual performance assessment of shotcrete reinforcement utilized in a support system. This paper describes how photogrammetry is being used to correlate support deformation with remaining support system capacity in laboratory tests. These systems include various types of shotcrete reinforcement (fibers, wire meshes) and bolts. This study demonstrates how different installation sequences (i.e., mesh/bolts/shotcrete versus shotcrete/mesh/bolts) affect the support capacity of the system. Quasi-static, high energy, high deformation tests were performed for six different sequencing scenarios. This research supplements previous studies into photogrammetric and laser scanning methods, and enhances how shotcrete reinforcement system deformation may be understood to maximize miner safety. NIOSH SMRD is committed to improving the health and safety of miners through innovative research and applications of technology. 1. Introduction 1.1 Ground control testing Underground metal mines typically use a combination of rock bolts, wire-mesh, and shotcrete to support excavations. While good rock bolt performance is essential to successful ground control, the containment and support of the ground between the bolts is equally important. Shotcrete and mesh, in various combinations and with other components, are often used to provide this support, and thus combine with the rock bolts to form an overall shotcrete support system. Understanding how these systems respond to induced stresses is therefore required for successful ground control planning. However, the order in which the system components are installed may differ depending on a variety of factors, and the resulting performance of identical systems, in terms of components, may also differ. The current study accounts for the differing expectations of these shotcrete support systems depending on the order of system component installation, and how deformation-based monitoring of these shotcrete systems can be used to assess performance.

Abstract Sequential excavation method (SEM) is commonly used for the underground rock cavern construction. One of the major focuses in the SEM process is the selection of the excavation sequence parameters including the subdivision of cavern cross-section and the round length. In this paper, the parameters of excavation design were going to be optimized by adopting the approximate excavation performance using the response surface generated by artificial neural network (ANN) model. Firstly, the training data was generated using numerical studies. Multi-staged 2D plain strain models were adopted to conduct the numerical simulations, and further associated with tunnel advance processes using the convergence and confinement method (CCM). The parameter studies were involving the studies of rock types, cavern sizes, excavation methods and cavern performance. Then, a 3-layer ANN model was used to mapping the relationship between the excavation design parameters and the tunnel performance. At last, by adopting the proposed ANN model with the optimizing function in EXCEL, a revised excavation chart was proposed to help the engineers to quickly find the optimized sequential excavation parameters. 1. Introduction The sequential excavation method (SEM) is widely used for the construction of rock caverns, shafts and other underground structures. It takes advantage of the capacity of the rock mass to support itself by deliberately controlling and adjusting the stress and deformation field which takes place in the surrounding rock mass during the excavation. Federal highway administration (2009) has proposed four essential processes in the SEM design, include: the classification of ground condition and excavation, the definition of excavation method and support classes, the instrumentation and monitoring, and the ground improvement prior to rock cavern excavation. One of the major focuses in the SEM process is the selection of the excavation sequence parameters including the subdivision of cavern cross-section, the round length (maximum unsupported excavation length) and the supports installation time. Subdividing the cavern cross-sections could heavily reduce the risk of the cavern instability during excavation (Graziani et al., 2005; Lunardi and Barla, 2014; Zhang and Goh, 2012). However, too many subdivisions will increase the required equipment and manpower and thus increase total construction costs. To optimize the excavation designs, it is important to approximate the performance of tunneling under specified SEM parameters. Response surface method (RSM) has been proposed as a useful method to predict the tunneling performance. It has been studied by researchers to present the performance in explicit form (Lü et al. 2017; Hamrouni et al, 2018). Artificial neural network (ANN) is one of the effective ways to approximate the response surface. It has been widely used in data analysis in civil engineering (Zhao and Ren, 2002; Zhao et al, 2008). Essentially, the network is trained by adapting the weights and biases using optimization methods to minimize the mean square error between the predicted and the target values. Some commercial codes such as MATLAB have provided for convenient use of ANN.

Abstract With increasing competition for land usage in Singapore, there is a need for more extensive use of underground space in Singapore, which can help to free up more surface land for other better usage. An Underground Master Plan Task Force was formed by the Ministry of National Development with active participation from key government agencies together with the planners to formulate a Master plan and also to develop guidelines on the use of underground spaces. In view of the need to better study the potential of deep underground developments, the Singapore Geological Office (currently renamed as the Geological and Underground Projects Department) was set up within Building Construction Authority (BCA) to investigate the country's geology and identify sites which are suitable for such developments. The first part of the paper covers how the Geological Office plans and conducts the geological investigation works. The second part of the paper discusses the geosurvey results, especially the variability of the rock mass properties in one particular area revealed from the investigation works. Finally, the paper demonstrates how the variability and uncertainty of the rock mass can be accounted for using a probabilistic approach for assessment, and the results would provide a better insight of the areas suitable for cavern. 1. Introduction As Singapore has a land area of only 710km 2 , there is greater need to look into utilisation of underground space and this has become an integral part of Singapore's strategy for space creation in the future with the ever-increasing competition for land use in this small island state. The Urban Redevelopment Authority of Singapore (URA) has hence put forth the creation of underground rock cavern as one of the land optimising approaches in their underground masterplan. Ever since Brown raised the potentiality of having underground spaces to be built in Singapore in 1989 (Zhou & Cai, 2011), many deep underground feasibility studies have been conducted. To date, Singapore has successfully constructed the Underground Ammunition Facility (UAF) in 2008, which freed up 300 hectares of land above ground for other use (Wan, 2015), as well as South-East Asia's first commercial underground liquid hydrocarbon storage facility at Jurong Island (i.e. Jurong Rock Caverns) built in 2014 and it free up 60 hectares of usable land above ground (Chia, 2014). Adding to the list of activities and development on deep underground space in Singapore since 1990 (Lui, Zhao and Zhou, 2013), the Building and Construction Authority of Singapore (BCA) set up the Singapore Geological Office (currently renamed as the Geological and Underground Projects Department (GUPD)) to investigate and identify the country's deep geology characteristics and identify sites suitable for such developments to support URA's development of the underground masterplan (Lim, 2018).

Abstract The behaviour of jointed rock mass is highly dependent on the properties of rock joints. One of the most important property used in identifying the behaviour and performance of rockmass is the joint stiffness and the deformation behaviour of tunnels in jointed rocks is dependent on this joint stiffness. As the stiffness parameter rises to a very high value, the joint attains the strength comparable to an intact rock and behaves as a welded joint. Many studies under static as well as in dynamic conditions have been conducted to understand the effect of joint stiffness on rock mass behaviour. In this study, the wave propagation characteristics and transmission coefficient have been studied on single jointed rock mass under the influence of varying joint stiffness using Universal Distinct Element codes (UDEC). The analysis has been further extended to understand the effect of joint stiffness on the tunnel in jointed rocks with shake table model testing and subsequent comparison with dynamic loading with a sinusoidal input. A parametric study is performed to understand the effect of joint normal stiffness and joint shear stiffness on the performance of jointed rock mass is investigated. It is found that the tunnel deformation is linearly varies with the joint normal stiffness under static conditions but it varies exponentially under dynamic loads. 1. Introduction Rock mass encountered in the field is usually found with joints. These joints being unavoidable, needs special attention in the execution of big rock engineering projects. The presence of joints reduces the strength of rocks and the joint strength becomes the factor determining the performance of the rock mass. The main factor affecting the strength of the joints is the joint stiffness parameter. Unlike many other rock parameters, the estimation of joint stiffness is difficult mainly due to the absence of any proper specifications or guidelines (Kutalilake et al., 2016). A lot of research has been done on laboratory experiments to identify the joint displacement behaviour (Goodman, 1974, 1976; Bandis, 1983; Barton and Bandis, 1980, Jing et al., 1994). Joint normal stiffness (Goodman, 1968) can be defined as the ratio joint normal stress to the normal displacement. Finding the joint stiffness in a rock mass medium is considerably tough and studies established the importance of insitu stresses on the joint normal stiffness. Many linear and nonlinear models were developed to define the relationship between joint stress and joint displacements. Study by Hsuing et. al. (1993) highlighted the importance of normal stress in joint normal stiffness and joint shear stiffness and emphasized on the importance of normal stiffness on shear displacement. Most of the studies being done under laboratory conditions to understand the joint behaviour, Barton (1981) gave an equation correlating joint stiffness to the rock mass modulus and intact rock modulus.

Abstract The three most predominant methods for hard rock excavation and fragmentation are the use of explosives, mechanical impact/cutting and hydraulic fracturing. However, those methods have inherent drawbacks, such as non-applicability or poor performance in extremely hard and abrasive rocks. Novel rock fracturing and fragmentation methods are in need to either work individually or in combined forms to break rocks. Research shows that some rock forming minerals and water can be heated up rapidly by microwave, to induce microcracks and fractures in rocks. Microwave therefore can be regarded as a promising technology of hard rock fracturing and fragmentation, with the potential of energy and cost efficiency. This keynote first provides a brief review of the research on microwave effects on rock fracturing, followed by descriptions of experimental studies of crack formation in different rocks treated by a low power industrial microwave. Possible fracturing mechanisms by microwave treatment are discussed, and the applications of microwave treatment assisting rock excavation coupled with mechanical means are outlined at the end of this keynote. 1. Introduction Fracturing and fragmentation of hard rocks is one of the most important tasks in rock engineering in the fields of mining, petroleum, and tunneling industries. While drilling and blasting remains to be the most powerful and effective method to break hard rocks, the uses of explosives are often limited by various constraints. Hard rocks are excavated and fractured by other means, including mechanical cutting and drilling, hydraulic fracturing and heating. Mechanical cutting becomes a dominant method for large scale rock excavation, particularly in tunneling, with the extensive uses of tunnel boring machines (TBMs) and roadheaders. However, hard rocks can pose great challenges to mechanical cutting and fracturing due to the extreme hardness and abrasiveness, which often lead to reduced advance rates and increased cutting tool wear. Other methods of rock fracturing and cutting have been investigated, including waterjet, laser, millimeter wave and microwave, as a sole mean for rock cutting or in combination with mechanical excavation. New technologies explored for possible use of rock fracturing and cutting are the electrical methods and the electromagnetic (EM) methods. The electrical methods include plasma blasting, electron beam and electric current. The EM methods use electromagnetic waves, including laser cutting, infrared irradiation, torch heating, and microwave heating. Mostly those technologies are investigated as a sole mean for rock fracturing or vaporization. The study presented in this keynote uses microwave technology to induce microcracks in hard rocks hence to ease the mechanical excavation. The objective is on adapting and developing low powered microwave tools to assist mechanical excavation of hard rocks, as an economical alternative.

Abstract Ground control condition is one of the most important issues in mechanized longwall mining. The Alpu lignite field in Turkey presents a challenging situation because of its thick, weak and clay content surrounding strata. The purpose of this study is to figure out the ground control condition of the study area by the following steps: classification of the geotechnical units, rock mass classification, cavability index, required shield capacity and floor bearing capacity. Geotechnical classification of the strata layers and rock mass classification was determined by the lithology of the boreholes and laboratory test analyses of them. Caving behavior of the roof strata was predicted by the polish scientists method. Then by applying the "US National Institute for Occupational Safety and Health (NIOSH)" roof rating system at possible roof strata, results were compared. Roof strata were classified as "immediately caving" strata in all production alternatives. Required shield capacity was estimated by detached block method. The caving height was calculated based on the bulking factor of the lignite and roof strata. Low strength floor strata act as a limitation to mining height increasing in all production alternative. Possible mining height was determined as five and six meters with the LTCC method. Required shield capacity in each production alternative was raised by increasing cutting height. To avoid failure during the production, supports should be advance with pressure by touching the roof and soon after the cutting. In addition, cutting height should be limited to the critical height. 1. Introduction Since the 1980; longwall mining has become rival to many surface mining operation performances by achieving more safety, high production and most productive in underground coal mining (Galvin, 2016). The longwall mining method is preferred for stratiform and flat lying orebody and orebody dip needed to be less than 20°. Under the hydraulic roof support, coal is cut with shearer and the broken cut coal is loaded by armored face conveyor (AFC) to the belt conveyor which is parallel to the face advance (Brady and Brown, 1985). Longwall top coal caving (LTCC) is a comparatively new method for mining thick coal seams. LTCC currently has reached high production and efficiency in longwall mining mostly in China. The procedure is almost the same as the traditional longwall mining method. The Shearer cuts coal seam from the lower section of it onto AFC that installed near the cutting face and in front of the hydraulic support. A rear conveyor belt is added behind the support in the modern LTCC, so the caved coal in the upper part of the seam can flow to the rear conveyor from the canal which is controlled by the rear canopy of the support (Alehossein and Poulsen, 2010). A schematic model of the top coal caving method is illustrated in Fig. 1.

Abstract It has become more important for communities to utilize locally available renewable energy sources. The use of renewable energy can reduce environmental impacts and potentially provide long-term cost savings for communities. In this paper, the authors propose a system that could cool buildings in summer and melt snow on the pedestrian sidewalks in winter using an abandoned underground mine and a hot spring in Idaho Springs, Colorado. In the proposed system, an underground mine would be used as cold thermal energy storage, and the heat of geothermal hot fluid transported from the hot spring would be re-used to melt snow in the historic downtown. To assess the feasibility of the proposed system, we conducted a series of temperature measurements at the Edgar Mine (Colorado School of Mines' Experimental Mine) and heat transfer analyses of the geothermal hot fluid flowing through pipes that will be buried in the ground under the city. The temperature measurements proved that the temperature of the underground mine was low so that we could store cold groundwater for use in summer. Furthermore, the temperature profiles of two different tunnels in the Edgar Mine were discussed to determine the most appropriate place to store cold groundwater for summer use. In the heat transfer analyses, the heat loss of the geothermal hot fluid during its transportation was calculated, and then the heat requirement for snow melting and heat supply from the geothermal hot fluid were compared. It was concluded that the heat supply in the present situation was not sufficient enough to melt snow in the whole area of the historic downtown. However, the result indicated that the proposed snow melting system could be realizable if the snow melting area is limited or additional geothermal wells are drilled. We hope this case study will serve as an example of the concept of "local consumption of locally available energy". Many communities in the world do not fully utilize thermal resources in the ground. If such communities start utilizing them in a socially and environmentally responsible manner, it will contribute more to globally sustainable development for mankind.

Abstract Carbon Dioxide (CO 2 ) sequestration in deep coal seams is a potential mitigation option for global warming. In deep coal seams, the temperature is higher (>40°C) which makes the kinetic energy of the gas molecules to be increased. Accordingly, it increases the rate of diffusion and results in reduction of adsorption capacity that affects the coal gas permeability. Among several previous works conducted regarding the temperature effect for coal gas permeability, the attention paid for brown coal is very less which enhance the necessity of a detailed study. Therefore, the main objective of this study is to investigate the effect of temperature on the permeability of Victorian Brown Coal. A series of tri-axial experiments was conducted on brown coal specimens that were collected from Latrobe Valley basin, Victoria. Permeability tests were carried out under 10 MPa confinement for two different temperatures (25 and 40°C). Both CO 2 and N 2 were injected to the sample in various injecting pressures to obtain a proper comparison between the reactive and non-reactive gas permeability. According to the experimental results, CO 2 permeability of coal decreases for higher injecting pressures (at 8 MPa) at lower temperatures (less than 40 °C), due to the process of swelling occurs inside the coal sample during the CO 2 injection. However, the influence of temperature on N 2 permeability was negligible compared to the CO 2 permeability. Basically it may because; N2 is a nonreactive gas which does not make any adsorption or swelling effect in coal matrix like CO 2 .

ABSTRACT Upper Gotvand Dam in Khuzestan province, 30 km. north-west Shushtar city and 12 km. Gotvand city is Located and the last dam on the Karun River will be constructed. The dam has 180 meters height, with clay core type. One of the executive activities of this dam is excavating and supporting surge shaft system. The aim of these excavations is balance between power plant and waterway system and also acts to prevent of water hammer. These shafts are located in the Bakhtiari Formation (Conglomerate rocks) and the Lhbary formation (conglomerate- silt Stone and clay stone with the thin sandstone layer and filling some kind of gypsum and clay). Project consists of four shafts with a diameter about 18 meters and about 60 meters height. Because synchronization explosion (as blasting) and concreting, effect of waves and vibrations is inevitable on the necessity of concrete monitoring by seismograph systems. In this paper, data from seismograph machines around surge shaft and using existing standards, in relation to controlled explosions adjacent concrete structures based on the distance from center of blasting and charge per delay is derived.

ABSTRACT Coal mining companies in Indonesia are obliged to perform reclamation effort to achieve sustainability post mining land use and as much as possible to restore after mined land to the initial condition. The main factor that normally affects the reclamation success is the loss of soil fertility due to soil erosion. Soil erosion causes the loss of top soil layer which has a very important role in plant growth because this layer contains the highest concentration of organic matters and microorganisms. Soil erosion is influenced by climate properties, soil properties, topographic properties, cropping management factor and human intervention in conservation practice factor. The aim of this research is to analyze effect of soil properties and slope to the soil erosion in Indonesia coal mining reclamation area using rainfall simulator. This research was conducted using three types of soil texture including clay, clay loam and silty clay loam; also conducted using three types of slope including 2°, 15°, and 30°. According to research result, the amount of soil loss increased with the increasing angle of slope and increasing of clay content.

Abstract: Explosive welding is planned in an abandon drift which is approximately 10m radius and 9m height. According to the plan the amount of explosive, ANFO will be up to 1000kg per stage. Before the explosive welding experiment, the environmental analysis especially about the air-blast overpressure should be concerned because that the explosive welding is methodologically similar to open pit blasting. The air-blast overpressure could give damages to nearby structures and cause human annoyance. Normally in tunnels and drifts in a mine, a damping ratio of the overpressure is lower than open space because that reflected pressures are easily get together in a sealed condition. In this study we investigate a safety of nearby pillar and upper wall from the overpressure in a drift using the overpressure estimate equations from CONWEP and DDESB. As the results, strength of composed limestone in the drift is higher than the overpressure in a common distance. However the overpressure can cause a weakness of nearby pillar and roof in a drift which contain narrow parallel joints. 1. INTRODUCTION An explosive welding was designed in the mining drift. The explosive welding to the nearest pillar was approximately 20m and the ceiling height was 9m. The mining drift 15m×7m was excavated to ventilate gases generated from explosive welding. ANFO is designed to use explosive welding up to 1000 kg in phase. Peak overpressures, caused by explosive welding, are expected to rapidly propagate to the air with hemispherical around. It can also give damage to the nearest pillar and its celling. Thus safety factor analysis should be considered beforehand. In this study, the three equations, a normal equation from large explosion experiment, CONWEP (Convention Weapons Effects Program) overpressure equation depending on distance from an explosion and DDESB (Department of Defense Explosives Safety Board) overpressure equation estimating overpressures by efficiency volume are used for estimating overpressures generating from blasting welding. 2. THE PROPAGATION OF OVERPRESSURE BY AN EXPLOSION FROM THE GROUND If an explosive explodes from the ground or near surfaces, the first overpressure will be reflected to the ground soon. Furthermore the initial and reflected overpressures are going to combine into one single wave which will propagate simultaneously hemispherically [1]. 3. EXPLOSION OVERPRESSURE ESTIMATIONS 3.1 TNT equivalency As ANFO was considered for explosive welding at this mine equivalent weights of TNT which is relative to effective charge weights of ANFO should be considered in order to estimate overpressure within those equations. 3.2 Overpressure estimations The Peak overpressure P0 estimated with CONWEP equation can be calculated in the following equation [2]. The blasting welding has many analogies with ground explosions. Therefore reflected over pressures should be concerned since the overpressure will be propagating hemispherically. As a results, if 1000kg of ANFO is used for explosive welding, the peak overpressure which affects to pillars 50m away from the explosion is calculated to 0.03 MPa. Furthermore the peak overpressure onto the roof which is located on the distance of 9m from the explosion is calculated to be 1.36 MPa.

In the Western Ghats during rainy season, landslides cause extensive damage to life and property and also blocks many communication routes. Geological Survey of India being Nodal agency for landslide studies in India, has taken up the geotechnical studies of these landslides, in order to understand landslide causes, mechanism, suggest remedial measures and ultimately to develop an early warning system. The landslide at Hilary village was chosen as a model to conduct site specific studies, which includes geotechnical mapping, preparation of L- sections and collection of a few undisturbed and disturbed soil samples for analysis. The hill slopes are essentially covered with highly porous lat erotic soil which permits ample water infiltration at much deeper levels making the slope highly unstable on super-saturation during heavy downpour. Rise in flow level of stream lets facilitates gradual erosion of toe support which ultimately facilitates downward movement of super-saturated overburden situated on the inclined slope. Modification of slopes for practicing agriculture, slope loading by construction and alteration of natural drainage has contributed to the frequent landslide incidences in the Western Ghats. 1. INTRODUCTION Hilary (17°54'55" N: 73°45'45" E, too. no. 47 G/13) is a small village located in Tensile Mahabaleshwar, District Sahara, Maharashtra. The average annual rainfall ranges between 2500 to 3500 mm out of which, June, July and August accounts for most of the precipitation. Vegetation is thick to moderate containing tropical flora. The area exhibits highly rugged & closely dissected hilly terrain. Main topographic features are flat plateau tops, moderately sloping to vertical scarps, „V" shaped valleys and step like terraces characterized by sudden break in slope formed due to Deccan Basalt lava flow contacts. General pattern of land use is, location of small villages, hamlets and residential dwellings at the higher contours occupied by flat Deccan Trap plateau tops. Lower elevations and the hill slopes are occupied by agricultural lands. Agriculture is the main occupation and terrace cultivation along the hill slopes is the most common type of agricultural practice. Geological setup of the study area The area exposes about 250 m thick pile of Deccan Trap lava flows of Mahabaleshwar Formation of Sahyadri Group. The lava flows are essentially a'a type and moderately to highly porphyritic. These lava flows are divided into three groups. The Landslide area is mainly occupied by Flow Group III (Flows 21 to 29). These lava flows are jointed with prominent sets trend NISSE, N-S, NE-SW having vertical to sub-vertical dips. 2. SITE SPECIFIC STUDIES: Site specific geotechnical investigation includes study of general topography, lithology and geological setup, different lido units in the affected area, their probable thickness, study of the failing slope & qualitative strength of slope forming materials, anthropogenic activities, ground deformations, nature of movement and possible reasons for the failure. 2.1 Lithology at the site and material involved It comprises 4 types of lido units. Late rite lat erotic soil/clay (lit homage) highly weathered basalt & fresh basalt. Late rite occurs as patches at different levels.

ABSTRACT: At Moyna Hydro-electric Project, an 80MW powerhouse is currently proposed at the left dam foot of Moyna river dam in Maharashtra. The underground powerhouse cavern needed for housing the two turbine units of 2 X 40MW is designed using three-dimensional numerical modelling. Three possible geometries for the powerhouse are designed considering the weaker rock mass layers of Volcanic Becca existing in the vicinity of the proposed cavern. These configurations are simulated in FLAC3D software. Their stability is analysed using Hook and Brown rock mass failure criterion. Taking cues from the stability predicted for the three configurations, a final configuration is designed. The final configuration is further subjected to three dimensional modelling and stability analysis. The cavern is expected to have good overall stability. The crown region, since it will be located in stronger Compact Basalt rock layer, will have superior stability. However, the cavern will have weaker sides, where Volcanic Becca will be exposed. A support plan for the entire cavern is also designed incorporating 100mm thick steel fire reinforced shotcrete (SIRS) and 6.0m long full column grouted resin bolts. 1.0 INTRODUCTION Moyna Hydro-electric Project of Maharashtra State Government produces electricity of the order of 2000MW in four stages. This environmental friendly and cheap power generation caters to the energy demands of the neighbouring region. As an extension of Stage IV, an 80 MW (2x40 MW) capacity powerhouse is proposed at the Moyna dam foot at the left bank of the Moyna River. Underground powerhouse chambers are proposed for power generation. From the geological survey conducted by Moyna Project authorities, the rock types existing in this vicinity was found to be Deccan Trap Basalts, viz. 2.0 ROCK PROPERTIES AND INCITE STRESS The intact rock properties tested earlier by CAPES (Anon (2004) and Anon (2005)) and rock mass parameters such as RM (Bieniawski (1976)) for compact basalt and volcanic Becca are given in Table 1. The Hook and Brown rock mass parameters are also evaluated (Hook and Brown (1980)) and given in the table since they are to be used in the numerical modelling. 3.0 DESIGN STRATEGY Three optional configurations were initially chosen to comparatively analyze the stability scenario. Depending on their stability, the most stable configuration shall be chosen as the final powerhouse design. The three configurations modelled for their stability analysis has the following salient features. Configuration 1: A powerhouse cavern of 21m width, with crown level at 599m EL and springing level at 592.5m EL A valve house of 10m width, with axis at 600 to that of the powerhouse cavern, with crown level at 595.5m EL and springing level at 592.5m EL Configuration 2: A powerhouse cavern of 21m width, with crown level at 595m EL, and springing level at 588.5m EL A valve house of 10m width, with crown at 591.5m EL and springing level at 588.5m EL Configuration 3: A single powerhouse cavern of 25m width, with crown level at 595m EL and springing level at 588.5m EL, and without a valve house

Abstract: A novel engineered crib (ATLAS Crib), developed at Southern Illinois University Carbondale (SIUC), is a composite wood element designed to achieve improved strength, stiffness, and yield properties for cribs. The element uses approximately one-third less wood, weighs about 40 percent less, and offers less ventilation resistance than a conventional crib element. Installation and manual transport times are also reduced along with the risk of physical injury to miners during these operations. This paper presents comparative results of a field demonstration of ATLAS and conventional cribs. The two different cribs were installed in adjacent areas in a headgate return air course entry. They were monitored over an extended period while the current longwall face and the adjacent longwall face mined past the demonstration area. In the latter phase the cribs on the tailgate side were subjected to the highest possible load. In addition, eight (8) ATLAS cribs in four (4) crosscuts were also installed on the headgate side of the adjacent longwall panel next to the belt entry where they were subjected to very high loads. Structurally, ATLAS cribs performed well in both areas. Crib and roof-to-floor convergence data, as a function of distance from the face, were similar for both cribs. ATLAS cribs behaved stiffer than conventional cribs. ATLAS cribs also demonstrated ventilation advantages. Based on success during this study, a field demonstration over a 600-ft (182.88 m) length of tailgate entry has been recently completed. 1. INTRODUCTION Coal mines typically use wooden cribs to provide standing support between roof and floor. Cribs are more extensively used in longwall mining than in room-and-pillar mining. In longwall mining, they are used primarily to support gate, setup and bleeder entries and provide temporary support during the shield removal process when moving longwall equipment from one panel to the next. Although cribs have been used since the inception of mining, current usage is subject to the following disadvantages and/or limitations: Loading on the crib element is transverse to the wood grain resulting in low crib stiffness, which leads to low load carrying capacity and large deformations, The cross-section of the crib element is uniform along its entire length even though most stresses are around contact areas at either end, The uniform cross-section makes crib installation around irregular roof difficult, and Due to weight handling crib elements for placement at heights above four (4) feet (1.2 m) requires considerable effort. The primary author, with support from staff, developed a novel, engineered, composite wooden crib (ATLAS crib) in 2007 (see Figure 1) that overcomes most of the above disadvantages (Patent Pending). Results of preliminary testing at Illinois Coal Development Park (ICDP) and National Institute of Occupational Safety and Health (NIOSH) facilities (Gearhart, 2008) led to a field demonstration of ATLAS and conventional cribs in adjacent areas on an active longwall panel. The goal was to develop field performance data that would allow industry and regulatory agencies to make informed decisions regarding their use.

ABSTRACT Establishment of a base on the moon is an essential part of deep space missions. Any base on the moon should be self supporting, meaning the base should be able to mine, process, and store consumable resources on the moon to the extent possible. One of the most important aspects of establishing a base on the moon is the ability to excavate various formations for construction and mining purposes. Although the surface of the moon is covered by regolith and rock fragments, the layers below surface are more consolidated due to vibration caused by impacts or possibly freezing of condensed water vapors in the dark side and poles of the moon. The ice in the frozen soil, is possibly the most valuable resource on the moon and its excavation should be a part of advance planning of mining activities in space programs. This paper covers some of the background information on the properties of frozen regolith and discusses the extensive testing performed on lunar stimulant soils, including the compaction testing, measurement of compressive strength of frozen soil, indentation tests, and full scale cutting test of samples for development of a prototype lunar excavator. 1. Introduction Establishing self supporting base on the moon, which is a necessity for deep space missions, requires a constant supply of raw material that can preferably be mined on the moon surface. In addition, for construction of the base, certain excavation activities need to be performed in advance and they require machines that can cope with various types of material from soft surface regolith to consolidated soil, and possibly frozen soil. Excavation of such of distinctly variable material requires new and innovatively robust excavation system. The primary ore targeted at this time includes frozen regolith for extraction of moisture and water. Several concepts have been suggested for lunar excavation. This includes surface bucket excavator, shovels, surface miners, and roadmilling machines. Some of these machines are suitable for softer material or consolidated material when broken / fragmented, but not for rock or frozen soil. The rock like, harder formations do require an excavation system preferably with variable drum spacing to allow for excavation in various materials. To develop a viable cutting and excavation system, it is essential to develop an understanding of the characteristics of frozen regolith formations and its mechanical properties at surface and at depth. For this purpose, an extensive test plan was developed and executed within the past three years as a part of research study sponsored by NASA. This paper offers a review of the issues and general review of material properties for lunar regolith as well as the description and discussion of the testing plans and result of the studies on this subject, including the full scale cutting tests and design and testing of a prototype cutterhead for lunar excavation. 2. Background Several physical properties of dry lunar and Martian regolith have been directly measured or inferred from measurements.

ABSTRACT The swelling behavior of marls is a complex phenomenon. In saturated state, these materials present considerable volume changes resulting in swelling and mobilizing high swelling pressures. The behavior of swelling in rocks is controlled by numerous factors acting jointly and resulting in an effect whose main agent is frequently hard to identify. The design of tunnels in swelled grounds is a difficult task. Some problems are generally met for characterization and testing marls and for prediction the response of tunnel excavation and support loading. In this research we investigate the swelling behavior of marls and analyze the effect of their physical and mechanical properties on swelling considering to a case study. Our studied samples are red and green marls that are taken from Kohrang III water conveyance tunnel project, located in Chaharmahal Province in Iran (fig. 1). Physical and mechanical properties of these rocks were determined of some laboratory tests on samples which were derived from horizontal boreholes in digged parts of the tunnel. Our results showed the role of texture, structure and mineralogy in swelling potential in marls. The comparison between these two kinds of marls indicates that the major factor in swelling of marls is their hydration. Unloading has no impact on their swelling in comparison with their mineralogical composition and the type of clay minerals. Also the results indicate that red marls are more compacted with higher resistance. Finally experimental results confirme. 1. Introduction Most fine grained sedimentary rocks (marl) can be included in weak rocks group, which are widely distributed on ground surface and represent about 60% of sedimentary basin stratigraphy columns. The main components of these rocks are clay minerals with variable mineralogy. After clays the abundant minerals are quartz, calcite, and in minor proportions, pyrite and organic matters [2]. Among these rocks, swelling occurs commonly in materials composed mainly of clay minerals having expansive lattices, e.g., montmorillonite, illite, kaolinite and interstratified clay minerals. These materials, in general, have high liquidity limits and high plasticity [1, 5]. Marl's uniquely behavior is known to change under dry and wet conditions. In spite of its high strength in dry state, in saturated state, its resistance will drop considerably (reportedly by as much as 85%) and also exhibits collapsible, dispersive, swelling and low slake durability behavior when exposed to water [4]. Really, the effect of water on clay stone and marl is very important. In mines and tunnels that are excavated in clayey rocks, depend on type of clay minerals, water and humidity have straight effect on rate of excavation, because any phenomena has special problems in works. Swelling degree in marls depends on type of clay minerals too. Swelling decreases the resistance of marls and causes support destruction and sometime loss of life and property. Because of intricacy of the marls behavior, we decided to choose one of the digged segments in Kohrang III water conveyance tunnel that is located in marl formations.

Abstract Hamilton County, Ohio and the Greater Cincinnati area, including the tri-state region of northern Kentucky, southwestern Ohio, and southeastern Indiana have been plagued with extensive landslide activities, gaining the reputation of being one of the most landslide prone areas in the nation. The estimated cost of landslide related damages in Hamilton County alone is approximately $14 per capita per year. The underlying geology of Hamilton County (including substantial area of tri-state region) consists of shales and limestones of Middle and Late Ordovician age. By and large, the shale in the bedrock sequence disintegrates upon exposure to air and water whereby colluvial soils are formed. The overlying colluvium, derived from this weathering process, is unstable and have been historically slow moving and may be triggered by improperly constructed developments, heavy rains, and vibrations. The characteristics of these types of movements are considered herein along with laboratory direct shear test results. It is plausible that the stability analysis of colluvial slopes should be based on the residual shear strength. 1. Introduction Landslides are a persistent cause of damage to properties and nuisance to the public in several areas of Ohio. In particular, the economic impact from landslide damage is significant in Hamilton County and metropolitan Cincinnati area including the tri-state region of southwest Ohio, northern Kentucky, and southeast Indiana. During the period of 1927–30, landslides along Riverside, located west of downtown Cincinnati, destroyed nearly 40 homes, reported Von Schlichten in 1935 [3]. In 1974, a massive landslide was triggered on Mt. Adams in conjunction with the construction of Interstate Highway I-471 [4]. The cost of this single landslide has been estimated at ~44.5 million dollars (in 2005 dollars). In 1982, a map produced by the United States Geological Survey (USGS) revealed that an area within the tri-state region, up and down the Ohio River, was identified to have the highest landslide activities in the U.S. [1]. In 1996, a very wet year in tristate, it was publicized that the local engineers were working on over $10,000,000 in landslide repairs throughout Hamilton County [2]. During late spring of the same year (1996), another large landslide was triggered due to excessive rainfall in the Lawyers Pointe Subdivision in Anderson Township. The impact of the reference landslide was extensive, covered a surface area of approximately 10 acres, shifted nearly 500 ft long section of Lawyers Pointe Drive, and damaged utilities within the public right-of-way [5]. The above case histories present a potpourri of landslide incidences that exemplify the nature of recurrent mass movements in the tri-state region. Fittingly, the Greater Cincinnati has been referred to the "Landslide Capital of the Nation [6]." By and large, the topography of the area is characterized by a gently rolling upland surface, dissected by deep valley cuts of the Ohio River and its major tributaries along with flood plains and terraces of the rivers.

Abstract The underground shelter was built by Japanese Imperial Army in 1943 in pyroclastic flow deposits resulting from nearby Singgalang and Merapiti Volcanoes. The Singkarak Lake earthquake, took place as two large shocks on March 6, 2007 and caused extensive damage to slopes in Sianok Valley, in which the underground shelter is situated. This article is concerned with the seismic effects on the underground shelter and its seismic response during the earthquake. A brief outline of geography, geology, the layout of the underground shelter and the shape and size of underground openings are fırst described. Then the characteristics of the earthquake are briefly presented. And then the seismic effects on the underground shelter is described. In the fınal part, the results of some preliminary dynamic numerical simulations for the response of the underground shelter during the earthquake are explained and discussed. 1. Introduction The West Sumatra Province of Indonesia was struck by an earthquake on March 6, 2007, killing 73 people and caused heavy damage in the cities of Solok, Payah Kumbuh, Batusangkar and Simabur[1]. Two large events with a moment magnitude of 6.4 and 6.3 occurred at an interval two hours on March 6, 2007[2,3]. The first author visited the epicentral area between Bukit Tinggi and Solok in July, 2007. This earthquake induced many slope failures in sceneric Sianok Valley in Bukit Tinggi. This valley was created by Sumatra fault cutting through pyroclastic flow deposits from nearby Volcanoes. In Sianok Valley Japanese Imperial Army built an underground shelter in the same geological formation in 1943. While there were many extensive slope failures along the valley, the damage to the underground shelter was almost none, which may be of great value for understanding the behaviour of underground openings during earhquakes. This article is written with a sole purpose of pointing out the importance of underground shelter as a rock engineering structure in weak rock and to discuss the long-term behaviour and dynamic response during the earthquake. There is no doubt that the evaluation of the long-tem stability and dynamic response of this underground shelter from a rock engineering perspective would provide an important data set. The geography, geology, the layout of the underground shelter, the shape and size of underground openings and underground climate and ventilation are briefly described. Then the rock classifications and static stability of assessments of the underground shelter are presented. And then, the characteristics of the earthquake, the seismic effects on the underground shelter and the results of some preliminary dynamic numerical simulations are explained and discussed. 2. Geography and Geology This area is called the Padang Highland. A geologica1 sketch map of the area is shown in Figure 1, which was compiled by Sato [4] from the 1250000 quadrangle geologic maps published by the Geological Survey of Indonesia.

ABSTRACT: In the U.S., it was found that many of the reported ground control problems at longwall face were related to poor geologic conditions such as sandstone channel, faults, fold, and so on. In this study, the effects of sandstone channel on longwall face stability were evaluated using finite element models, which include a 600-ton two-leg real size shield model. It was found that, stress distribution in coal strata was greatly altered due to the existence of large-size sandstone channel in the roof. Cousequently, shield loading, roof sagging, face closure, floor heave, and floor punching were effected significantly as longwall face advanced toward the channel. Analysis reveals that shield leg started to yield from a certain distance (158 ft under specific condition in this study) and continued to yield until the longwall face entered low stress zone, which is below the channel body. Under this case, roof-to-floor convergence increased sharply and shield structure became unstable. Base on analysis results, a method used to determine optimum distance of longwall face from sandstone channel is proposed. I. INTRODUCTION With improvement of equipment reliability, geologic anomalies such as sandstone channel, crevasse splays, mold-and-cast structures, faults, folds etc are gradually found to be important factors that cause ground control problems, safety hazards, and production downtime at longwall face. Study shows that (Christopher, 1991), poor geological conditions are major safety hazard and source of downtime at a high percentage in longwall mines. Although sandstone channels were commonly encountered in underground longwall mine, design of ground control system at work face often ignores the effects of fandstone channel. Severe stability problems may be caused at longwall face by sandstone channel depositing in coal mine roof. Firstly, the margins of channel deposit are usually separated from surrounding strata by slickensided interfaces formed by differential compression (Valois, 1993). Such slicken sided interfaces cause adjacent and underlying beds in the roof to separate and fall after the coal is extracted, resulting in costly cleanups, production delays and losses, injuries, and even fatalities. Also, sandstone channel itself can cause stress distribution problems when it is in direct contact with the coal seam. In addition, the massive sandstone that will not cave behind the shield support may result in stress accumulation and disastrous accidents at longwall face. Due to extreme difficulty in measuring and/or evaluating the effects of sandstone channel On work face in the field, long wall panels usually do not extend near to channel body and under most of the cases stop prematurely once the existence of sandstone channel is determined. In this study, the effects of a large-size sandstone channel on longwall face stability in terms of shield loading, stress distribution, floor heaving, floor punching, and face closure were analyzed and discussed. 2. MINE CONDITION AND DESCRIPTION OF SANDSTONE CHANNEL Generalized geological condition of the IIIinois Coal Basin, where deposition of sandstone channel is typical, was employed in finite element modeling. A geologic column of coal measure strata is shown in Fig 1.