Abstract Highwall mining involves driving a series of parallel entries with web pillars in between. These entries are driven by using a continuous miner with attached conveying system to extract locked up coal behind the highwall slope when the open cut coal mine reaches its ultimate limit. These entries are driven unmanned, unventilated and unsupported. Therefore, a detailed knowledge of structural features ahead of operations is essential in assessing the stability of these entries. Highwall mining operations can greatly benefit from accurate structural mapping of rock mass defects. The stability of these entries can be suitably assessed for any major roof failure by adopting discrete fracture network based structural modelling to characterize and delineate the regions of possible major roof failures to prevent damage to the conveyor and burial of the expensive continuous miner. In this paper, a generalized framework is described based on photogrammetric survey, digital mapping and discrete fracture network based structural modelling to characterise such failures for an Indian highwall mining operation. A sensitivity analysis is undertaken to demonstrate the significance of structure persistence in the geotechnical assessment. Such analysis would provide more insight into designing highwall mining layouts and in predicting possible impending highwall failures, and indirectly facilitates reducing machine downtime for better management of highwall mining operations. 1. Introduction Highwall mining operations offer the opportunity to improve coal extraction rates significantly provided geotechnical risks are managed properly. These risks include slope failure as well as roof collapse within the highwall entries induced by local failure, potentially resulting in loss of the continuous miner and conveying system. The Guidelines for Open pit Design [1] presents detailed recommendations for the management of uncertainty and risk in open cut slope design and the work described in this paper takes place within this framework. In this paper, we describe a framework that uses photogrammetric survey, digital mapping and analysis, stochastic structural modelling for the stability analysis of structurally controlled failures at an end user site in India. This study uses data previously acquired at an Indian coal mine site [2]. 2. Site details

Abstract The "Etruscan coast", south of Leghorn (Tuscany, Italy) presents several small pretty beaches closed by cliffs, which are constituted by ophiolitic rock-mass. This paper defines the geostructural and geomechanical setting of this ophiolitic rock-mass and presents a stability analysis of cliffs overhanging the beaches. A regional preliminary analysis led to define the coastal segments that display a high potentiality for rock-fall. In these segments, by means of self-developed GIS tools, were defined the slope-sites which displayed a high kinematic possibility in generating rock-falls. For these sites, trajectories and distances of rock-falls were calculated and probabilistic impact and fall-down areas on the below beaches were defined. The result is a Hazard Zonation of these beaches, which allowed the identification of areas that, in the public interest, should be closed while protective interventions are put in place. 1. Introduction 1.1 The problem In summer time, the "Etruscan coast", south of Leghorn (Tuscany, Italy) along Tyrrhenian Sea, is a crowded touristic beach site. Long segments of coast present small pretty beaches closed by overhanging cliffs cut into an ophiolitic rock-mass. Due to their wild beauty these beaches are particularly researched by tourists, therefore they are often very crowded. These cliffs are almost sub-vertical, due to the strong marine erosion at their bottom, and they are as well highly weathered due to seawater spraying during sea-storms. These cliffs can represent a real hazard for touristic fruition of the beaches because of rock-fall risk endangering the bathers. The recently developed EU Research Project PERLA was set up to deal with this problem. In the frame of this project it was defined a regional (ISR) and a local (IS L ) index of potential instability (Bini et al. 2013). This preliminary approach allowed the definition of coast segments to be further investigated. This study analyses in detail one of these segments, right north of Castiglioncello village (Fig. 1).

ABSTRACT: Through the exploitation of mobile terrestrial lidar, rockfall hazard analysis workflows can be optimized to produce minimally biased, repeatable results. Typical rockfall hazard analysis inputs include two distinct but related sections of variables; they are geologically and geometrically controlled. Geological controlled inputs are kinematic stability (joint identification) and rock block shape and size distributions. Geometrically controlled inputs are outcrop shape and size, road, ditch and outcrop profile. All of this information can be extracted or calculated from lidar data, as are demonstrated in this paper. 1 INTRODUCTION Highways and railroads situated within mountainous terrains are often subject to the hazard of rockfalls. The task of assessing roadside rockmasses for potential hazards typically involves a visual investigation of the rockmass by an engineer or geologist. At that time numerous measurements associated with discontinuity orientations and spacing, block size and shape distributions, slope geometry, and ditch profile are taken or estimated. The measurements are typically tallied according to the employed hazard rating system and a hazard level is determined for the site. This methodology involves direct exposure of the engineer to the hazard; as well, it creates a biased record of the assessed slope based on the skill, knowledge and background of the engineer. Light Detection and Ranging based technologies have the capability to produce spatially accurate, high-resolution models of physical objects, known as point-clouds. Mobile terrestrial lidar equipment can collect roadside data along highways and rail lines at flow of traffic speed at the rate of hundreds of kilometers per day. The use of lidar data for geomechanical investigation is strongly contingent on data management protocols, processing workflows, and standardized feature extraction techniques. Unlike measurements made in the field, all measurements taken from the lidar data remain part of the data structure and can be reinvestigated at a later date.

ABSTRACT The Berg Bock Highway Tunnel represents the southernmost link of the "Thuringian tunnel chain" of the new freeway A71 located in the eastern part of Germany. It comprises two tubes each 2700 m in length. From north to south, it passes through the Suhl granite, the base sediments and the porphyrite of the New Red as well as the layers of the Middle Bunter. The two tunnel tubes were driven by the shotcrete method within appr. 10 months. With four tunnel faces, maximum performances totaling appr. 30 mid were attained. Additional, supplementary demands on the safety conception, resulting from the findings from and the analysis of fire accidents in tunnels in recent years, had to be fulfilled in the execution planning at short notice. The inner lining is largely constructed using non-reinforced concrete. Reinforcement is only installed in the portal zones, in tunnel sections in less stable rock and in areas with a special cross-section as for instance cross connections and niches. STRUCTURE In the course of the new freeway (Autobahn) A71 connecting Erfurt and Schweinfurt, the Berg Bock Freeway Tunnel located between the exit "Suhl North" and the intersection "Suhl" represents the southernmost link of the "Thuringian tunnel chain" (Kleffner 2000). Two tubes each 2700 m in length are constructed (Fig. I). Each tube comprises two lanes each 3.75 m wide and two emergency sidewalks. The excavated cross-section of the tunnel ranges between 80 and 120m 2 . From north to south, the Berg Bock Freeway Tunnel passes through the Suhl Granite, the base sediments of the New Red, the porphyrite of the New Red and the layers of the Middle Bunter (Fig. 2). SAFETY CONCEPTION The safety conception is based on the Standards for the Equipment and the Operation of Road Tunnels (Figure in full paper) (RABT 1994). This standard is currently being revised on the basis of analyses of fire accidents in tunnels in recent years. Additional, supplementary demands on the safety conception (BMV 2001) had to be fulfilled at short notice in the execution planning for the Berg Bock Freeway Tunnel. The safety conception comprises nine connection drifts between the tubes at a distance ≤300m (Fig. 3). The connection drifts are equipped with emergency call niches and fire protection locks. Three breakdown bays are furthermore situated in each tunnel tube with at a distance ≤600m. Three connection drifts close to the breakdown bays are passable for rescue vehicles. (Figure in full paper) HEADING AND SUPPORT Heading and support of the tunnel were carried out by the shotcrete method. With four headings, both tubes were driven starting from the portals (Erichsen & Bachsleitner 2001; Schmidtmann & Erichsen 2001). Heading in granite gruss In the area of the northern portal (Fig. 4), the granite is very strongly weathered and grussed. As a consequence of the extreme degree of weathering and the strong water inflow, the following protective tunneling measures were carried out: – preceding drainage borings

ABSTRACT Artificial freezing method is the main means of shaft sinking in unsteady thick alluvium of underground mine, and drilling and blasting method for frozen rock and soil is the valid means to improve the sinking speed. In order to guarantee construction security and improve the sinking speed, blasting vibration test is necessary. Topbox vibration monitor is used and measure points were fixed on the location biggish deflective freezing pipes in the on-site test. Based on the test wave and data analysis using the analysis software, the relationship between radial vibration velocity, vertical vibration velocity and equivalent charge, equivalent horizontal distance, elevation discrepancy are established respectively. According to the test result, it can guide the blasting operation safety. INTRODUCTION Until now, there are not relative criterions or standards, Which raise standardization to blasting vibration in the frozen region blasting engineering of the vertical shaft. In virtue of the restriction of the blasting engineering characteristic, it is very difficult to proce internal shaft blasting test, and often cause apparatus damage. Therefore, blasting vibration dynamic measurement analysis On vertical shaft is an important means to prosecute blasting test on shaft top. MEASUREMENT PRINCIPLES Vibration measurement system principle showed as Figure 1. Topbox vibration monitor which was manufactured by Chengdu TOP electron Technique (Figure in full paper) Company is adopted at on-site test. This apparatus is of small cubage, lightweight, high delicacy and high autoimmunization etc. This system avoided such work as lead layout, inspection and reclaiming, and eliminated the dependence of measure on alternating current, which made the test convenient, credibility, and data processing simple and exact. SENSOR SELECTION AND LAYOUT Rational selection and correct layout of the sensor ensure the test succeed; so the following problems must be advertised when test. Sensor type and frequency range selection Acceleration sensor, velocity sensor or displacement sensor may be selected in accordance with the objection of the investigation. Acceleration sensor and velocity sensor are used most frequently in engineering, and velocity sensor is often adopted in blasting vibration monitor of rock engineering and underground engineering. Based on the estimation of quake wave frequency that is produced by blasting, frequency range can be selected. Generally, the frequency range of the quake blasting is usually 30 ~ 300 Hz, and the range of velocity sensor which can be selected on market is usually I0 ~ 500 HZ, this sensor can satisfy the require approximately. Sensor demarcation Sensor is susceptive apparatus and it is easily damaged when used in the bad environment, so it should (Figure in full paper) be demarcated at least one time each year, and the biggish deflective linearity sensor must be prevented to be used. Sensor layout Two aspects should be adverted, one is sensor fixing, the other is sensor direction. In order to reflect the magnitude of the vibration strength factually, sensor must be fixed firmly on the surface of the measure points to guarantee that it will not shift from the ground.

ABSTRACT: Verification of the efficiency of operational and technical measures in a problem field of rockbursts, hydrogeology, engineering geology, and supports in long mine workings and impacts on surface and underground structures is performed on equivalent models in the laboratory for equivalent modelling. The laboratory is well equipped with Sophisticated modelling equipment and measuring devices and staffed with the highly experienced and qualified personnel. ABSTRACT: Dans le laboratoire des essais sur modèles reduits qui est equipe d'appareils de mesure et d'essais de haute qualite et où travaillent les specialistes qualifies pour ce genre de travail on effectue la verification de l'effectivite des me sures techniques et d'exploitation dans les domaines suivantes: des coups de roche, la hydrologie, la geologie d'ingenieur, le soutènement des longs chantiers de mine, des effets de l'exploitation aux objets dans les mines et sur la surface. ABSTRACT: Im Labor des aquivalenten Modellverfahrens, das sehr gut vom Gesichtspunkt der Methodikaus vorbereitet ist, ist mit einer sehr guten Meβtechnik einer guten Qualitat ausgestattet. Die Spezialisten dieses Labors sind fahig, alle Möglichkeiten der Methoden des aquivalenten Modellverfahrens auszunutzen. Es wird hier die Modellbeglaubigung der Wirkung von betriebstechnischen Sicherheitsmaβnahmenim Problembereich der Gebitgsschlage, Hydrogeologie, Ingenieurgeologie, Grubenausbauten der langen Grubenbauten und der Einfluesse des Kohlenabbausauf Oberflachen- und Grubenobjekte durchgefuehrt. 1 TECHNICAL PREREQUISITES QUALITATIVE SOLUTIONS The qualitative solution of geo-mechanical problems by methods of equivalent modelling requires the fulfillment of methodical and technical prerequisites. The laboratory should be staffed with the highly experienced specialists who are capable to apply the method of equivalent modelling. The modelling materials of a good quality are needed which enable an appropriate modelling of geological structures, including the quality of discontinuity planes and to cope with a lack of sufficient information about the rock mass. The modelling frames of a good quality are required, for some tasks the flat frames are sufficient but, however, in some case it is inevitable to use spatial frames, along with a reliable and sufficiently precise technique for sensing and recording process of stress and deformation changes, including the computer processing. 1.1 Methodical preparation The basic assumption of qualitative modelling is the application of good modelling materials which can simulate the deformation process within the complete extente of strain characteristics, and which correspond with their rheologic properties to simulated rocks. This problem has been extensively solved through a systematic research programme (31), and now similar materials for the simulation of elastic and plastic rocks and soils are available in the laboratory. No less important is the field of a precise modelling of geologic structures of the modelled area. In the opinion of the authors it is inevitable to model all planes of disconuities and moreover, to simulate objectively their quality which can be charaterized, for example, by the friction coefficient, and to simulate the tectonic, failure as well as (28, 30). The generally well recognized problem includes the inssufficient information about the simulated environment. This problem has been solved in the laboratory through the so called verification of the model, which is based on the selection of a suitable phenomenon which, according to our experience is always present and which can be observed in the model. This phenomenon can, be, for example, the subsidence or convergence of the selected long mine working. Provided that the phenomenon in the model corresponds qualitatively and quantitaveily to the phenomenon the modelled environment, we assume that the model simulates in an acceptable manner the situation being modelled; provided that this phenomenon occurs or does not occur in a different quality, we perform a modification by means of increasing or decreasing the pressure in order to simulate as close as possible the situation in situ.