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By Philippe Caudal

This paper presents a case study in which a slope failure was observed on the west wall of the LAB Chrysotile mine in the vicinity of the main ramp in January 2010. Airborne LiDAR results were used to evaluate slope geometry before and after the failure occurred. Back analysis of the failure was performed to assess rock mass properties at the slope scale using various numerical techniques: limit equilibrium, finite elements and fracture networks. The various approaches correlated well with field observations.

Aug 1, 2013

By C Kumar

Scaffolds are temporary structures built to facilitate construction activities on site. A considerable amount of resources are allocated to scaffolding on industrial projects. Variability in geometrical features and space accessibility of structures on industrial projects, in addition to involvement of different trades that share the use of scaffolds, requires an extensive understanding of scaffolding requirements. Hence, it?s important to plan and estimate scaffolding man-hour requirements for the different construction areas on an industrial site. Contributing factors involved in such estimates include the list of trades that work in a construction area, trade working hours, volume of work, geometry of equipment erected, etc. A simulation template for predicting scaffold erection man-hour values for individual construction areas in an industrial project was developed in Simphony 4.0. The template is based on mapping the geometry of equipment and other factors to man-hours of scaffold work. The template facilitates the use of distributions as inputs and produces a range estimate of scaffold man-hours. The mapping is based on a linear regression model derived from existing project data from PCL Industrial Management Inc. The template is being further developed to incorporate the ability to predict scaffold erection schedule and material requirements based on construction work areas or equipment lists of an industrial construction project.

Aug 1, 2013

By Niklas Willemsen

Introduction to SVCs ? SVC = Static var Compensator ? Dynamic step-less control of reactive power without switching of passive components: ? Voltage control/stabilization ? Harmonics- and flicker mitigation ? Dip mitigation ? Main components: ? TCR (Thyristor Controlled Reactor) ? Tuned harmonic filters ? Control- and cooling systems ? Typical applications: ? Mine hoists ? Large mining complexes ? EAF, SAF, rolling mills, wind/solar farms etc..

Aug 1, 2013

By R. S. Adhikari

The changes in defects patterns or in element condition index during visual inspection of bridges are primary concerns for inspectors. This paper presents a new approach for change detection of defects in bridges by identifying changes in texture patterns through spectral analysis of digital images. The commonly used method for change detection is image differentiation. This subtraction method requires images to be of same size, scale, and rotation. However, no two images are same in real practices. Thus, image registration is required to align images and to produce change maps. This process is tedious and it is difficult often to achieve a good registered image. But, the change detection task can be readily modeled in frequency domain for texture patterns discrimination and also for quantifying their properties. This paper proposes a novel approach for change detection by transforming digital images into Fourier spectrum. In new coordinate system, 1-D signature functions can be drawn which facilitates easy comparison of textures in different directions. The proposed methodology provides useful tools for comparison of inspection history graphically and quantitatively. In practice, expensive sensors are used to detect subtle change in defect patterns. The proposed method can be used to detect any subtle change in defect patterns using digital images at much lower cost.

Aug 1, 2013

By Ali Montaser

This paper presents an experimental study conducted to facilitate the use of RFID on construction job sites. The study focuses on deployment settings to provide data acquisition with higher accuracy for indoor location sensing. It provides extension to the state-of-the-art in this field as it addresses the impact of metal media proximity to RFID tags, the reasonable duration for data capturing, number of RFID tags employed and the distance between them. Low cost passive RFID tags were used in the experiments where each tag is used as a reference point with a known location. Five hundred and forty (514) experiments were conducted in lab environment using a 3m by 3m test bed that is dynamically rearranged to generate 15 test beds and a total of 67713 data sets were collected and analyzed. The collected data were captured from nine locations for each test bed at four time intervals. Received Signal Strength Indicator (RSSI) was used as the main attribute for signal measurement to process the captured data. Results of the data analysis performed are studied under four main categories: duration, number of tags, locations of tags and metal interference. The best duration was found to be the 15 second in the test bed with the least number of tags; as the short amount of time to capture data did not allow creation of a lot of interference among the emitted signals. Within each test bed, errors occurred most at points where the received signals were not well distributed in a 360 degree vicinity of the data capturing point. It means that the center point of each test bed resulted in lowest errors and the points located on the extremities led to the highest errors. Finally, metal objects were found to have major impact on the accuracy of the captured data; to the level where reliable values for errors could not be calculated in the test beds attached to metal objects. In summary, the results of the experimental study and related findings are expected to provide guidelines to the users of RFID technology for localization in building construction.

Aug 1, 2013

By C. Mawdsley

The Tata Steel mill at Skinningrove in the North East of England produces top hat sections for mineshaft guides in sizes 102 and 150 mm. The top hat section is the technically preferred shaft guide choice for modern deep mine shafts. This paper explores the relative service performance of top hat and square hollow section guides in service. Comparative corrosion performance is reviewed and the paper describes work commissioned by Tata Steel (as Corus) undertaken by Aker Kvaerner Engineering to evaluate relative winding speeds, relative loads and fatigue life in service. The experience of supply to UK Potash mining is discussed and the future view of high capacity hoisting and larger section size market need and availability is assessed.

Aug 1, 2013

By Lopatka. M. J.

This paper presents the results of 3 tons skid steer 6x6 wheel robot drive system field tests. The aim of the investigation was verification of assumed data for drivetrain diesain and forces identification in the drivetrain system during maneuvering and crossing obstacles. Robot has hydraulics drive system with motors in the wheels and hydraulic suspension system. The neded drive torque on wheels was determined by pressure measurnig on motors.

Aug 1, 2013

By Andre L. Du Preez

Global mine hoisting regulations require safety fall arrest systems to be installed on vertical conveyance systems capable of safely decelerating and supporting a fully loaded conveyance in the event of a rope severance. Most current arresting systems are incapable of producing controlled safe deceleration rates. Although safety ?dogs? achieve marginally acceptable results on wooden guides, difficulties arise in achieving safe deceleration performance requirement where safety arrest systems operate on steel shaft guides. Previously, arresting systems capable of operating with steel guides have been incapable of producing controlled deceleration rates during the arresting of free-falling conveyances. Most are ?instanton? systems, whereby an occupant inside a conveyance being arrested would be subjected to unacceptably high deceleration forces. This paper briefly highlights the background to the selection process of Rio Tinto?s Technical Staff of a suitable Mine Conveyance Safety Fall Arrest System for #1 Shaft at Rio Tinto Oyu Tolgoi Mine, Mongolia. It also describes the Drop Test and Free Fall Test procedure and the results leading to the acceptance of the Horne Group Levelok® Emergency Braking Technology for the Oyu Tolgoi #1 Shaft in Mongolia. The paper highlights Rio Tinto?s primary objective for the selection of this advanced technology on their primary production shaft cage system as an emergency safety catch braking system combined as an advance hydraulic chairing system. It describes the design and operational parameters and the 'Fail to Safe' interfacing with current automated mine hoist systems.

Aug 1, 2013

By Changyoon Kim

Technological advances in mobile systems, such as smartphones and tablet computers, provide engineers with new opportunities to enhance the current facility management processes. Equipped with powerful system processors, touch screens, and wireless communication capabilities, mobile systems enable the experience of omnipresence of facility information. Building information modeling (BIM) also enables improvements in facility management. With an advanced data structure and visualization capacity, BIM can be used in numerous applications for facility management. This study aims to incorporate the strength of mobile systems and BIM in facility management. The proposed system, which utilizes smartphone technology, allows engineers to conduct facility management functions, such as maintenance planning, inspection, and assessment, irrespective of a user?s location. The integration of building information modeling in a system provides detailed visual information of the building components. A case study was conducted to verify the applicability of the mobile system in terms of the hardware functions, system design, and user interface. This proposed system, with its study results, provides a guideline as to how mobile systems can be effectively integrated with BIM for improved management of facility information.

Aug 1, 2013

By R. Roufail

Mineral exploration is in a race to employ drilling technology that can perform the exploration and drilling investigation in a fast and inexpensive manner. After an extensive study of the available drilling technologies in the market, coiled tubing was chosen as a tool to be employed for mineral exploration due to its flexible mobility and ease of operation with a minimum number of personnel. Since coiled tubing technology is primarily used in the oil and gas industry, it was important to re-design the coiled tube rig to drill hard rocks in a fast and feasible manner. The main requirements were to drill the smallest feasible hole diameter and go as deep in the ground as possible, in the shortest reasonable time. The drilled rock particles, cuttings, are to be collected and analysed at the surface for their metal mineral contents. The process also needs to be repeated multiple times at different locations for mapping, without the need to change the tube on the rig due to failure or potential failure. The focus of the new designed coiled tube, for drilling and mineral exploration, is three fold. First is to increase the rate of penetration in drilling by designing a small high speed turbo motor. Second is to determine the controlling parameters of cuttings transport to effectively lift the cuttings to the surface for analysis and third is to minimize the overall weight of the rig for manoeuvring and prolong the life span of the coiled tube string. In this paper, a small downhole turbo motor, 5cm outer diameter, is designed to achieve a rotation speed of up to 10,000 rpm to fit on a small bit, coiled tube drilling assembly. The motor design utilised multiple finite volume and finite element analysis softwares for fluid flow study and fluid structural interaction analysis. The paper is also introducing the concept of a flow slurry loop that is designed to lift the cutting particles to the surface for mineralisation analysis. The controlling parameters of the cuttings transportation are the particle?s physical properties such as size, density, concentration and shape, as well as the rheological properties of the carrying fluid, drilled hole angle, as well as the fluid flow rate and flow dynamics within the annulus gap between the coiled tube and drilled hole. Such parameters are addressed via experimental work as well as numerical analysis. The paper is also presenting the selection and testing procedure of the material type for the coiled tube string. The tube needs to be light in weight for overall rig weight and its transportability. The tube is also required to drill several dozens of investigation holes before failing due to fatigue. A fatigue bending machine is designed to test the endurance limit of candidate materials for coiled tube strings and a performance index methodology is followed for material selection of the optimum material. The coiled tube rig is designed to be light in weight for transportation and relocation. It is also required to speed the drilling operation with the minimum footprint and reclaim the drilled rock particles for mineral composition analysis at the surface.

Aug 1, 2013

By A. Grimod

The European Guideline ETAG 027 - 2008 (?Guideline for European Technical Approval of Falling Rock Protection Kits?) defines the procedures to test rock fall barriers. Nowadays, this guideline is essentially the only test and construction framework utilized by manufacturers and it is also starting to enter in the mentality of designer who can clearly specify the performances of rockfall barriers. ETAG 27 (and the related European Technical Approval and the CE marking) represents a milestone for the rockfall barrier market, because it gives the possibility to compare the performances of different fences and it ensures the quality of the certified product. For these reasons ETAG 27 presently constitutes the base for tenders all around the world. Although rockfall barriers are in common use, designers and consultants do not have a clear overview of the real performances and the technological limits of these structures. The first problem can be solved using ETAG 27 criteria, which allow designing rockfall barriers at ultimate and serviceability limit state. Even though ETAG 27 uses crash tests performed with the Service Energy Level (SEL) and Maximum Energy Level (MEL), design with these concepts is not obvious or in common acceptance. Some preliminary questions must be solved. When can these energy levels be correctly applied? In the case of rockfall simulations, what probabilistic approach must be used for the evaluation of the barrier? Unfortunately ETAG 27 does not give any information or tests relating to the technological limits of the fences. Therefore some important questions arise. How do the site specific aspects of installation affect the barrier performance? What is the behaviour of the barriers under extreme conditions? And finally, the main question lies in the background: what is the functional reliability of ETAG 27? All of the above questions require comprehensive answers, which is consistent with the experience of designers, installers and producers. Officine Maccaferri S.p.A., with its 130 year experience in the field of rockfall protection, collected a large number of case histories with barriers impacted by single or multiple blocks, debris flows, and snow avalanches. Throughout these case histories and in accordance with a recent Italian standard code, it has been possible to implement a reasonable design approach that considers the efficiency of the barrier, the uncertainties of the input data, and the fore

Aug 1, 2013

By Nehad Elsafty

It is always necessary to expand existing buildings, so that they could meet the growing societal needs. Compared with demolishing them and then constructing new ones, the expansion of existing buildings could not only reduce project cost, but also save the use of energy and raw materials in projects. Therefore, it is widely adopted in most under-developed countries. However, the expansion of existing buildings is not an easy task. It has been involved with a lot of issues in defining the scope of work, planning landscape, managing construction activities, etc. This paper investigates the potential challenges in expanding existing buildings. The project of expanding the Al-Agoza Hospital, one of the biggest and oldest hospitals in Cairo, Egypt, is selected as a case study. In the case study, the project documents have been carefully reviewed. The project engineers and the health-care professionals working in the hospital have been interviewed. This way, the point of views from the owner, the architect/engineer, and the contractor have been taken into account. Several lessons are learned through the discussion with these people. The results from this paper are expected to provide pieces of useful advice and suggestion for the expansion of existing buildings in the future.

Aug 1, 2013

By Silvio E. Kruger

Real time measurement of wear and corrosion provides crucial information needed to determine an optimal schedule for corrective maintenance and is a powerful tool to maximise equipment availability and reliability. It also leads to savings from optimized spare parts handling and helps to avoid costs of accidents and their negative impact on safety and the environment. This paper presents the technology of ?painted-on? ultrasonic transducers that can be integrated to structures and accurately measure the remaining thickness and therefore determine wear or corrosion losses. These transducers have a small footprint, a performance comparable to other commercially available ultrasonic transducers and can sustain temperatures as high as 400ºC. The application of this technology to mining equipments and its potential benefits are discussed.

Aug 1, 2013

By S. Aram

Product Lifecycle Management (PLM) solutions have been serving as the basis for collaborative product definition, manufacturing, and service management in many industries. They capture and provide access to product and process information and preserve integrity of information throughout the lifecycle of a product. Efficient growth in the role of Building Information Modeling (BIM) can benefit vastly from unifying solutions to acquire, manage and make use of information and processes from various project and enterprise level systems, selectively adapting functionality from PLM systems. However, there are important differences between PLM?s target industries and the Architecture, Engineering, and Construction (AEC) industry characteristics that require modification and tailoring of some aspects of current PLM technology. In this study we examine the fundamental PLM functionalities that create synergy with the BIM-enabled AEC industry. We propose a conceptual model for the information flow and integration between BIM and PLM systems. Finally, we explore the differences between the AEC industry and traditional scope of service for PLM solutions.

Aug 1, 2013

By Magdy Ibrahim

This paper presents experimental design and development of a low-cost remote sensing hardware designed to support automated site data acquisition for near real-time progress reporting of construction operations. The developed hardware utilizes open source microcontroller equipped with multiple sensors that include 3D accelerometer, GPS, Data logger and Bluetooth. The use of open source microcontroller makes the developed design cost effective; freeing it from the need for costly license fees. Its platform configuration is flexible; enabling the addition of temperature, weight and other sensors, Wi-Fi and Xbee capabilities to suit individual field applications. Pilot tests have been carried out in laboratory and outdoor environments. The results prove effectiveness and robustness of the developed configuration. The paper provides description of the individual components used in the development of this prototype hardware. It also describes the technical characteristics, capabilities and limitations of the developed hardware. The findings of comparison with alternative technologies used for outdoor tracking of construction operations are presented. The comparison is carried out with respect to range, cost and suitability for outdoor environment. The developed hardware is expected to support a wide range of applications including tracking of earthmoving operations, highway construction and onsite resources. As well, it is expected to enhance safety on construction jobsites.

Aug 1, 2013

By D. Holz

In this work we present a novel level set-based model for the real-time simulation of soil deformations. A level set defined by a signed distance function and sampled in a regular 3D grid represents and tracks the soil volume under deformation. Moving away from classical 2.5D heightfield representations of soil to a full 3D volume representation allows for improved tracking of cutting tool operations and the simulation of near-vertical or vertical soil faces. The proposed level set representation furthermore provides a versatile mathematical platform for modeling additional effects such as soil slip, and does not suffer from the sampling limitations of commonly used heightfields. Cutting forces applied to the tool are simulated via a formulation based on the Fundamental Equation of Earthmoving, modified to support inclined soil surfaces and transient states of tool motion. Discretisation of this 2D cutting force model with respect to the tool surface allows capturing the effects of irregular 3D terrain shapes on blades and buckets. The surcharge created during cutting operations is tracked in the form of particles and included in the soil failure force computation. We make use of an adaptive, hybrid level set-based and particle-based soil deformation scheme, which allows the soil deformation to be simulated in real-time.

Aug 1, 2013

By Hao Zhang

Site inspection is an important component of safety management system. In current practices, the inspectors evaluate the safety condition on a construction site with the assistance of a standardised checklist. However, the checklist emphasizes on evaluating the implementation of safety management system, but provides limited task-specific check items for assessing whether the individual construction tasks are conducted under safe condition and in a safe manner. To address this issue, the research presented in this paper aims to provide safety practitioners with comprehensive and taskspecific safety information to promote effective risk identification and facilitate strategic risk control during site inspection. Specifically, this research first builds a project-specific safety information database, which stores potential risks and control measures for each construction task. The research team then develops a mobile decision support tool to retrieve information from the database and support safer decision-making on site. The tool supports users in two ways: one is to provide daily risk checklists and risk control strategies to guide step-by-step inspection alongside the project schedule; the other is to let users input any safety-related keywords during the safety inspection process and the tool returns relevant safety information by applying text mining algorithms. It is ongoing research. This paper presents an overall research framework and discusses the progress in developing safety database and data retrieval concepts. The outcome of the project will help enhance safety management practices and reduce possible risky working conditions on a construction site.

Aug 1, 2013

By K. Iturralde

The topic of this article is the automation and robotization in refurbishment processes of industrial buildings. The need to mold these production spaces is quite universal. Particularly in the regions with a high industrial development and with a lack of buildable land, there is a need to convert this kind of spaces into an improved production system. The latest developments can be a useful tool for achieving a more efficient way of reforming this type of construction. On the one hand we have the digital or computerized 3D Laser Scanning (Computer Aided Measurement) that allows an accurate 3D modeling of the entire building. On the other hand, the project management using BIM (Building Information Modeling) could provide an easy design of each of the elements of the refurbishment. Finally, through the production of construction elements using robotics as jig or for CNC (Computer Numerical Control) we achieve a neat production of each element. How can be all those technologies applied in the refurbishment or expansion of industrial buildings? The research takes a first approach and analyzes industrial buildings that can be called generic or not specialized. To narrow the field of refurbishment, three major factors are defined. The first is to minimize the bill of the energy consumption of the buildings. This could be done either insulating the envelope, reducing the waste-volume to be conditioned climatically or creating facilities for energy production. The second is that the refurbishment or expansion of industrial buildings should try not to interfere on the production process that takes place in the building. In other words, the assembly of the elements in the construction site should be quick and easy, causing the least of disturbance at the workplace. Finally, the research makes an approach towards a robot integrated industrial or productive building .

Aug 1, 2013

By A. A. Goss

We investigate the relationship between corporate financial performance (CFP) and environmental and social performance (CSP) in a sample (n=165) of large, publicly traded U.S. mining and oil and gas firms. Using optimally scaled principal components analysis to generate aggregate measures of CSP strengths and concerns, we find higher concerns are related to higher volatility of unexpected earnings and discount rates. Furthermore, these earnings shocks are more likely to be negative as concerns increase. Decomposing this relationship shows that negative environmental performance dominates proactive environmental management as a driver of unexpected earnings, but proactive community efforts increase the magnitude of earnings shocks. We document some evidence of the strategic use of CSR, with those firms that have greater risk investing more proactively in CSR.

Aug 1, 2013

By Zou Lisheng

The culture of safety is very important to coal mining production. About 90% of mine accidents are caused by human error. This paper analyzes the status of China?s coal mining accidents, and accident cause. This paper explains the concept of safety culture, the value of safety culture, as well as the relationships between safety culture and safety behavior, and between safety culture and science and technology. The paper proposes the model of safety culture and the ways to enhance safety culture of coal enterprises. Safety culture and safety production is closely related and are significant to the improvement of mine safety situation in China.

Aug 1, 2013