Safety Performance in Industrial Construction: A Case Study

This paper presents a case study of a safety training program developed by an international leading construction firm. The study was prompted by the continuing challenge of work- related accidents in the construction industry. Even with the measurable safety improvements in the last several decades, the construction industry still exhibits high rate of occupational fatal injuries compared to other industries. A linear regression model was developed using Microsoft Excel to determine the level of impact of the number of training hours on the resulting safety performance. The analysis confirmed that the number of training hours had a strong impact on reducing safety incidents. The coefficient of determination (R2) demonstrated that the number of training hours accounted for 81% of the variance in the incidents rate. The study results should assist in quantifying the cost-benefits of implementing safety programs, and in justifying the mandating of a certain number of training hours

dSDiVN: a distributed Software-Defined Networking architecture for Infrastructure-less Vehicular Networks

In the last few years, the emerging network architecture paradigm of Software-Defined Networking (SDN), has become one of the most important technology to manage large scale networks such as Vehicular Ad-hoc Networks (VANETs). Recently, several works have shown interest in the use of SDN paradigm in VANETs. SDN brings flexibility, scalability and management facility to current VANETs. However, almost all of proposed Software-Defined VANET (SDVN) architectures are infrastructure-based. This paper will focus on how to enable SDN in infrastructure-less vehicular environments. For this aim, we propose a novel distributed SDN-based architecture for uncovered infrastructure-less vehicular scenarios. It is a scalable cluster-based architecture with distributed mobile controllers and a reliable fall back recovery mechanism based on self-organized clustering and failure anticipation.Comment: 12 pages, 5 figures, accepted in I4CS201

A Model for Predicting Construction Worker Fatigue

Fatigue impairs workers’ judgment, reduces their productivity, and jeopardizes their safety. The paper presents a tool to predict workers’ fatiguebased on their vital signs. An experimental study was conducted in whichthe heart rate and sleep quality for three individuals were monitored usingfitness trackers (wearable sensors). The data collected were used to developtwo models based on regression analysis and Artificial Neural Networks(ANN), to predict their fatigue level. A Borg’s scale was used to estimatethe Rating of Perceived Exertion (RPE) of the participants. The two modelswere able to satisfactorily predict the RPE (workers fatigue level) with anaverage validity of 75% and 80% for the regression ANN models, respectively. The developed models can provide project managers and superintendents with early warning to avoid potential worker overexertion, injuries,and fatalities

Optimum Dispersion Parameters of Carbon Nanotubes: Concrete Strength by Response Surface Methodologies

"This paper implements Response Surface Methodologies (RSM) techniques to illustrate the maximum carbon nanotubes (CNTs)-concrete mechanical properties responses to the length, weight fraction and treatment variables. Mixes with different CNTs’ content were prepared and tested for flexure, compression and tension. RSM analysis showed that the highest effect on the strengths was due to the CNTs’ content variable. The analysis showed that a weight fraction of 0.3 wt.% of non-treated CNTs is required to achieve the maximum flexural, compressive and tensile strengths in a batch as per the predicted model. RSM analysis also showed that maximum flexural strength will be obtained by using 0.2 wt. % non-treated long CNTs, 0.25 wt. % non-treated short CNTs and 0.03 wt. % treated long CNTs, respectively.

Enhanced relay selection decision for cooperative communication in energy constrained networks

International audienceMost of current works related to relay selection algorithms in cooperative communications use the Channel State Information (CSI) to decide whether to use one or another neighbor as a relay. Therefore in wireless sensor networks where the energy is the major constraint such algorithms may lead to quick battery drain of the nodes having the best links. In this paper we propose to enhance the relay selection decision process by taking into account the energy metric in addition to CSI. The results show that we can redistribute the consumed energy when we use the energy as a relay selection metric

COSMIC: A Cooperative MAC Protocol for WSN with Minimal Control Messages

International audienceOver the last decade cooperative communication in wireless sensor networks (WSN) received much attention. A lot of works have been done to propose a MAC layer that supports cooperative relaying. The majority of these works tried to adapt the IEEE 802.11 MAC protocol to sensor networks. The adapted protocols use a lot of overhead (such as the use of RTS/CTS as well as other messages used to allow cooperation) that consumes energy. In this paper we propose a CSMA/CA based MAC protocol that supports cooperative communication with a minimum overhead: COSMIC (A Cooperative MAC Protocol for WSN with Minimal Control Messages). Relay selection in this new protocol is performed using both the channel state information (CSI) and the remaining energy. Simulation results show that COSMIC is able to increase the network lifetime by 25%

Using Behavioral Based Safety to Enhance Safety Performance

 Safety in the construction industry has progressed exponentially in the last century. The development of the Occupational Safety and Health Administration (OSHA) may be seen as a major milestone for work place safety. However, the first stages of OSHA were reactive. In the early 2000‘s, companies placed aggressive focus on the application of proactive measures in preventing incidents rather than simply reacting. Risk Assessments, Constructability Reviews, and Hazard Identifications were few of the best practices implemented in this time period. Experts now believe the implementation of a Behavioral Based Safety Program (BBS) is the next revolutionary technique to help decrease injury rates further. Several studies were conducted which exhibit a correlation between effective BBS implementation and OSHA classified recordable injury rates. However, there are no previous studies identifying correlation between BBS implementation versus Near Misses, and BBS implementation versus OSHA classified First Aid Cases. This paper helps identify whether BBS implementation on a typical Petrochemical/refinery construction project impacts the number of Near Misses and First Aid Cases. BBS was implemented on 14 different construction projects within Technip, collecting all BBS and incident data, and applying different analysis techniques to identify existing trends between BBS observations/First Aids Cases/Near Misses.  It helps identify whether BBS improves the safety performance on a job site by identifying its impact on injuries, in addition to Near Miss reporting. The paper will assist similar companies with evaluating whether the implementation of a BBS program yields favorable results to the safe performance of their projects

Resource-Constrained Construction Scheduling Using Agent Based Modeling Technique

 This paper presents the use of Agent Based Modeling (ABM) technique as a tool for optimum resource constrained scheduling.  The model added two features to the standard resource scheduling applications. It allowed activity interruptions when necessary and the impact of the quality of the predecessors on the successors' duration. An illustrative example is offered to demonstrate the performance of the proposed model. ABM technique was confirmed to be a valid approach for seeking alternative solutions in resource constrained schedules. The model proved advantageous to resource-constrained schedules. It illustrated additional flexibility to the standard techniques for resource-constrained problems. The model was proven successful in minimizing the project duration under preset priority rules

Self-compacting Backfills using Fly Ash and Dredged Marine Sediments for Public Work Applications

Sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. In France, the maintenance of the 6500-kilometer long coastline would require the extraction of about 50 million m3 of marine sediments every year. For several years, these sediments were considered waste. However, they are increasingly being acknowledged as a resource in need of management. Several research studies were conducted to find valorization ways that satisfy technical and regulatory requirements. These sediments present interesting heterogeneous physicochemical, mineralogical, and geotechnical characteristics. However, they may contain contamination, which could limit their uses. This paper deals with the possibility of producing self-compacting backfills using dredged marine sediments, fly-ash, and hydraulic binders for public work applications. The impact of dredged sediments on the composition of self-compacting backfills was studied. Moreover, the impact of fly ash and binder type and percentage on the backfill behavior and mechanical properties was discussed

Marine Dredging Sediments Valorization in Self-Compacting Concretes

Rock and eroded soil are transported by wind, tide, and human action (development works), and deposited as sediment in ports, estuaries, and rivers. The sediment accumulation at the bottom of ports disrupts maritime activities and disturbs the physicochemical balance of water bodies. As a result, dredging is necessary to reduce sediment deposits and restore the natural environment for proper port functioning. At the national level, the maintenance of the 6,500-kilometer French coastline would require the extraction of about fifty million cubic meters of marine sediment every year. These dredged sediments have been used in civil engineering applications for about ten years, in order to reduce their economic and environmental impact. The proposed study addresses the potential use of sediments to produce accropode blocks for maritime public works applications. It consists in developing concrete mixtures using dredged marine sediment treated to protect against erosion. A study of material characterization, optimization of the composition of the concrete formulation, as well as a determination of the mechanical, physical and durability properties of the concrete were necessary to validate the technical feasibility of this new solution. Around 700 small accropode blocks were then prepared to better analyze the structure stability against swell effects. The obtained results show that the sediments could not produce Self Compacting Concrete (SCC). However, sediment treatment with 6% by weight of cement has enabled the production of SCC. It is worth noting that the use of superplasticizer was essential to ensure concrete workability. Increasing the cement percentage has also improved the composite workability. Finally, a concrete compressive strength greater than 40 MPa has been achieved when using 300 kg/m3 of treated sediments