Wilkinson A.,Public Transport Div. |
Haque A.,Monash University |
Kodikara J.,Monash University |
Adamson J.,Pressure Injection |
Journal of Geotechnical and Geoenvironmental Engineering | Year: 2010
Lime slurry pressure injection (LSPI) is a stabilization operation used in problematic soils by transportation industries with the aim of improving the geotechnical properties and bringing excessive maintenance costs to an acceptable standard. This paper presents detailed field and laboratory studies of a lime/fly ash stabilized site at Breeza, NSW, Australia. The mixing of slurry into the soil with depths was investigated by excavating a trench while the improvement of geotechnical properties was determined in detailed field and laboratory tests. Visual observations of the surfaces of an excavated trench showed slurry to be distributed within the shrinkage cracks in the desiccated upper soil horizon whereas slurry was conveyed through planes of hydraulic fracture in the soils at greater depths. Laboratory swell tests on the stabilized soils demonstrated a statistically significant reduction of the intrinsic swell properties in the upper horizon of highly plastic clayey soils by LSPI. A gain in soil strength was observed in cone penetrometer test soundings conducted in stabilized soils. Scanning electron microscope and x-ray diffraction studies proved the underlying physicochemical and cementitious reaction processes in stabilized soils. Aggregation of the soils was observed with the outward diffusion of calcium cations within proximity of slurry seams and resulted in a subdued shrink/swell propensity. © 2010 ASCE.
Fenical S.,Coast and Harbor Engineering Inc. |
Rice S.,SDR Maritime and Analytics PLLC |
Salcedo F.,Coast and Harbor Engineering Inc. |
Ports 2013: Success Through Diversification - Proceedings of the 13th Triennial International Conference | Year: 2013
Passing cruise ships in confined navigation channels and harbors generate significant hydrodynamic forces on berthed vessels and affect mooring systems and shoreside structures. Accurate prediction of these forces is essential for improvement of navigation safety and optimizing port operations. The Vessel Hydrodynamics Longwave Unsteady (VH-LU) modeling system, whose original development was described in Fenical et al. (2006), has been under continual development as part of a comprehensive hydrodynamic modeling system incorporating ambient hydrodynamic processes present in complex and realistic port settings. The modeling system has been previously validated using field hydrodynamics and laboratory hydrodynamics and forces on berthed vessels, including the presence of a quay wall reported by van Wijhe et al. (2008) as reported in Fenical et al. (2011). The present paper focuses on a recent large-scale application of the modeling system to Port Canaveral, FL, in support of the Canaveral Harbor, FL Integrated Section 203 Report (widening and deepening project) sponsored by the Canaveral Port Authority (CPA). The port experiences complex surge effects generated by a "parade" of several large cruise ships leaving the harbor in succession, in particular, on windy days when higher speeds are necessarily employed to control vessel position within the channel. The Naval Ordnance Test Unit (NOTU) requested the study, with the concurrence of the Cape Canaveral Air Force Station (CCAFS), to demonstrate that the recommended project and the present and foreseeable future ship traffic would not adversely impact current or future NOTU and CCAFS waterfront operations within the Trident and Middle Basins. In addition, CPA also requested analysis of potential changes in mooring conditions at commercial berths. The simulations included the "parade" of three cruise ships leaving the harbor in succession under complex speed, drift and track combinations and subsequent surge wave sloshing on a complete, harbor-wide basis. Results included hydrodynamics and forces on 10 berthed non-commercial ships (submarines, combatants, mission service vessels) and 10 different commercial ships (cruise ships, tankers, RoRos, containerships, bulk carriers). Results for existing port conditions were analyzed and determined to qualitatively represent the surge effects observed and reported by pilots and terminal staff. Results of the analyses indicate that the proposed harbor deepening and widening are likely to lessen the surge effects. The results collectively targeted the most cost-effective locations for any future harbor modifications to reduce these effects. In addition, the results were used to demonstrate that increasing the "parade" departure timing interval effectively reduces the impacts to berthed vessels. © 2013 American Society of Civil Engineers.
Nguyen V.V.,University of Technology, Sydney |
Dackermann U.,University of Technology, Sydney |
Li J.,University of Technology, Sydney |
Alamdari M.M.,University of Technology, Sydney |
And 3 more authors.
Electronic Journal of Structural Engineering | Year: 2015
This paper presents a vibration-based structural health monitoring (SHM) technique for the identification of damage in a concrete arch beam replica section of the Sydney Harbour Bridge. The proposed technique uses residual frequency response functions (FRFs) combined with principal component analysis (PCA) to form a damage specific feature (DSF) that is used as an input parameter to artificial neural networks (ANNs). Extensive laboratory testing and numerical modelling are undertaken to validate the method. In the proposed technique, FRFs are obtained by the standard modal testing and damage is identified using ANNs that innovatively map the DSF to the severity of damage (length of damage cut). The results of the experimental and numerical validation show that the proposed technique can successfully quantify damage induced to a concrete arch beam simulating a real life structural component of the Sydney Harbour Bridge.
Mustapha S.,American University of Beirut |
Hu Y.,Infrastructure |
Nguyen K.,Infrastructure |
Alamdari M.M.,Infrastructure |
And 5 more authors.
Electronic Journal of Structural Engineering | Year: 2015
A statistical pattern recognition technique was developed based on the time series analysis to detect cracking in steel reinforced concrete structures using vibration measurements. The technique has been developed for the Sydney Harbour Bridge. The measurements were collected from single and tri-axial accel-erometers, which were integrated into sensor nodes that were developed at the National ICT Australia. The approach is based on two staged Auto-Regressive (AR) and Auto-Regressive with exogenous inputs (ARX) prediction models. The variation between the residual errors obtained from the intact and damaged states were used to define a Damage Index (DI) capable of identifying physical changed which could be due to structural damage. The effect of the severity of damage on the deviation of the AR-ARX model from its in-tact state was also scrutinised. The results of the field trial and the laboratory testing demonstrated the ability of the approach in identifying the presence of cracking and handling large volumes of data in a very efficient manner.
Public Transport International | Year: 2011
The Bochum-Gelsenkirchen Tramway Company, (BOGESTRA), has adopted the Systematic Human Resources Management concept, focusing on long-term sustainability to meet the company's economic and social goals. The Systematic HR Management approach involves the comprehensive development of the organization and human resources in the medium and long term. The company focuses on the advancement of women, the adoption of an innovative approach to forms of work, and the development of managers and other employees. The company works to achieve a good balance of women and men in working and decision-making processes and want to deploy more female strengths such as communication, customer orientation, conflict resolution and social skills. The company is focusing on increasing in the percentage of employees directly involved in customer services, so as to offer better quality and service to its customers. The company is currently offering the Sport Therapy and Prevention (STEP) for trainees and 50plus program for employees over fifty years of age.