土木環境工学ジャーナル

A simple probability analysis failure criterion for cable bolts in underground excavation is described. The criterion was developed using static loading tests of mechanical anchors (38 tons, 18 mm diameter cable, 2 m length and six strands), and Finite Element Method. Three static loading tests were performed, thereafter, an underground excavation was simulated with several wedges wherein the effectiveness of the bolt was tested in varying spacing, while other parameters remaining constant. A simple probability criterion was therefore developed to bridge the gap on identifying effective bolt length and total effective length of the bolts within the excavation in varying strata control (change in angle of the strata and change in thickness of the strata). The criterion is suitable for predicting the effective bolt length, predicting the total effective bolts length within the excavation provided the orientation and thickness of strata in known and also suitable to classify the excavation as over/under supported. Two practical applications and examples of the criterion are described. These are firstly, identifying of and secondly, predicting the effective bolt length and total effective length of the bolts in strata with varying orientation and thickness in both hanging and side walls.

The problem identified by research is the effects of blast loading on RCC structures. A comprehensive parametric study was conducted on RCC structure using the 3-D element model. In the analysis and design methodologies structures are subjected to blast loads with the understanding of blast phenomena and the dynamic response of various structural elements. This gives an parametric overview of the effects of blast effects on structures. Here in this paper, we are dealing with the blast force and its impact on the RCC structures. The blast pressures i.e. reflected blast pressure and overpressure have been evaluated. From this values blast forces have been evaluated. The values coming after displacement shows that as the floor height increases, deflection caused due to blast effect decreases. The result also shows relevant bending moment, shear force, axial forces. Deflection, axial force values of blast forces for charge 1500 kg at standoff distance 30 m is greater. Hence it has been concluded.

Loads and working conditions of the cross-section of 36 m span crane beam can be analyzed by finite element method. Firstly, analysis of the stress and deformation is completed under the dangerous condition of crane beam based on the ANSYS software; secondly, found out the stress concentration and fatigue crack sensitive area of the bearing; finally, captured the position of fatigue crack. All these methods can provide strong basis for implementing effective monitoring to the state of the crane beam stress. Thus, ensure safe operation of equipment and improve equipment utilization rate in work

In this research the electrocoagulation method was implemented in order to study the treatment of the spent caustic effluent from an olefin plant. To optimize the process parameters, Taguchi method was used, and the optimal conditions were found for pH of 6, current density of 35 mA/cm2, and treatment time at 40 minutes. The experimental results show that the final efficiency in case of reducing the amount of COD is around 89% under optimum operating conditions and pH has the most significant impact on the process with contribution factor of 79.10%. According to results of XRD and XRF analysis, the sludge behavior is very similar to that of sodium sulfate that is important for its value chain. The study results showed that the electrocoagulation method could be used a complimentary facility to reduce the amount of COD of Spent Caustic from an Olefin Plant.

Fiber-reinforced polymer (FRP) bars have been commercially available in civil engineering in the last twenty years. Due to their mechanical and physical properties, the behavior of FRP reinforced concrete (RC) members is significantly different to that of traditional steel RC. This paper presents the results and discussion of a numerical study of the flexural behavior of simply supported glass fiber-reinforced polymer (GFRP) RC beams under short-term static loads. The numerical analysis was performed using the Finite Element Method (FEM). All calculations were carried out in the environment of the Abaqus. The main objective of this paper was to investigate the flexural behavior of GFRP RC members depending on the reinforcement ratio. The results of the numerical analysis were examined and compared with code formulations and with the results of experiments.