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This study aims to assess the safety effect of the paved shoulder width of a 175-km six-lane rural highway in India. First, the applicability of the matched case-control (C-C) method in the case of highway segments with multiple crashes was assessed. Second, the safety effectiveness of the paved shoulder and other risk factors were evaluated using the matched C-C method. Three scenarios with different case definitions were developed using the matched C-C method and ordinal logistic regression. The study used 100-m segment-specific speed, volume, geometrics, roadside characteristics, and fatal crash data between 2016 and 2018. Developed scenario results suggested that the matched C-C method can assess crash risks on segments with multiple crashes by defining cases separately or considering the number of crashes as an ordinal variable. Results also suggested that the probability of observing crashes increases as paved shoulder width increases. However, the probability of observing multiple fatal crashes decreases for wide paved shoulder width increases. The safety effectiveness of paved shoulder width assessment showed that a wide paved shoulder had a higher risk of a fatal crash than a paved shoulder width of 1.0 to 1.5 m. The segments with unpaved shoulders were unsafe compared to segments without them. These results can be used to prepare guidelines by road-owning and construction agencies to adopt safe paved shoulder widths for six-lane and multilane highways in India. Results may also support the development of a new highway design policy concerning preferable safe paved shoulder width for multilane greenfield highways in India. [ABSTRACT FROM AUTHOR]

As Japan faces a super-aging society, the increasing number of elderly people who are bedridden due to fall fractures has become a major social issue. Hip protectors have, thus, been proposed to prevent femoral fractures in cases of tumbling or falling; however, they are not widely used because the tightness of the equipment and the hassle of wearing it. In recent years, flooring materials with high buffer performance have been attracting special attention in the prevention of bone fractures in cases of tumbling or falling. So far, however, the “floor hardness test,” which is an evaluation method for cephalopathy (concussion of the brain), is the only risk assessment method for injury risks caused by flooring materials, and no such evaluation method is available for femoral fracture risks. Therefore, we fabricated a test instrument (pendulum tester) that reproduces the load that the femur received at the point of falling on the floor and developed a mechanism to assess fracture risks with high accuracy on the basis of the measured load. The pendulum tester is characterized by the following features: (1) has an impactor simulating the shape of the femoral region (made using the femoral computed tomography image of the elderly as a reference) and (2) has a dummy skin reproducing the buffering performance of human soft tissue. On conducting fracture risk assessment of four types of commercially marketed flooring materials using the pendulum tester, we found that the merits and demerits of the safety vary greatly by comparing with the evaluation results of the floor hardness test. The above-mentioned results show that an appropriate flooring material evaluation method should be chosen depending on the lesion site and type of injury.

In order to comprehensively evaluate the working state and safety performance of the bridge plate rubber bearing (PRB), the basic principle and method of SVM in machine learning theory (Support Vector Machine) was introduced in this paper. Firstly, the performance indices (such as the average compression stress, tangent value of the shear angle and the rotation angle of the PRB) were analyzed and calculated through its finite element model considering the different working conditions (axial compression, shear deformation and the rotation deformation of the PRB). Subsequently, considering the relevant indices affecting the safety performance of the PRB, the Pearson Correlation Coefficients (PCC) were calculated by SVM method for assessing the internal correlation of the performance indices of the PRB for different cases, respectively. The threshold values of the influential factors for different cases considering the PCC and the weight coefficient were obtained for grading the working state of the PRB as five levels. Moreover, in order to verify the validity and suitability of the evaluation of the working state of the plate rubber bearing by the SVM method, three apparent indices for grading the performance level of the PRB such as the crack, the undistributed spalling deformation and the dislocation of the PRB were analyzed and compared with the qualitative descriptions and the quantitative values. Finally, the corresponding threshold values for grading the performance levels of the PRB working states were proposed. It was shown that the SVM based evaluation method for the PRB is feasible and convenient, especially for the bridges with real-time monitoring devices to get the response data of the PRB. [ABSTRACT FROM AUTHOR]

The loss-of-reactor-level (LORL) where the coolant circulation path is lost is one of the important accident types of loss-of-heat-removal-system (LOHRS) in loop-type sodium-cooled fast reactors (SFRs). Due to the non-negligible possibility obtained by probabilistic risk assessment (PRA), pipe failures and succeeding sodium leakage in two points both occurred in primary heat transport system (PHTS) was assumed in this study, unlike the conventional studies assuming single pipe failures. The sodium level in reactor vessel (RV) is affected by many elements such as leakage position, guard vessel volume, operational state of pumps, and countermeasures to maintain sodium level which are sodium pump-up into RV and siphon-breaking of the pipe between RV and pump. Thus, a calculation program was developed in this study to evaluate and discuss the effectiveness of the countermeasures and safety margins for the loss of coolant circulation path. In addition, the crack size was discussed and evaluated realistically, and t 2 (t : pipe thickness) was obtained for a sufficiently conservative value, instead of Dt/4 (D : pipe diameter) that was assumed in the conventional studies. Time interval between two leakages was also given by PRA, considering failure rates of the pipes and components. Representative sequences and leakage positions where the sodium level can decline below emergency sodium level (EsL) were chosen, and the sodium level transient in RV was calculated where the crack size of the second leakage was set t 2. The calculations were also conducted where the larger crack size, Dt/4, was set for both the first and second leakage, in order to investigate additional requirements to maintain the RV sodium level. The evaluation results clarified that the coolant circulation loop can be maintained even after the second leakage in PHTS, taking into account the effects by the countermeasures.

Abstract: SDG-HAZOP method was introduced into safety evaluation of emulsion explosives production line for the first time in order to conduct safety evaluation of emulsion explosives production process more effectively and to reduce accidents, Firstly, hazard factors in a typical production line of emulsion explosives were identified after analyzing the whole process. Then the key variables and relationship equations were listed based on evaluation unit division. SDG-HAZOP qualitative model was developed, by which automatic reasoning and analysis was conducted. The result could express almost all dangerous factors and adverse consequence, and can reveal the path of danger propagation. Finally, a safety evaluation system for emulsion explosives factories was built, which is practically significant to guide safety production. [Copyright &y& Elsevier]

Various damage models were proposed to quantify the life of TBCs subjected to elevated thermal exposure loads, which are of great engineering significance, but they can not achieve satisfactory life prediction accuracy in the medium-long life stages, and also can not distinguish the additional damage caused by thermal cycle. In this paper, based on the 3D-DIC technique, the spalling strain of the coating system under different thermal treatments was obtained, and it can be used as a parameter to quantify the damage of the coatings. Based on the above work, a damage model was developed, which can not only model the damage evolution of coatings but also describe the additional damage introduced by thermal cyclic behavior. Based on the proposed damage model, this paper discussed the life prediction accuracy of coatings in the medium-long life stages and compared the weight method, thickness method and the method proposed in this paper. The results show that the proposed method based on the spalling strain as the damage parameter is of great significance to improve the life prediction accuracy of coatings in the medium-long life stages. Image 1 • 3D DIC technique was introduced to quantify the properties of coatings. • A novel model was developed to characterize the damage of coatings. • Spalling cycles vs. thermal dwell time was successfully modeled. • Performance of various methods was estimated in the medium-long life stages. [ABSTRACT FROM AUTHOR]