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Key and difficult problems are the arching mechanism and the evolution characteristics of the pressure arch in the surrounding rock after the tunnel excavation. Regarding a practical engineering as background, the definition of pressure arch of a highway tunnel was given and the boundary parameters of the pressure arch were determined by using the combination methods of theoretical analysis and numerical calculation. Considering the size of the highway tunnel excavation, the strength variation of the surrounding rock, the stress state of the highway tunnel, the geometry of the pressure arch and its mechanical evolution characteristics were revealed. Then, the engineering mechanical models were built through fitting the pressure arch centroid lines, and the mechanical stability of the pressure arch and the instability failure modes were also analyzed. The results provide a theoretical basis for the construction and reinforcing design of highway tunnels.

Pedestrian- and cyclist- involved crashes at intersections remain a major concern in China due to high ratio of fatal injuries and fatalities. This paper develops the random parameters negative binominal model to determine the relationship between potential contributory factors and crash frequency involving pedestrians and bicyclists at intersection locations and identify the significant risk factors, using 4,066 observations over the period 2008-2013 from Zhengzhou and Xi'an, China. The use of random parameters' model is utilized as a mean to accommodate possible unobserved heterogeneity across intersections, and a maximum likelihood method with Halton draws is proposed to estimate the maximum likelihood of random parameters. Additionally, marginal effects are applied to assess the impact of expected instantaneous change of each dependent variable on crash frequency while keeping all the other covariates constant. Among many potential factors, passenger countdown timer, passenger push button, number of left turn lanes, left turn traffic, ratio of major direction AADT to minor direction AADT and driver's disregarding 'give-way' sign behavior,... etc. have significant association with passenger crash frequency, but a less impact on bicyclist crashes. The findings of current study could provide an important insight into traffic safety improvement projects for passengers and bicyclists at both planning and operational levels.

Traffic Impact Assessment (TIA) for proposed developments often relies on trip rates obtained from historical studies. One of the most commonly used references for estimating trip rates for different proposed land uses is the Institute of Transportation Engineers' (ITE) trip generation manual. There are many issues related to the accuracy levels associated with using ITS trip generation rates within the U.S. and for sites in other countries. This study focused on developing trip generation rates for hospitals in the city of Amman, where twenty one hospitals were surveyed during average weekdays and two categories of data were collected for each hospital; various traffic volume counts and specific descriptive information about the hospital including its area, number of beds and number of available parking stalls. This study showed that trip generation models developed in the ITE trip generation manual will not produce accurate estimates that could be used for proposed hospital sites. Several methods were used to develop hospital trip generation models, including single variable regression, multivariate regression and MLP algorithms. The data analysis showed that the number of patient beds and the gross floor area were the main factors affecting the number of hospital vehicle trip generation.

Workers' road safety in organizations represents a major issue in countries like France, especially when considering the large number of vehicles used in displacements assigned by companies. Despite continuing efforts to reduce the number of crashes, every year thousands of workers found death in their workplaces and millions suffer occupational injuries and illnesses. The communication in organizations could play an important role to increase road safety. To better know its role, this study measured managers' and employees' perceptions about the communication's role in six antecedents' safety management and performance of road safety practice self-reported safety knowledge, safety motivation, safety compliance and safety participation, by conducting a survey using a questionnaire among 165 employees and 135 managers. The reliability and unidimensionality of all the items of scale used were found acceptable. Path analysis using AMOS-19 software showed that some of the safety management of road safety practices have effects associated with the safety performance determinants and components; namely, all the six antecedents' only safety training and safety promotion have effects related to safety motivation, and only safety commitment, safety communication and feedback have effects related to safety knowledge. Safety behavior compliance was found to be the key mediator in explaining these effects and relationships, and only safety feedback has effects related to safety participation. Safety feedback was identified as the most important safety management factor to road safety practices that predicts safety knowledge, safety motivation, safety compliance and safety participation. The results of this study will contribute to the related companies' ability to assess the road safety indicators and will also be a contribution to the future development of safety performance management for road safety practices in companies.

To analyze the temperature field of freeze-proof separate lining in cold-region tunnels, based on a tunnel on national highway number 307, the numerical model was established by the finite element software ANSYS, combined with the heat transfer theory using a cylindrical coordinate system. The change law of temperature field of the separate lining was investigated when the ventilation temperatures were -5 deg , -10 deg and -15 deg . The heat insulation effect of separate lining was also analyzed when the diameters of holes in the insulating layer were 5 mm, 10 mm and 15 mm, respectively. The results show that the temperature of lining and rock masses decreases gradually with the decrease of ventilation temperature and that the maximum temperature difference occurs in a closed air layer; considering that the temperature is still above 0 deg . When the ventilation temperature is -15 deg , the separate lining structure can protect the tunnel from freezing damage. The temperature field of the lining changes significantly if the diameters of holes in the insulating layer are large; the temperature of rock masses is -8.5 deg when the diameter is 15 mm, and the structure of the tunnel may suffer freezing damage. The tightness of the insulation layer has significant influence on the heat insulation effect of separate lining.

The study of the balance and stability of tunnels is a matter of great importance. Movements resulting from excavation work on face and surface level of the tunnel are yet hard to apprehend. Lately, various methods and techniques of tunnel reinforcement have emerged, aiming firstly at controlling the deformations and settlements and on the other hand at maintaining the stability of tunnelling. The purpose of this work is to study the influence of strengthening the tunnel advance core on the behavior of the surrounding massif by comparing two methods of reinforcement, one called umbrella arch method and the other ADECO-RS method; which consist of strengthening the tunnel face with fiber glass bolts. These two methods have been used during the excavation work for the tunnel \"T4\" of the east-west Algerian highway. Numerical simulation results using the finite element program \"Plaxis 3D Tunnel\" have helped to demonstrate the potential efficiency of the ADECO-RS method compared to the umbrella arch method.