In order to select the barrier level in the roadside safety design, the models of single unit truck collisions with level 3 to level 6 concrete barriers was established by adopting explicit finite element software LS-DYNA 3D, the impact speed was between 40 km/h and 80 km/h. Using finite element model of modified vehicle verified by full-scale impact test to improve creditability of the simulation model. The relations between impact speed, level of concrete barriers and the amount of vehicle overhang beyond the barrier was studied, the effectiveness of concrete barriers shielding roadside obstacles was quantitatively evaluated, and the minimum safe distance from the traffic side of barriers to roadside obstacles was obtained, the relationship between the Chinese specification method and the 50 ms mean lateral impact force in the calculation of barrier impact force is compared; The equation of important roadside obstacle impact force was developed and evaluated, and the design value of important roadside obstacle impact force is revised. The results indicate that when the barrier level is level 3 to 6 and the design speed is 60 km/h for roads, the minimum safe distance between barriers and roadside obstacles is 1.8 m to 1.2 m, and for roads with the design speed of 80 km/h, the minimum safety distance between barriers and roadside obstacles is 3.0 m to 1.7 m, the single unit truck Ⅵ_n of enhanced barrier is at least 5% lower than F-shape barrier, the enhanced barrier contain and redirect the single unit truck in a more stable manner. The 50ms mean lateral impact force between the cargo and the barrier is close to Chinese specification method. Under the same impact condition, higher level of barrier lower Ⅵ_n significantly, however, the impact force of barrier increase greatly since the cargo more likely to collide with barrier.

The alignment design indexes of highway turning section have important influences on the safety performance of guardrail. In this paper, based on the finite element software LS-DYNA widely used in the field of highway side safety, a complex collision test model of truck and concrete guardrail is established, and simulation and vehicle tests are performed to comparatively verify the effectiveness of the model. Detailed animation describing the collision of vehicle to guardrail is obtained by simulation, which directly exhibits the safety performance of the guardrail in flat curve section. Then, the traffic lane radius, the superelevation value and the vehicle speed are used as variables to investigate and quantify the influence of main alignment indexes on the safety performance of concrete guardrail. The results show that, when the traffic lane radius is close to the ultimate minimum radius corresponding to the design velocity, the roll-over-angle of the vehicle increases, and the vehicle easily crashes to the guardrail and rolls over; that a superelevation value of 6% of the traffic lane is the critical point for the safety performance of concrete guardrail; that when the superelevation value is more than 6%, the height of the vehicle climbing along the collision surface of the guardrail may increase, and the vehicle is more likely to roll over, so that the combination of large superelevation (above 6%) and small ultimate minimum radius should be avoided during the highway design; and that,on the curve section, the collision speed has a significant impact on the safety performance of guardrail. For the integral van, the risk of rollovers significantly increases when the vehicle speed reaches 90 km/h. This research lays a theoretical foundation for the alignment safety design of highway curve sections.