Experimental Study on Existing RC Circular Members Under Unequal Lateral Impact Train Collision

Abstract

With the fast growth of high-speed rail in recent years, derailment has become the first hidden danger of high-speed rail transportation. The high-speed train passes near the station building. So the train may derail and hit the station building. Building a high-speed railway station usually uses a reinforced concrete structure. As a result of high impact energy on the impact body, the reinforced concrete (RC) member may fail; the impact point is near the member's foot; the structural member's constraint can be considered fixed support. This paper investigates the dynamic behavior of four types of circular reinforced concrete members under unequal lateral impact loads. The RC member's failure mechanism and dynamic response addressed the significance of unequal lateral impact load. The usual circular reinforced concrete members are used as the model to perform the drop-weight impact test. The specimens' crack pattern, failure mechanism, impact, deflection, and strain time–history curves are obtained. Findings show that between the impact point and the adjacent support, shear fractures occur that fail in shear mode. Shear cracks are based on impact velocity, longitudinal reinforcement ratio, and stirrup ratio. One type is more destructive to members and nodes. A shear fracture occurs when a longitudinal reinforcement fractures towards the closer support. The effects of impact velocity, longitudinal reinforcement ratio, and stirrup ratio on the dynamic impact response are studied. The experimental results may help improve structural member impact resistance. The critical section (right side) computed the static shear resistance using shear force, whereas the maximum external load resistance determines static bending moment resistance. Understanding how circular members fail to be subjected to unequal lateral impact loads provides insight into circular RC members' impact design and damage evaluation.

Effect of the axial load on the dynamic response of the wrapped CFRP reinforced concrete column under the asymmetrical lateral impact load

“…12m, and the diameter is about 1.2m. The impact point of the derailed train is about 1.8m above the column bottom [18]. CRH2 trains have high speed and large impact energy, and the resistance of components is relatively small.…”

“…According to "Standards for Experimental Methods of Mechanical Properties of Ordinary Concrete" (GB/T 50081-2002), the average 28-day cube compressive strength of concrete was measured to be 54.97MPa for circular specimens and 43.5MPa for square specimens, the material experimental test figures as mentioned in the author's previous works [18,19]. The tensile test of the steel bar was carried out according to the "Test method for tensile test of metallic materials at room temperature" (GB/T 228-2010).…”

“…The tensile test of the steel bar was carried out according to the "Test method for tensile test of metallic materials at room temperature" (GB/T 228-2010). The mechanical properties of the steel bar are shown in [18][19][20][21].…”

Numerical study on existing RC circular section members under unequal impact collision

“…Starting with the impact body and test specimens and finishing with the specimens' damage, this part delves into each specimen's crack development process in-depth, using the different explanations of crack modes from the experimental paper 37 . The figures below depict the crack's development shape captured by a high-speed camera for each specimen and describe where the crack develops.…”

“…This research explores the numerical study of existing RC circular members' dynamic response and failure mechanism under unequal impact train collision to the experimental results reported in the author’s work 37 . For more clarity, Table 1 describes the specimens' concise properties.…”