Test study on the dynamic response of steel tubular crib dam subjected to impact load

In this paper, a type of steel tubular crib dam is proposed to mitigate disaster caused by boulders during debris flows. Solid impact tests are carried out to study the impact dynamic response of the structure. The response modes of the structure are summarised, and the influence of the impact height and energy on impact force and structural response is analysed. Meanwhile, the finite element simulation of the test process is conducted, and the results are consistent with the tests. The results show that the typical response modes of the structure include slight damage of member, bending failure of member, and joint failure. The displacement of the structure is affected by both the impact height and the impact energy, and the latter is the leading factor. The impact force is highly affected by the impact energy, while slightly affected by the impact height. The structure performs good overall energy dissipation ability when the pile tube is impacted, while overall energy dissipation is not obvious when the brace tube is impacted. These analyses show that the steel tubular crib dam provides limited impact resistance and needs to be strengthened.