Most of the 3D frame structures are not initially designed to resist blast loads. Due to the limitation of financial resources as well as the complex technical requirements, study the dynamic behavior of 3D frame structure under blast load, particularly for advanced materials like Ultra High Performance Concrete (UHPC), faces many challenges. Therefore, numerical simulation can be a good alternative. The objective of the research is to investigate the dynamic behavior of a UHPC building subjected to blast loading through a 3-D numerical model with the direct simulation of blast load. This building studied in this paper is a real, 6-story office building in Vietnam, which was originally designed for dead load, live load, wind, and earthquake. The building is subjected to surface blast of 500kg Trinitrotoluen (TNT) equivalent charge weight with close-in distance and a variable height of blast source. In this study, Johnson-Holmquist 2 damage model (JH-2) model is implemented to simulate the UHPC structures subjected to blast loading. Base on the theory of the JH-2 model, a subroutine, integrated with Abaqus software, is designed by the authors to calibrate the input parameters of UHPC material. A total of 8 cases of the explosion scenario are considered, in which the design of the original column is revised by using UHPC composite structure in external columns. The results indicate that there is a tremendous increase in response when the blast occurs at the mid-height of the building and the severe damage is observed in the external column in front of the explosion. The obtained result in terms of blast wave pressure during time history as well as peak deflections and damage of building under blast loading is assessed. The blast loading resistance effect of the revised design compared to the original design is also demonstrated as a beneficial alternative in blasting condition.

大多数3D框架结构最初并未设计为抵抗爆炸载荷。由于财务资源的限制以及复杂的技术要求，研究爆炸载荷下的3D框架结构的动态行为，特别是对于诸如超高性能混凝土（UHPC）之类的先进材料，面临许多挑战。因此，数值模拟可以是一个很好的选择。该研究的目的是通过直接模拟爆破载荷的3D数值模型来研究承受爆破载荷的UHPC建筑物的动力特性。本文研究的建筑物是越南真正的6层办公楼，最初是为静载，活载，风和地震而设计的。建筑物经受500kg三硝基甲苯（TNT）等效装料重量的表面爆炸，具有近距离和可变高度的爆炸源。在这项研究中，实施了Johnson-Holmquist 2损伤模型（JH-2）模型来模拟承受爆炸载荷的UHPC结构。作者基于JH-2模型的理论，设计了与Abaqus软件集成的子例程，以校准UHPC材料的输入参数。总共考虑了8种爆炸场景，其中通过在外部柱中使用UHPC复合结构来修改原始柱的设计。结果表明，当爆炸发生在建筑物的中部高度时，响应会大大增加，并且在爆炸前的外柱中观察到严重损坏。评估获得的结果，包括时间历程中的爆炸波压力以及爆炸载荷下建筑物的峰值挠度和破坏。与原始设计相比，修改后设计的抗爆载荷效果也被证明是爆破条件下的有益替代方案。