Abstract: As the economy expands at a great speed, the number of huge commercial buildings shows a growing tendency year by year. Large commercial buildings have a strong traffic flow, high concentration of people, and great difficulty in evacuation. Because of insufficient planning time and urgent evacuation requirements, the occurrence of natural disasters and man-made catastrophes is frequently immediate and sudden, but it is difficult to create evacuation strategies in a short time following the occurrence of emergencies and emergencies. The research approach in this work is focused on creating emergency evacuation plans and methods for large commercial buildings in advance of emergencies and unexpected scenarios. Then, there is a significant scientific topic of how to quickly evacuate people from a huge commercial facility in the event of a sudden event. The study findings presented in this paper can offer a fresh theoretical foundation for the evacuation of occupants of commercial buildings following unexpected incidents, and serve as a guide for managers creating plans for such evacuations.
This study looks into the evacuation plan based on commercial buildings’ static traffic flow systems optimization. The generalized evacuation time function is defined based on the optimal theory of traffic flow systems, with the goal of achieving the shortest total generalized evacuation time of all personnel in a commercial building. The capacity constraints of the road section are added to establish an optimization model and demonstrate the uniqueness of the model solution because they are a characteristic of commercial buildings: their internal structures cannot be changed instantaneously during the evacuation of personnel. The problem is supposed to be solved via a nested generalized Lagrange multiplier approach combined with aFrank-Wolfe algorithm. The purpose of the examples in this work is to demonstrate the efficacy of the evacuation model and algorithm by using real-world crises that occurred in shopping malls.
The following are the article’s primary conclusions: First, it is demonstrated that taking into account the impact of traffic flow on the evacuation path during the evacuation process is consistent with reality by the suggested evacuation strategy for occupants of commercial buildings, which is based on the optimization theory of traffic flow systems. The commercial building scenario takes into account the passageway’s capacity limitation and its immutable capacity limitation, which aligns with the feature of commercial buildings where the interior construction cannot be instantly altered. Second, the Frank-Wolfe algorithm nested in the augmented Lagrangian algorithm can more effectively solve the optimal model of the system with the capacity constraints of the roadway. The generalized evacuation time function is defined to better describe the evacuation time when affected by the capacity constraints of the roadway. Third, by avoiding the concentration of people in particular road sections, the evacuation duration is extended when compared with that in the evacuation plans under the system optimal principle and the user-balanced concept. The comparison shows that the sum of each employee’s evacuation time under the user-balanced principle and the total evacuation time of all personnel under the system optimal concept are equal to 4/5.
Despite the fact that this paper’s evacuation strategy for commercial buildings is based on the traffic flow system optimization theory, some study outcomes have been obtained. Future studies should address the following issues: expanding the model’s application to include shopping mall evacuation procedures and creating networks for larger buildings that shouldn’t just be commercial structures.

Key words: traffic engineering, emergency evacuation, traffic flow, personnel evacuation, system optimal

摘要： 为解决商业建筑物内的人员疏散问题,引入交通流系统最优理论。以所有人员疏散的总时间最短为目标,在考虑商业建筑内通道的容量限制基础上,定义了广义人员疏散时间函数。广义人员疏散时间函数包括未受到通道容量影响的人员疏散时间以及受到通道容量影响的人员疏散时间。建立了基于交通流系统最优理论的静态人员疏散模型。模型求解采用了增广拉格朗日乘数法结合改进的Frank-Wolfe算法,并进行算例分析验证模型和算法的可行性。算例结果表明:在大型商业建筑内的人员疏散问题中存在通道容量限制不可改变并且人员疏散流量高于通道容量限制的情况,交通流系统最优理论能够很好地应用在商业建筑内人员疏散问题中。嵌套了增广拉格朗日乘数法的改进的Frank-Wolfe算法能够减少迭代次数,算例中迭代次数400次时收敛。系统最优下所有人员疏散的总时间是用户均衡下每个人员疏散时间之和的4/5。

关键词: 交通工程, 应急疏散, 交通流, 人员疏散, 系统最优