Stair Width Research Articles

Comparative analysis of two evacuation simulation tools when applied to high-rise residential buildings

Currently there are numerous emergency evacuation simulation tools with varying levels of sophistication and differing capabilities. It is expected that investigating the same scenarios using different tools might not give the same outcome. This paper illustrates how a microscopic agent-based modelling tool (Pathfinder) and a macroscopic flow-based modelling tool (Evacuationz) can be setup to investigate high-rise residential building evacuations in comparable ways by varying configuration parameters. Both tools represent individual agents with associated characteristics (e.g., walking speed and pre-evacuation delay). These are varied in the scenarios examined to stress-test the designs or explore the impact of design/procedural changes.The two tools differ in how they deal with the building geometry and therefore have different algorithms to manage evacuee movement. In this work, assumed performance parameters (e.g., travel speeds, spacing, etc.) have been calibrated to better align the conditions represented in the tools and the outcomes produced across the scenarios examined. This then allows the tools to function at their respective levels of sophistication and granularity (providing different perspectives on performance) but adopt a more equivalent performance baseline given the calibration effort.The use of two tools increased confidence in the predictions, and also allowed for an examination of a wider range of scenario conditions such as number of stairs, stair width, and building size, given the different computational expense associated with the tools.

A Case Study on the Evacuation of People during a Fire in the Workshop of a Large Factory

A workshop, as a crowded place, is quite easy to cause serious casualties and economic losses once there is a fire. In this paper, Pathfinder software was used to simulate fire emergency evacuation in a workshop of a large factory with building structural symmetry. According to the simulation results, several obstacles to the evacuation were discovered and further analyzed. The results showed that the main factors affecting the evacuation were the width of exits, the distribution of occupants and the effective evacuation width of stairs. Among them, only changing the width of exits had little influence on shortening evacuation time. While changing the effective evacuation width of stairs could greatly relieve the evacuation pressure, every increase of 0.5 m in the width of the staircase could shorten the evacuation time by 30.0 s. Meanwhile, the larger the number of people in high-rise buildings, the longer the evacuation time was. Therefore, the means of restricting people from entering the high-rise buildings in batches could be used to prevent personnel from being evacuated in time when a fire incident occurs.

고시원 피난계단 폭의 변화에 따른 피난 안전성 평가

This study focused on the fact that multiple living facilities (gosiwons) can have more rooms on the same site by taking advantage of the fact that the parking area is smaller than the parking lot area (as stipulated by the parking lot law) and multifamily housing, and further evaluated the performance-oriented design of a gosiwon's firefighting facilities. By creating a scenario using standard guidelines (2021), fire and evacuation simulation programs were used to calculate the evacuation time according to life safety standards, with the number of people who could evacuate being calculated according to the change in the width of the escape stairs at the Gosiwon facility. As a result of this analysis, the group that underwent evacuation training and Scenario 6, in which the width of the evacuation stairs was expanded to 2m, showed the shortest evacuation time of 296.3 seconds. As a result of conducting an evacuation simulation for the same building without changing the width of the stairs and fire drills, the evacuation time was shortened by 165.2 seconds from the evacuation time of 461.5 seconds. As a result of this analysis, it is necessary to add the width of the evacuation stairs to the types of safety facilities under the Multi-Use Business Act so as to improve the evacuation safety of gosiwons. In addition, multi-use establishments with 11 or more floors were added to the fire training and education targets as stipulated in the Fire Prevention Act, allowing training to be conducted together with fire agencies, thereby securing evacuation safety and laying the foundation for the revision of the laws.

Modeling of emergency evacuation in high rise buildings considering congestion at stairs based on Markov chains

High-rise buildings are vulnerable to encountering fires or other emergencies at any time, requiring an immediate evacuation of occupants. In the context of building evacuations, various engineering parameters are often utilized to evaluate the time required for people to reach a safe place when descending a staircase. A discrete-time Markov chain model is proposed to evaluate the evacuation time of the occupants in such circumstances by taking into consideration factors like merging at the stairs and congestion on the floor. Based on the congestion probabilities with respect to the number of evacuees in the building and other human behavior factors that slow down the rate of evacuation, non-congested and congested scenarios are evaluated. The effect of the critical parameters that influenced the evacuation process in the high-rise building, such as walking speed, number of evacuees, and effective stair width, is evaluated in both scenarios. The findings indicate an optimal evacuation speed of 0.7–1.4 m/s. The effective width of the stair is suggested to be between 1.6 and 2.4 m using the model. The simulation results are in good accordance with the SFPE method, the NIST egress simulator, and the agent-based model results.

Obstacle detection and autonomous stair climbing of a miniature jumping robot

Miniature jumping robots (MJRs) have difficulty executing autonomous movements in unstructured environments with obstacles because of their limited perception and computing resources. This study investigates the obstacle detection and autonomous stair climbing methods for MJRs. We propose an obstacle detection method based on a combination of attitude and distance detections, as well as MJRs’ motion. A MEMS inertial sensor collects the yaw angle of the robot, and a ranging sensor senses the distance between the robot and the obstacle to estimate the size of the obstacle. We also propose an autonomous stair climbing algorithm based on the obstacle detection method. The robot can detect the height and width of stairs and its position relative to the stairs and then repeatedly jump to climb them step by step. Moreover, the height, width, and position are sent to a control terminal through a wireless sensor network to update the information regarding the MJR and stairs in a control interface. Furthermore, we conduct stair detection, modeling, and stair climbing experiments on the MJR and obtain acceptable precisions for autonomous obstacle negotiation. Thus, the proposed obstacle detection and stair climbing methods can enhance the locomotion capability of the MJR in environmental monitoring, search and rescue, etc.

Study on crowd evacuation in subway transfer station fires based on numerical simulation

In order to study the influencing factors of fire evacuation bottleneck and evacuation time in subway transfer station, a subway transfer station model was built by Pathfinder to simulate the emergency evacuation of passengers in fire. Using the control variable method, the evacuation under different conditions is simulated by changing the parameters. The effects of the use of escalators, the speed of escalators, preference for stairs and escalators,the use of escalators, the familiarity of exits, the speed of personnel movement and the width of stairs on evacuation time are discussed and analyzed. The results show that the fire evacuation bottleneck of subway transfer station is each stair entrance. Evacuation time can be shortened by increasing the speed of escalators, increasing the proportion of escalator walkers, reducing the proportion of passengers who choose familiar exits to escape, increasing the speed of passengers and increasing the width of stairs.

A Study on the Analysis of Vertical Walking Speed Considering the Confluence of Occupants in the Stairwell of a High-rise Building

In a fire incident case in a modern high-rise complex building, most occupants use the stairs to evacuate; hence, it is critical to secure the safety of vertical escape routes, such as the stairs. However, in Korea, the size of the stairwell is stipulated as a universal standard, and there are insufficient regulations and studies on the behavioral characteristics of occupants that may occur during the vertical evacuation of buildings. Therefore, in the evacuation experiment conducted at the W University in Japan, the relationship between the density and velocity of the occupants and the flow coefficient were analyzed during merging in the stairwell to derive a regression equation. When the stair width acted as a variable, the behavioral characteristics of the occupants and the evacuation time inside the stairwell were analyzed to obtain the basic data for improving the evacuation safety in the stairwell.

Analysis of the Impact of Decreasing the Width of Direct Stairs in Apartments on RSET for All Occupants in Korea

This study analyzed the RSETs for 11-story or less apartments where the building-related laws were not retroactively applied, with consideration of the decrease of direct stairs width due to obstacles piled up on the direct stairs. The RSET was shown to be 631.8 seconds when the width of the direct stairs was 1,260mm. The evacuation time exceeded 5 minutes even when there were no obstacles due to the delayed evacuation start time. The risk increased when the width of the direct stairs was decreased to 960mm, 760mm, and 560mm because of obstacles, and the RSETs were 768.8 seconds, 803.3 seconds, and 834.4 seconds respectively. There are various ways to eliminate the occurrence of obstacles on direct stairs which increase RSET : First, it is necessary to remove the exception that permits the placement of obstacles on the stairs. Second, penalties for the placement of obstacles on the direct stairs should be enforced as written. Third, the fire safety managers need the authority to act on behalf of the fire officials. Lastly, it is necessary to encourage residents to report instances of obstacle accumulation. Henceforth, more research is needed on the spread speed of smoke and toxic gases depending on whether fire doors are installed through fire simulation.

Study on Pedestrian Dynamics in Stairwell Based on Circle-Based Floor Field

Due to constraint land, more and more high-rise buildings are built in cities. It is unsafe to evacuate by elevators, thus stairs has an important impact on evacuation. So it is of great significance to analyze evacuation in stairwell. However, few researchers could reproduce occupant arc trajectories at the mid-landing in stairwell. A stair model based on circle-based floor field (Stair Circle-based Optimal Step Model — SCOSM) is proposed to investigate human performance in stairwell, in which occupants could make a turn with a certain point and move like as an arc. SCOSM is testified to validate by comparing simulated results and experimental datasets in respect of whole evacuation time and net person for each floor. What is more, the model is used to study the effect of interface. It is found when width of stairs (S1) is equal to the width of mid-landing (S2), pedestrian flow is dominated by the width of mid-landing (S2). As for effect of stair geometry on merging, structures except scenario a are inclined to preferring occupants from floor. The studies in this paper could help offer engineers a technical foundation for codes and fire protection design.

Emergency evacuation simulation at starting connection of cross-sea bridge: Case study on Haicang Avenue Subway Station in Xiamen Rail Transit Line

Due to the underground nature and dense concentration of people around transit stations, emergency evacuation during fire accidents can become a noticeable problem in subways. This study numerically simulated the crowd dynamics during fire evacuation in the Haicang Avenue Subway Station in Xiamen. The uniqueness of the case study is that this subway station is built as the starting connection of a cross-sea bridge at the seashore. Total evacuation time was affected by factors such as the width of the evacuation channel, proximity to exits, crowd density, and evacuation speed. Parameters in the computer modelling were obtained through proportional measurement algorithms and on-the-spot investigations, video recording, and personnel tracking at a mirror station. The study simulated the evacuation process in four scenarios using variables such as the number of passengers and width of evacuation stairs. When crowd dispersion increases, a longer evacuation time is needed. Suggestions are made to optimise the positions of outlets and to increase the width of exits to alleviate congestion.

Modeling Evacuation of High-Rise Buildings Based on Intelligence Decision P System

High-rise buildings usually have more complex architectural structures and hold more people than single-storey buildings. Currently, crowd management under emergent conditions, especially rapid evacuations of high-rise buildings, is a worldwide problem. In this study, a bio-inspired simulation technology extracted from a cell migration process, namely Intelligent Decision System (IDPS), was used to model the dynamic evacuation of high-rise buildings and calculate the evacuation time for different scenarios. This work was motivated by the comparability between the pedestrian movement behavior and cell migration process. Specific structure information of high architecture was also described in IDPS. A case study was done about evacuation simulation of a 12-storey teaching building in China University of Geosciences in Beijing. The simulation results showed that evacuation time varied with different parameters, such as density threshold, interaction probability, walking speed, population distribution, and stair width. With the proper density threshold and good interaction probability, the load balance of staircases and exits can be improved. For staircases with high utilization ratios, it was recommended that the evacuation process can be accelerated by widening the staircases appropriately. Finally, the impact of initial number of evacuees at each floor level was also analyzed in view of safety management.

Dependence of the human flow density from the staircase and exit width

The article studies the dependence of the human flow density on two main parameters: the width of the staircase and the number of people on the floor. It was established that violation of standards in terms of the entrance door width and the presence of a stair hall have a strong influence on the total time of evacuation due to the formation of clusters. The tabular dependence of the maximum human flow density on the staircase width on the number of people per floor was obtained. On the basis of this dependence, the graph was built, which can be used in the stair width design, taking into account the allowable human flows density in the case of known average number of people on each floor of the building.

Incorporating Human Interaction into Stair Egress with an Application to Minimum Stair Width

Recently, this journal published an article (Peacock et al. in Fire Technol 53:845–871, 2017) describing a study done by the National Institute of Standards and Technology’s Engineering Laboratory. That article provides a description of data collected during fire drill evacuations of 11 office buildings and 3 residential buildings throughout the United States. A total of 32 stairs were observed. These data were analyzed with two goals in mind: to present the self-exciting Hawkes point process as a means to capture occupant interactions in stair exit processes, and to use this point process representation to derive a minimum stair width determination that compensates for human interaction. By way of accomplishing these goals, it is shown by modeling occupant exit times as a point process more information than flow rate is extracted. This additional information resides in the process’s intensity function, i.e., the instantaneous exit rate of occupants through a stair exit, which has units of persons per unit time. For example, it is shown that the following behavior is captured by a Hawkes intensity. When a slow moving occupant on a stair is met, occupants behind either decrease their speed and follow that occupant or move to pass the occupant. Our results indicate that a larger minimum stair width would help accommodate movement in stairs caused by these types of interactions. By modeling the exit process as a Hawkes point process and using hydraulic model equations, we derived a point estimate 1.308 m for minimum stair width and a 95% confidence interval [1.193 m, 1.334 m] bounding minimum stair width, whereas the normative minimum stair width value set by the U.S. building code is 1.12 m.

Numerical simulation of dormitory building fire and personnel escape based on Pyrosim and Pathfinder

To analyze the fire risk in dormitory buildings, one dormitory of a university was taken as the subject to build a model using Pyrosim. This paper has analyzed the temperature, visibility, smoke layer height, heat flow, and smoke movement with all windows and doors opened and compared these with conditions when the fire origin room had closed windows. The results show that, with all windows opened, the highest temperature area is the fire origin room and the fire floor temperature is higher than the other floors. The closer to the fire source, the lower the visibility. With window closed, the fire origin room temperature and heat flow are much higher than with window open while the smoke layer height is much lower. Horizontal corridors and stairs are more seriously influenced by the smoke. When all windows are opened, rooms above are more seriously influenced by the smoke. Pathfinder simulation results show that the best time to escape is within 164.8s. In order not to affect the safety of personnel evacuation, the width of exit doors should be no less than 3 m and stair width should be no less than 1.75 m.

Experimental study on walking preference during high-rise stair evacuation under different ground illuminations

Movements on stairs have attracted a lot of researchers to study in order to help evacuate as fast as possible. However, there has been much less awareness for this issue on preference for stairs and human behaviors under different illuminations. Experiments were carried out to study the human movement characteristics and human behavior performance when pedestrians walked down stairs alone. By extracting the positions of pedestrians on cameras, preference and movement characteristics were studied and discussed, and it is found that pedestrians would like to choose inner side stairs rather than outside stairs when stairs were divided into 2 parts. Besides, some conclusions can be drawn when stairs are divided into three components: when entering into sections under conditions of 100% and 12% illumination, both females and males have a preference for middle areas when the width of stairs is about 130 cm, but the preference would change with illumination conditions. Furthermore, when the illumination is 0%, the mean velocity is 0.50 ± 0.14 m/s. In addition, the usability to handrails helps to reduce time taken on interfaces or mid-landings. The results help to better understand movement during stair evacuations and are important for constructing or improving evacuation models.

Insulation Design for Non-Heated Stairwells of Residences in Severe Cold Zones

With the continuous improvement of energy efficiency standards, the insulation design of stairwells is further strengthened. As some problems exist in insulation design for non-heated stairwells in engineering practices, the author proposes specific requirements on insulation design for non-heated stairwells of residences in severe cold zones by choosing reasonable insulation materials and construction methods to meet the requirements of stair width.

Evacuation Time of the Facilities in Rail Transit Study and Simulation

Urban rail transit is one of the important transportation means. Passenger evacuation capacity of subway station is importance for rail operation safety. This article studied the time variation about different numbers of evacuated people under the different stairs width. And it forced on the variation of the evacuation time under different stair widths. By considering the mutual repulsion between pedestrian and wall, and among pedestrians, the article used the anylogic simulation software to simulate and got the evacuation time under different stair-width. When down-stair width is beyond by 3.5m, down-stair-width increasing is unobvious to shorten the evacuation time. Finally, the article explains differences between two results by comparing analysis of simulation results and calculation results.

Influences of exit and stair conditions on human evacuation in a dormitory

Evacuation processes of students are investigated by experiment and simulation. The experiment is performed for students evacuating from a dormitory with an exit and stairs. FDS+Evac is proposed to simulate the exit and stair dynamics of occupant evacuation. Concerning the exit and stair widths, we put forward some useful standpoints. Good agreement is achieved between the predicted results and experimental results. With the increase of exit width, a significant stratification phenomenon will be found in flow rate. Stratification phenomenon is that two different stable flow rates will emerge during the evacuation. And the flow rate curve looks like a ladder. The larger the exit width, the earlier the stratification phenomenon appears. When exit width is more than 2.0 m, the flow rate of each exit width is divided into two stable stages, and the evacuation times show almost no change. The judgment that the existence of stairs causes flow stratification is reasonable. By changing the width of the stairs, we proved that judgment. The smaller the width of BC, the earlier the stratification appears. We found that scenario 5 is the most adverse circumstance. Those results are helpful in performance-based design of buildings.

복도·계단 폭 변화를 통한 피난실험에서 피난행태에 미치는 영향요인 분석

본 연구는 복도와 계단의 폭 변화에 따른 피난밀도 변화가 피난행태에 미치는 영향을 분석하고, 화재에 대한 불안감에 대해 영향을 미치는 변인들의 관계를 분석하는 것을 그 목적으로 하고 있다. 이를 위하여 대학교육시설재실 자(대학생)를 대상으로 복도 및 계단의 폭을 조정하여 밀도변화에 따른 피난실험을 실시하고, 피난실험 후 설문조사를 통하여 피난밀도의 변화가 피난행태 및 화재에 대한 불안감에 미치는 주요요인들의 관계를 분석하였다. 연구결과는 다 음과 같다. 첫째, 피난행태에 영향을 미치는 변수들을 대상으로 요인분석을 실시한 결과, 리더십(결단력, 설득력, 통솔 력, 자신감), 친화력(책임감, 사교성, 의욕적, 신중한) 그리고 독단적 성격(건방, 자기중심적, 경박, 무분별)으로 구분되는 심리적 요인이 중요하게 대두되며, 출구위치, 소방설비, 피난로 축소 등으로 유형화되는 환경적 요인, 그리고 개인적 요인(연령, 사용기간)이 추출되었다. 둘째, 화재에 대한 불안감에 영향을 미치는 가장 중요한 요인은 화재대피방법, 건 축물친숙도 및 친화적 성격과 높은 관련성을 지니고 있으며, 일반인들이 잘 알지 못하는 소방설비에 친숙도, 성별 및 연령 등의 개인적 요인, 독단적 성격, 리더적 성격 등은 부차적인 영향을 미치고 있는 것으로 나타나고 있다.

Observation study of pedestrian flow on staircases with different dimensions under normal and emergency conditions

Compared with horizontal motion, there were several characteristics in staircase movement. This study focused on the movement characteristics in staircases of typical student crowds and the quantitative relations of flow rate–speed–density in different dimensions of staircases and different circumstances were obtained. Basic data concerning daily movement when classes were over and an evacuation drill for college students was collected through analysis of video observation. From the analysis, the following conclusions can be given: some typical characteristics of pedestrian movement in staircases were found, such as queuing behavior at platform, merging flow at staircase entrance, and subgroup behavior. Movement on stairs was markedly slower than the horizontal motions. In normal condition, the number and initial speed of students entering the staircase affected observably the pedestrians flow, and the impact of staircase attributes (riser, tread, slope, etc.) cannot be neglected. In different conditions, the characteristics of pedestrian movement were quite different, and the influence of the speed on the density was more significant in the emergency condition. The study highlighted the amassment phenomenon at the bottom of the staircase and the potential influence of stair widths to evacuation efficiency in evacuation drill.