use of evacnet for modeling building evacuations
TRANSCRIPT
Use of EVACNET for Modeling Building Evacuations
Introduction
• Developed by Francis and Kisko, the University of Florida
• EVACNET is a interactive computer program that models building evacuations
• EVACNET takes macroscopic coarse network approach
• EVACNET provides ‘minimum’ amount of evacuation time
Acquire EVACNET4
• EVACNET4 is now FREE.
• One can download from the link: http://www.ise.ufl.edu/kisko/files/evacnet/
Modeling ProceduresDecomposition of the building into network
Supplying data to EVACNET (Nodes and arcs)
Verification of input
Graphical Representation of the network model
Run EVACNET
Analyzing Results
Decomposition: representation as network
1V
2V
3V 5V
4V
6V
Nodes: components of the building
Arcs: viable passageways between the defined nodes
Capacity of node: the upper limit on the number of people that can be contained in the building component
Flow capacity of arc: the upper limit on the number of people that can traverse
Node
Arc
Define nodes
• Let the node represent a single room (or hall, stair, lobby, etc.).
• Combine a set of adjacent rooms into a single node.
• Split up an area, such as a hall, into several nodes.
The number of nodes should not be so many as to make the network model unmanageable.
Node Specifications
• Unique ‘ID’ of a node
• Three parts: node type (two character ), node sequence number, floor number
Example: WP2.3
WP – Node type (Work Place) 2 – Sequence number 0~99 . – Required delimiter 3 – floor number 0~255
WP02.003 is invalid
Suggested Nodes types by EVACNET
Node Type Node Type Description
"WP" Work Place
"HA" Hall
"SW" Stairwell
"LA" Landing
"LO" Lobby
"ES" Escalator
Special Node Types
• “DS“ : destination nodes. Every EVACNET model must have at least one destination node
• “EL“: elevators/lifts, running on a specified schedule
Arcs
• Viable doorways/passageways between the defined nodes
• Directional: from node1 to node2
• It is allowable to have two arcs connecting two nodes
• No arcs are permitted to leave "DS" (destination) nodes
Arc Specifications
• “from" node specification - the "to" node specification
Example: WP1.3-HA1.3
(Room 301 to third floor hall)
cannot have intervening blanks
Graphical Representation
• An EVACNET network model can and should be drawn graphically
Data required to supply
• node capacity
• node initial contents
• arc flow capacity
• arc transit time
must be represented as integers
Node capacity
• maximum number of people that can be contained in the physical space allocated to the node
• This capacity depends on the usable area associated with the node and the maximum assumed density of people in the node
Example: area=10 m2
max. density=4 persons/ m2 Node capacity=40 (persons)
Node initial contents
• How many/where the people are at the beginning of an evacuation
• Must be less than or equal to node capacity
• Default is zero
Refer to MoE-Table 1
Two attributes of ‘DS’ node
• upper and lower bounds on the number of evacuees allowed to reach the destination
• do not have to be supplied
• The default values are infinity and zero respectively
Arc flow capacity
• Upper bound on the number of people that can traverse an arc per time period
• Determined by the factor limiting the flow from one node to another
• The limiting factor is usually the minimum passageway width, such as a doorway or stairway width, between nodes
• Greater than zero
Arc transit time
• Is the number of time periods it takes to travel from the approximate midpoint of one node to the midpoint of another node
• Not the amount of time it takes to walk through a doorway
• Time period is 5 seconds
• Greater than zero
Adding Data to a Graphic Model
Run EVACNET
ANALYZING RESULTS • SUMMARY OF RESULTS • DESTINATION ALLOCATION• TOTAL ARC MOVEMENT • BOTTLENECKS• FLOOR CLEARING TIME• UNCONGESTED TIMES • NODE CLEARING TIME • BUILDING EVACUATION PROFILE • DESTINATION EVACUATION PROFILE • NODE CONTENTS PROFILE • NODE CONTENTS SNAPSHOT • ARC MOVEMENT PROFILE • BOTTLENECK PROFILE • NON-EVACUEE ALLOCATION
Assumptions of EVACNET
• EVACNET is a linear modeling system. Dynamic arc capacities and arc traversal times do not change over time.
• EVACNET does not model behavioral aspects. The only actions that are modeled are those that lead to achieving the minimum evacuation time.
• EVACNET is based on a global viewpoint; not an individual viewpoint. This means that in achieving the optimal evacuation plan
Components of Total Evacuation Time
Fire Occurs
Time
Time of Fire Detection
Pre-movement time
Flow/Movement Time
Total Evacuation Time