NCST Technical 

Investigation of 

Hurricane Maria’s 

Impacts on Puerto Rico:

Preliminary Project Plan for Evaluation 

of Critical Building Performance

Aug 30, 2018

NCST Advisory 

Committee Meeting

Joseph Main

Associate Leader, NCST Investigation of Hurricane Maria

National Institute of Standards and Technology
Goal 2: The Performance of Representative Critical Buildings, 

and Designated Safe Areas in those Buildings, 

Including their Dependence on Lifelines
Project: Performance of Critical Buildings

Objective: To characterize the performance of critical buildings in 

Hurricane Maria by (1) documenting failures of structural systems, 

building envelopes, and rooftop equipment, along with the resulting 

intrusion of wind-driven rain, interior damage, and loss of function for 

a representative sample of hospitals and schools, (2) identifying 

dependencies in loss of function on lifelines, (3) characterizing wind 

loads on building envelopes and rooftop equipment through wind 

tunnel testing for a subset of these hospitals and schools to correlate 

with observed damage, and (4) evaluating the adequacy of existing 

selection criteria and design requirements for storm shelters.

3
Background

Observations from preliminary reconnaissance of engineered buildings:

• Limited structural damage to reinforced concrete 

and concrete-block buildings with concrete roofs

• Some failures of non-concrete roofs (wood or steel 

frame) on reinforced concrete and concrete-block 

buildings

• Wind-induced damage to and 

failure of metal building systems, 

potentially due to corrosion
Background

Even for engineered buildings with good structural performance, 

extensive nonstructural damage and loss of function was observed as 

a result of water intrusion through building envelopes via:

• Failures of rooftop equipment

• Damage to roof coverings

• Rainfall ponding on the roof

• Damage to windows and doors

• Wind-driven rain penetration, even 

through undamaged cladding
Preliminary Project Plan (1/3)

Documenting Performance of Critical Buildings:

• Identify available data on characteristics and performance of hospitals and schools in 

Hurricane Maria in coordination with federal partners (through National Disaster 

Recovery Framework)

• Select a representative sample of hospitals, schools, and emergency shelters for 

detailed study, with consideration of available information on the buildings, the 

hazards, and social factors

• Perform detailed on-site evaluations of the selected sample of critical buildings:

− Building characteristics; design criteria; construction, inspection, and maintenance practices

− Structural and non-structural damage, loss of functionality, dependence on lifelines

• Select a subset of the critical buildings for forensic wind-tunnel testing

• Evaluate the performance of the critical buildings with consideration of:

− Wind loads and other hazard levels encountered during Hurricane Maria

− Code and standard requirements, including consideration of seismic hazards
Preliminary Project Plan (2/3)

Forensic Wind Tunnel Testing of Selected Critical Buildings:

• Wind tunnel testing is planned for a subset of the sample of critical buildings, where 

detailed characterization of the wind loads would be warranted for evaluation of 

building performance

• Buildings models will be extensively instrumented:

• Pressure taps to measure pressures on the building envelope (e.g., roof, walls, windows, doors)

• Pressure taps or force balances to measure wind loads on rooftop equipment

• Surrounding buildings and terrain will be included in area models

• Selected tests may be repeated with varying conditions:

• With and without surrounding buildings, to quantify their effect on the resultant wind loads

• With different configurations of rooftop equipment

• Directional pressure and force coefficients from wind tunnel testing will be combined 

with the time-dependent hurricane wind-field model to estimate wind load histories 

during Hurricane Maria, which will be used in evaluating building performance
Preliminary Project Plan (3/3)

Evaluation of Storm Shelter Section Criteria and Design Requirements:

• Collect relevant data on the hurricane shelter program in Puerto Rico:

− Shelter selection criteria and process

− Shelter facilities used during Hurricane Maria

− Storm impact on these facilities, including damage and any injuries or fatalities

• Determine the hazard levels experienced at shelter site locations

• Evaluate shelter performance and selection criteria in consideration of:

− Hazard levels experienced during Hurricane Maria

− Code and standard requirements

• Develop findings and recommendations based on these results
FY18 Planning Tasks 

(Presented at NCST Advisory Committee Meeting on May 16, 2018)

1. Other agencies with information on the performance of schools and hospitals 

will be identified, and plans will be made on best ways to reach out

2. A sampling strategy will be developed, and a representative sample of critical 

buildings will be selected for detailed study

3. Buildings will be identified where wind tunnel testing would be warranted for 

evaluating building performance

4. Staff with GIS expertise may be hired or detailed to assist the Team

5. Contract specifications will be developed:

– Local engineering support for evaluation of building performance

– Forensic wind tunnel testing of selected critical building models
FY18 Planning Tasks – PROGRESS (1/3)

1. Other agencies with information on the performance of schools and 

hospitals will be identified, and plans will be made on best ways to 

reach out

• The following potential sources of information on building performance have 

been identified:

− Results of USACE School Assessments under FEMA Mission Assignment (Fall 2017)

− Public Assistance Project Worksheets for hospitals, schools, and storm shelters

− Results of FEMA School Evaluations (Summer 2018)

• We are currently coordinating with FEMA in evaluating the potential need for 

updates to our existing Memorandum of Understanding, including an 

Information Sharing Agreement to facilitate sharing of data
FY18 Planning Tasks – PROGRESS (2/3)

2. A sampling strategy will be developed, and a representative sample 

of critical buildings will be selected for detailed study

• To support the selection of buildings for detailed study, a complete list of 

hospitals and official emergency shelters (most of which are schools) in 

Puerto Rico has been compiled, along with GPS coordinates, and has been 

organized in GIS format to facilitate mapping

• NIST will host a public meeting to discuss the state-of-the-practice in postdisaster field data collection methods, including sampling methodologies 

across multiple disciplines

3. Buildings will be identified where wind tunnel testing would be 

warranted for evaluating building performance

• Factors of potential interest for wind tunnel testing are being noted as 

information is collected (e.g., surrounding topography, structural failures, 

failures of rooftop equipment), and final selection will occur after baseline 

and detailed building evaluations are performed
FY18 Planning Tasks – PROGRESS (3/3)

4. Staff with GIS expertise may be hired or detailed to assist the Team

• An announcement for a detail opportunity was shared with partnering federal 

agencies through the NWIRP and NEHRP working groups, and other hiring 

mechanisms are also being considered

• Applicants are currently being interviewed

5. Contract specifications will be developed

– Local engineering support for evaluation of building performance

– Forensic wind tunnel testing of selected critical building models

• Specifications for these contracts have been developed and are working their way 

through the NIST approval and procurement process

• Anticipated contract awards/start dates in Fall 2018

• Planned wind tunnel testing approach was described previously

• Planned approach for evaluation of building performance is described in the 

following slides
Planned Approach: Evaluation of Building Performance (1/3)

• The principal goal is for the Contractor to document the performance of 

selected hospitals, schools, and storm shelters during Hurricane Maria

• The main tasks for the Contractor will be the completion of baseline building 

evaluations for at least 20 buildings, with further detailed evaluation for at 

least 10 buildings

• The Contractor will also be responsible for organization of information 

collected during the evaluations in a suitable format to facilitate analysis by 

the NIST Team

• The information gathered by the Contractor will be analyzed by NIST to 

determine candidate buildings for wind tunnel testing or other detailed 

analysis
Planned Approach: Evaluation of Building Performance (2/3)

Baseline building evaluations will include the following tasks:

• Conduct technical discussions with relevant building personnel and obtain photographs (with 

associated permissions), inspection reports, and other information to provide evidence of 

direct and indirect damages 

• Perform inspections of the building and surrounding area and take photographs to provide 

evidence of direct and indirect damages

• Document significant sources of water intrusion that contributed to interior damage 

• Document damages to building-located communication towers, other wireless 

communication equipment, and infrastructure connections, including electrical and water 

connections 

• Document any loss of function for the building along with the associated factors that 

contributed to the loss of function 

• Document operational conditions of the building if it was occupied during the storm, and any 

fatalities or injuries
Planned Approach: Evaluation of Building Performance (3/3)

Detailed building evaluations may include tasks such as the following:

• Document the applicable building code and standards used in the design of the building

• Obtain design documents, including design drawings and calculations

• Document the functional intent of the building

• Document as-built conditions of the building or a portion thereof 

• Obtain construction-related records such as building permits and building inspection 

reports

• Document relevant pre-storm building maintenance, repair, and operational activities 

that may have affected the building performance during Hurricane Maria 

• Obtain aerial photographs of the building using an aerial drone, and assemble a threedimensional model of the building