leveraging mobile technology and data management ...

SECED 2015 Conference: Earthquake Risk and Engineering towards a Resilient World 9-10 July 2015, Cambridge UK

LEVERAGING MOBILE TECHNOLOGY AND DATA MANAGEMENT TO MAXIMISE THE EFFICIENCY AND BENEFITS OF ASCE 31-03 SEISMIC EVALUATIONS ON VERY LARGE GLOBAL BUILDING PORTFOLIOS Patrick NOLL1, Nancy ZEKIOGLU2, Huseyin DARAMA3 and Simon REES4 Abstract: Arup recently conducted an ASCE 31-03 Tier 1 seismic screening of a large international portfolio of buildings for a global portfolio holder. The study involved the assessment of a wide range of building types across all regions of the world ranging from retail locations to data centres and corporate offices. Mobile technology was used in combination with data automation in order to deliver this evaluation in a timely manner. A custom tablet application was developed which reported all Tier 1 findings to a database. Post processing of this data was automated to save time, minimize the risk of errors and create consistent reports for the client. This case study shares an approach to conducting a successful large scale building screening process, utilizing automated processes to achieve a uniform reporting style across the globe in a short amount of time and creating a database which allows the building owner/client to decide on further steps based on the evaluation findings.

Introduction Arup was approached by a global operating client, seeking support and engineering consultancy with the right expertise, knowledge and manpower to provide seismic evaluation for many of their buildings in accordance with current seismic knowledge. The owner of an individual building and a client that holds a large portfolio of properties may have widely varying interests when approaching a seismic assessment study. In the case of some large portfolio holders, such as with the client in this case study, many of the occupants are employees. The responsibility for occupant safety and the financial risk of lost operating time after an earthquake is of high importance to such a client. In addition, some of the properties are leased and are candidates for purchase. While the concerns and risks are the same as for the owner of a smaller portfolio, the way in which the resulting information is processed and acted upon is not. In order to make good decisions on a large portfolio, the results need to be standardized, comparable and actionable. Of common concern is the structural behaviour during an earthquake and the occupancy possibilities after an earthquake. The development and improvement of building codes over the years has naturally led to newer buildings that are seismically safer than their older counterparts. The seismic safety of buildings designed to older code versions and of buildings located in regions without modern seismic codes is questionable and it is advisable to the building owner to evaluate the structure. The American standard ASCE 41-13 “Seismic Evaluation and Retrofit of Existing Buildings” (2014) is probably the most widely adopted standard in the engineering industry.

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Senior Engineer, Arup, Los Angeles, [email protected] Senior Engineer, Arup, Los Angeles, [email protected] 3 Associate, Arup, Los Angeles, [email protected] 4 Associate Principal, Arup, Los Angeles, [email protected] 2

Patrick NOLL, Nancy ZEKIOGLU, Huseyin DARAMA and Simon REES

Seismic Risk & Awareness Several initiatives are currently underway to evaluate the building stock of cities in areas of high seismicity. For example, the City of Los Angeles released a “Resiliency by Design” (2014) proposal, which includes the evaluation and mandatory retrofit of soft first story and concrete moment frame buildings prior to 1980. If the mayor’s proposal passes, Los Angeles will be the first city adopting the US Resiliency Council Building Rating System with a mandatory evaluation and retrofit program. Similarly the City of San Francisco has introduced a “Mandatory Soft Story Retrofit Program” (2013), to ensure the safety and resiliency of the city, addressing soft story wood framed buildings constructed 1978 or earlier. These two examples show the increase of awareness for seismic safety and resiliency of buildings. The same applies to the private sector, where large portfolio holders show an increasing interest in evaluating and assessing their buildings in order to be prepared for a seismic event and to minimize risks. ASCE 31-03 Seismic Evaluation This case study presents a seismic evaluation project which was initiated in early 2014 and carried out in accordance with ASCE 31-03 “Seismic Evaluation of Existing Buildings” (2003). The current seismic evaluation standard ASCE 41-13 “Seismic Evaluation and Retrofit of Existing Buildings” (2014) replaced ASCE 31-03 in 2014 but was not yet implemented when this project kicked off. Because of the implementation date this case study refers to the older standard and not to its recent replacement. ASCE 31-03 is a three tiered evaluation process and this case study focuses on the first stage of the project, which only covered the Tier 1 screening process. In the following, the terms “Seismic Evaluation”, “Assessment” or “Screening” are interchangeable and refer to the Tier 1 effort of this project phase. Tier 2 and Tier 3 evaluations are part of a currently ongoing second project phase that involves only those buildings where Tier 1 findings suggested a further evaluation. The project required the evaluation of many buildings located around the globe. Contract negotiations, legal agreements and confidentially requirements were lengthy and, when complete, the client required additional time to finalize their list of building locations that were to be included in this project phase. The client’s portfolio, which comprises roughly 10.000 locations worldwide, was filtered by a number of parameters, such as level of seismicity and various business interest aspects, to determine which buildings should be evaluated to deliver the maximum value from the study. The final list was pared down to 385 buildings world-wide. Figure 1 illustrates the location of buildings, with the size of the dots indicating the number of buildings in that region. In addition the exact number of buildings per country are shown in Table 1. By the time that the building location list was finalized, a seven month time frame was left to complete this project, including desk studies, site visits and reporting. It was necessary to also include a certain amount of time for project management, given the size and geographical spread of this project. Between the start-up processes and the wrap-up reporting, the time available to perform 385 site visits was squeezed down to only four months. Even prior to winning the project, it was very clear to the project team that new methodologies and new technology were needed to organise, manage and deliver a high quality project.

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Figure 1. Global Building Portfolio and Location

Table 1. Number of Evaluated Buildings per Country

Taiwan

Australia India

India

Malaysia

Philippines

China

Thailand

New Zealand

Guam

Greece

15

14

10

5

2

2

1

1

7

Puerto Rico 7

40

Costa Rica 5

Jamaica

Honduras 5

1

Nicaragua 9

Trinidad Tobago

El Salvador 15

1

Guatemala

Asia-Pacific

25

198 USA

Country

Number of Buildings

Latin America

Canada

North Amer.

23

Region

The process Figure 2 illustrates the general process from receiving client’s data to issuing ASCE 31-03 Tier 1 screening reports. The central element of the whole process was a SQLServer database, which was fed and updated with more and more data over the course of the project duration. Upon completion of each step in the process, the database was updated to reflect the current level of available information. The database provided the team with a live view of the current state of each building assessment. At completion of the information gathering phase, all of the required information was available and the project deliverable “Tier 1 Seismic Assessment Reports” of all buildings were generated from the database and made available to the client.

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Figure 2. Project Flowchart and key elements

Step 1: Desk Study – Information Gathering The portfolio holder provided a minimal amount of information with the list of buildings for Tier 1 evaluation. The process required, as a minimum, only the address of each building. Additional data such as building footage, stories or year built and project management specific information (e.g. contact person) was provided where available. Much of the information provided at this stage had no technical relevance for the evaluation itself. Even basic building data such as the number of stories was not always reliable and required adjustment by the site observation teams during the Tier 1 site visits. Steps 2: GIS Information The building addresses were processed through the Google Geocoder API and the resulting latitudes and longitudes were made available to the GIS (Geographic Information System) team, for verification. The GIS team provided the appropriate information for sites where the addresses provided were not standardised and in less developed regions where the building location could not be identified by address or street name. In this way the team was able to map all locations, which was very helpful for the project planning purposes such as travel arrangements, time estimates and optimising the site visit sequence in locations which are more remote relative to Arup offices. GIS location information was also used in the determination of seismic accelerations and site class data, where available from the United States Geological Service (USGS) website. Seismic accelerations were used to define the level of seismicity for each building location and for verification and rough stress check calculations. Utilising the database enabled the team to use batch inquiries and receive the data easily. Automated processes used by the GIS team mapped each location on a map and annotated it with short term accelerations SDS and one second accelerations SD1. Automated GIS processes also created individual seismicity figures for each building for later inclusion in the assessment report. Step 3: Geoseismic Information The USGS website provides seismic hazards for many locations worldwide, but does not necessarily cover all areas. Reports from the database helped to identify which locations were not covered and thus needed attention on an individual level. 4


Information for those sites not covered by the USGS, and by those sites that warranted extra attention due to available site or region specific data were handed over to the specialists of Arup’s geology team located in Australia. Desk studies were performed for these locations, which were mainly located in Central America, Asia and Australia. In addition to seismicity, they also determined which of the building sites are susceptible to liquefaction, slope failure and surface ruptures. Observations teams verified the risks by using region appropriate resources such as the website of California Governor’s Office of Emergency Services (Cal EMA). Defining the seismic parameters ahead of time led to significant time savings during the site visit period. All findings were input into the database so as to be available to the entire project team. Step 4: Site Observation Carrying out Steps 1 to 3 provided the necessary data required prior to the screening of the building. The teams were now set up and ready to perform the site visits. This step was the main focus of the work, since interaction with the client and presence at the building location was required. It is important to note that all of the other steps, although not equally apparent to the client, were just as important to achieve the project outcome and guarantee a smooth course of action. Teams of two engineers, equipped with iPad tablets and measurement devices (laser, tape or crack width guides), visited the sites and made the best effort to fill in the checklist and get as much information as possible about the building. A custom developed “ArupInspect - Seismic Evaluation” iPad application was used to record all findings. The application and all the features are described below. After each site visit the team uploaded checklist records from the application and the information was imported into the database. Precise planning and preparation as shown above pays back in efficiency and the teams were able to perform most site visits in less than two hours average (average building size: 1-2 stories, approx. 30005000ft2). Step 5: Reporting The creation of the final product, the building assessment report was automated as much as possible for standardisation. The database helped greatly to create assessment reports for all 385 buildings in an efficient and uniform way. One of the main project targets was to deliver all buildings reports, even though scattered all over the globe, in a consistent and uniform reporting style to satisfy the client’s expectations and standards. A common template was centrally developed from the project lead office in Los Angeles and was populated for each building using data from the database, automatically generated images and an appendix of all checklists. Only minor inputs were required from the observation team. After the reports were generated, inspecting teams added custom information such as building descriptions, extra photographs and information about special conditions found at the site and the availability of drawings at the facility. Drop down menus were used wherever the standardisation of response wording was of value to the client. Conclusions were added in a pre-formulated manner and gave the engineer the option to rate the building according to the following five category rating system. The choice to use some sort of rating system was much appreciated by the client. Even though this deviates from the typical screening outcome of “Tier 1 passed/not-passed” it gave us the possibility to add engineering judgment to the conclusion, use a standardised system and provide better service to the client. The five categories are shown and described in Table 2. While editing the report, it was possible for the engineer to revise checklist responses in this step. Reasons could be newly gained information about the building, findings on drawings if available or just adding results from quick shear calculations performed after the site visit. A link of the finished draft report was returned to the database.

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Table 2. Building Ratings and Conclusion statement Rating

1

2

3

4

5

Green

Findings and engineering judgment The Building meets the Tier 1 requirements, however it might have some non-structural deficiencies, which do not need engineering input to be resolved (e.g. restraint of tall narrow cabinets)

Yellow

Building is very likely to meet Tier 1 requirements, but not enough information for final conclusion are available (e.g. drawings are not available).

Orange

Building does not meet the Tier 1 requirements, but might still perform acceptable. No key deficiencies were identified (e.g. soft story, horizontal irregularity or insufficient diaphragms). Essentially not enough data was accessible to rate this building in another rating category

Red

Building does not meet the Tier 1 requirement and may perform unacceptable based on engineering judgement. Key deficiencies were identified (e.g. soft story, horizontal irregularity or insufficient diaphragms).

Black

Building does not meet the Tier 1 requirements and may have structural problems at a much lower level than the ASCE 31-03 major earthquake. Engineering judgment suggests an expedited Tier 2 assessment or exit plan for the building.

Conclusion statement (used in report) Further Tier-2 assessment is not recommended. …we believe that further evaluation using Tier 2 methods is likely to show that the structure is sufficient to achieve a life safety level of performance

Tier-2 assessment is required to reach any more conclusive opinions.

…we believe that further evaluation using Tier 2 methods is likely to show that the structure is not sufficient to achieve a life safety level of performance …we believe that further evaluation using Tier 2 or Tier 3 methods is highly likely to show that the structure is not sufficient to achieve a life safety level of performance…

Step 6: Quality Process An internal QA process was used to ensure that each report was reviewed and to verify the quality of all reports to be presented to the client. The process included an automated review to check for discrepancies that would not be easy to pick out to a human reviewer. The review script checked for discrepancies, updated the database for revisions made during the report writing process and imported the colour rating to the database. Furthermore, reviews checked to make sure that all checklist items had been answered. A missing response triggered an error message and the draft report was pushed back to the responsible engineer. Reports which had passed the scripted review were pushed to project lead engineers as the final step in the QA process. Step 7: Issue of Report The Tier 1 Seismic Assessment Report is released to the client. If a building was rated green and passed the Tier 1 screening, it is still possible that nonstructural deficiencies were found. The conclusion in this case included recommendations to fix all non-structural deficiencies in order to enhance the seismic performance of that location and achieve the required Life Safety performance. Parallel to assessment reports for each building regional and global summary reports were issued, showing building overviews, statistics of building types and common deficiencies to help the client understand the main risks without studying each building report. Arup conducted a code research for each country to indicate the seismic code development. This again helped to put findings in context to the local building industry and to demonstrate what to expect from buildings built in certain years. The central database and the iPad application can be identified as the two key elements leading to optimisation of the process.

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ASCE 31-03 Tier 1 Screening iPad application A Seismic evaluation iPad application was developed within Arup to replace the old fashion practice using paper and pen in the field, circling responses on the checklists copied from the code book. Even though the app development was a major upfront effort the return in time saving and efficiency was enormous. Of course, the application needed to feature all ASCE 31-03 Tier 1 checklists and an automated selection of checklist, based on level of seismicity and the building type. Information from the database was used to create building specific input files as starting points for the inspection teams. This eliminated the need for manual input of building specific data such as location, address and seismicity as it was imported to the app, but allowed for editing in the event that conditions were found to differ from what was expected. Inclusions in the design of the app were aimed to provide all possible information to the site team and relieve them from carrying the code book around with them. A neat and very useful feature proved to be the inclusion of code explanations to the typical checklist questions. The explanation statements were taken from chapter 4 of ASCE 31-03 Tier 2 as typically each Tier 1 checklist item refers to a description in the Tier 2 procedure. Observation photos and/or comments could be added to all checklist items. It was possible to add mark ups to photos or provide a sketch rather than using a photo. The main benefit of this was that the app exported data and photographs for import into the database, enabling post processing and editing of all collected data. Photographs added to a checklist item were automatically added to the report in the appropriate location. A simple PDF report output created directly by the app was considered during the development but it would not have provided any of the advantageous possibilities presented by direct data export. Direct export and database uploading features also provided the potential for responsible and automatic data backup. This was considered beneficial especially in faraway locations, where it would be difficult and costly to go back to repeat the site visit in case of data loss due to mobile device damage, stolen devices or similar situations. Database as the central element The process diagram in Figure 2 clearly shows the database as the central element or hub of the entire process. Each step leads to an increase in data amount and quality. Using a fully featured database has several advantages over using spreadsheet software such as Microsoft Excel when dealing with a large amount of data, particularly when that data requires collaboration among many users. As well as providing data management, data querying, multiuser availability and access control, the database for this project was set up to mimic a versioncontrol system. Data records are superseded rather than deleted, allowing for instant access to the version history of each building’s data and providing the ability to revert back to previous values when appropriate. The process of importing and exporting the data is not further described in this paper, instead it will be shown how the data was used to post processed for visualisation and statistics. The latter were very helpful for consultation with the client for future phases of the project. Visualisation and Analysis of Evaluation Data Since the building colour rating was imported into the database (see step 6), it was possible to develop a scatter diagram, which essentially summarizes the rating, but also presents additional information to the upper facility management to base their prioritisation on. There were essentially two versions of this diagram, the printed version as shown in Figure 3 and also an interactive version. The interactive version would look exactly the same if printed but, as a live document, additional data such as building identification number and location are displayed by pop-up when the user hovers the mouse over a data point. This feature can be easily modified or enhanced to show any data available in the database and creates multidimensional diagrams which are easy to interpret.

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Figure 3. Summary of Building rating, Seismic Hazard and Building size

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In Figure 3, the y-axis presents the Intensity of Hazard given as the short term acceleration SDS and the buildings are sorted by region and displayed along the x-axis. The colour of each data point reflects the building rating, the data point size represents the seat count number or, in other words, the number of employees located in this building. The diagram can easily be adjusted and resorted as required; for example, showing only buildings located in the USA might be useful to gain a better regional view. The deliverable of 385 building reports, each between 20 and 50 pages, presented a good reference for the individual facility manager for each building structure. However, from a broader view, on a regional or global basis, it was not possible for the client’s upper management to be familiar with all reports. While the data base was a powerful tool to manage all data during the project phase, it also qualified as a perfect resource for post processing the findings and analysing a building portfolio. Analysis results and data visualisation was used to support the management in understanding and interpreting the ASCE 31-03 Tier 1 outcome and eventually enabled them to prioritise buildings recommended for Tier 2 or Tier 3 evaluations. There are many tools available for preparing presentation graphics, of which Microsoft Excel seems to be the most commonly known and used. Having all of the project data available in the database made it a simple matter to export it to an Excel format for use in creating presentation graphics. It is important to note that the main component enabling us to produce and present global results was not Excel, but the diligently updated and maintained database. A second very useful data representation was provided showing the vulnerability of certain building types and thus the urgency of more detailed assessments. This was quite powerful and useful, particularly when buildings were filtered by region or country. As different regions and countries undergo code changes on unique time scales, the data generally only shows trends when split up into appropriate groups. For example, the City of Los Angeles classifies concrete moment frames buildings built prior to 1980 to be at risk. This is based on a code requirement for ductile design of moment frames implemented in the Uniform Building Code in 1976. This change was the result of damage observed after a local earthquake in 1971 and would likely not have made it into the codes of other countries in the same year. Table 4 shows exactly this example, where buildings are shown by building type, stories and year built pre/post 1980. The buildings marked in red were identified as high risk buildings and suggested for prioritised further evaluation.

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Table 4. Building Type Year and Stories at US West Coast

pre 1980 Number of Stories Concrete C1 C2 C2A C3A Masonry RM1 RM1-RM2 RM1-W2 RM2 Other Unknown PC1 Steel S1 S1A S4 S5A Unreinforced Masonry URM Wood W2 Grand Total

1 4 1 2 1 41 38 1 2 3 2 1 5 3

2 9 2 1 6

3 2

10 6 1

1 1

1 1

3 1 1 4

2

2 1 1

1 1 20 20 74

4 4 13 13 41

4 1

5 1 1

6

7 1 1

1

post 1980 8 1

9 1

1

1

10 1 1

12 3 2 1

Potential Non-Ductile Concrete Buildings 2

2

2 2

1

2 2

1

2 2 7

4

1

2

1

1

1

1

3

Total 24 8 6 9 1 54 45 1 1 7 4 2 2 14 4 5 2 3

1 1

Total 1

1

1

4 4

4 4

1

1

1

1

5 5 35 35 136

1 1 8 8 15

1 1 8 8 15

Conclusion and further work Maintaining a database can provide great value to the team if used correctly, making a positive impact on data analysis, team efficiency, accuracy and presentation. The effort that would have been required to produce these results and diagrams based only on the reading of hundreds of individual, and possibly highly disparate building reports, would have been enormous. REFERENCES

American Society of Civil Engineers (2003) ASCE 31-03 Seismic Evaluation of Existing Buildings, American Society of Civil Engineers, USA American Society of Civil Engineers (2014) ASCE 41-13 Seismic Evaluation and Retrofit of Existing Buildings, American Society of Civil Engineers, USA Mayoral Seismic Safety Task Force (2014) Resiliency by Design, City of Los Angeles, USA San Francisco Department of Building Inspection (2013) Mandatory Soft Story Retrofit Program, Ordinance No 66-13, City of San Francisco, USA International Conference of Building Officials (1976) Uniform Building Code 1976 Edition, Whittier, USA

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