NBSIR 74-567 FY 74 Progress Report on Design Criteria and IMetliodology for Construction of Low-Rise Buildings to Resist Typhoons and Hurricanes N. J. Raufaste, Jr. and R. D. Marshall Center for Building Technology Institute for Applied Technology National Bureau of Standards Washington, D. C. 20234 July 1,1974 Interim (July 1, 1973 through June 30, 1974) Prepared for The Office of Science and Technology Agency for International Development Department of State Washington, D. C. 20523 Under a Participating Agency Service Agreement (PASA) No. TA(CE) 04-73 NBSIR 74-567 FY 74 PROGRESS REPORT ON DESIGN CRITERIA AND METHODOLOGY FOR CONSTRUCTION OF LOW-RISE BUILDINGS TO RESIST TYPHOONS AND HURRICANES N. J. Raufaste, Jr. and R. D. Marshall Center ^or Building Technology Institute for Applied Technology National Bureau of Standards Washington, D. C. 20234 July 1, 1974 Interim (July 1, 1973 through June 30, 1974) Prepared for The Office of Science and Technology Agency for International Development Department of State Washington, D. C. 20523 Under a Participating Agency Service Agreement (PASA) No. TA(CE) 04-73 M. U. S. DEPARTMENT OF COMMERCE, Frederick B. Dent, Secretary NATIONAL BUREAU OF STANDARDS, Richard W. Roberts, Director CONTENTS TABLE OF FIGURES 11 SI CONVERSION FACTORS. ' iv ABSTRACT v INTRODUCTION 1 A. SUMMARY OF PROGRESS FOR FISCAL YEAR 1974 4 ^ Background Information. Wind Research Activities 6 Field Test Sites 6 Research Equipment 11 Wind Tunnel Modeling 14 Collection, Reduction and Analysis of Field Data .... 21 Assessment, Selection and Application of Cllmatological Data 25 International Workshop on Effects of Extreme Winds 25 Library Research 26 Information Transfer to Other Wind Areas 26 Soclo-Economic and Housing Study 27 Philippine Housing Construction Practices 29 B. EXPECTED PROGRESS THROUGH PROJECT COMPLETION 39 Full-Scale Studies 39 Wind Tunnel Studies 39 Development of Design Pressure Coefficients 39 Soclo-Economic Analysis 40 Computer-Generated Motion Picture Film 40 Regional Conferences 40 C. FISCAL YEAR 1975 PROJECT SCHEDULE 41 APPENDIX A: Minutes of the 1st - 6th Philippine Advisory Committee Meetings A-1 APPENDIX B: "Simulations of Atmospheric Flows in Short Wind Tunnel Test Section" B-1 APPENDIX C: Bibliography of Wind Related Documents C-1 APPENDIX D: Housing and Wind Problems in the Northern Caribbean and Indian Ocean Countries D-1 APPENDIX E: Housing in Extreme Winds E-1 i TABLE OF FIGURES Figure Page 1 Building test sites 8 2 Wind research equipment undergoing final inspection by NBS team member prior to shipment to the Philippines by the ' USAF Military Airlift Command 9 3 The first (bottom) and second (top) test houses were ; instrumented for winds in September and November respectively, s ^ Note the pressure transducers (round disks) located on the corrugated iron roofs; others are fastened on the walls 10, 4. Aerial view of instrumented test building at Daet Weather Station 12 5 ^ Typical installation of ground anchors by PAGASA technicians prior to erection of meterological tower ' 15 iS PAGASA technicians assembling tower section 16 ,7 Erecting 10-meter meteorological tower which supports the anemometer and ambient pressure probe. Note guy wires running to ground anchors 17 :8 Of f icer-in-charge at Daet Station receiving instructions on assembly of pressure transducer from member of PAGASA Headquarters staff 18 9 Typical installation of pressure transducers and signal cables on a test building roof .19 10 Installed pressure transducers on a test building at Laoag City 20 11 Member of NBS research team instructing staff of the National Center for Hydraulic Research (at the UP) in the operation of wind tunnel test equipment 22 12 Photograph of 1:80 scale model of field test house installed in UP wind tunnel. This is a view looking upstream. Note ball point pen for scale 23 ii TABLE OF FIGURES (Contd.) Figure Page 13 Shallow trench for wall placement 30 14 Wall construction quality and window framing details 30 15 Wall pier and roof bearing detail 32 16 Corner column reinforcement 32 17 Column reinforcement anchorage to roof rafters 33 18 Completed column and roof anchorage 33 19 Roof anchorage detail 34 20 Detail of corner column and exterior wall 34 21 Window framing detail 35 22 Exterior appearance of completed structure 35 | 23 Roof to truss anchorage detail 37 ' 24 Wall damage resulting from Typhoon Yoling, November 1970 38 25 Wall and roof damage resulting from Typhoon Yoling, November 1970 38 I iii . SI CONVERSION FACTORS This report describes measurements in metric units. It is recommended that the reader assume the responsibility for applying the appropriate conversion to English units. The United States of America, as a signatory to the General Conference of Weights and Measures (which gave official status to the metric SI system of units) , recognizes the International Standard (SI) unit of measurement Length 1 centimeter (cm) = 0.394 inch (in) 1 meter (m) = 3.281 feet (ft) 1 kilometer (km) = 0.622 mile (mi) Velocity 1 centimeter per second (cm/s) = 0.394 inch per second (in/s) 1 meter per second (m/s) = 3.281 feet per second (ft/s) IV ABSTRACT This report presents the major accomplishments of the second phase of a three year project to provide engineering and technical assistance to the Agency for International Development (AID) , Department of State in developing improved design criteria for low-rise buildings to better resist extreme winds. During Fiscal Year 1974, project staff members of the Center for Building Technology, National Bureau of Standards, Washingt D. C. 20234 commenced several tasks. These tasks will serve as major inputs to the development of improved design criteria. The principal tasks included: 1) selecting a second and third field test site in the Philippines, 2) instrumenting four full-scale houses at the sites, 3) instrumenting the University of Philippines wind tunnel facility, 4) helping arrange and participating in an international workshop at Manila during November 1973, and 5) developing in conjunction with short-term consultants in Bangladesh and Jamaica a methodology for the transfer of the technology to those areas. v . INTRODUCTION The National Bureau of Standards (NBS) through this project is developing improved design criteria for low-rise buildings in developing countries to better resist the effects of extreme winds. The project is sponsored by the Agency for International Development (AID) under Participating Agency Service Agreement (PASA) No. TA(CE) 04-73 with funding under AID's central research program. The overall management is provided by William H. Littlewood, Associate Director, Office of Science and Technology, AID. This research project originated from recognition of a need for additional research to supplement the limited amount of existing data regarding the wind effects on low-rise buildings, especially in developing countries. The existing criteria for wind loads in developed countries do not make provisions for steady and fluctuating wind pressures along the edges of roofs and walls where flow separation occur. Yet wind flows along these regions are one of the primary contributors to building damages. This research and the resultant development of suitable design criteria and methodologies will provide high benefits in reducing losses of structures and lives in the countries where the criteria are applied. The Philippines experience the highest worldwide annual frequency and intensity of tropical storms. Within the Philippines, the frequency of tropical storms is greatest in Luzon. Statistics indicate that between 1948 and 1971 the Philippines were exposed to 482 tropical storms, or an average of 20 per year. As such, these occurrences make the Philippines a natural laboratory to measure wind loads on buildings. The Philippines, consisting of over 7,100 islands, are located approximately 800 kilometers off the coast of southeast Asia. The archipelago extends north and south for approximately 1600 kilometers at its widest part. The Philippines are generally divided into three regions: Luzon, the northern section: the Visayas, Palawan and Mindoro, the central section; and Mindanao and the Sulus, the southern section. Approximately 37 percent of the land area is included within Luzon, 29 percent in the Visayas area and 34 percent in Mindanao. There are about 90 different dialects spoken among the Philippine population of over 37 million people. NBS's extreme wind study includes several components. It is based largely on field work (collection of wind loading data from seven field test buildings) and from wind tunnel testing of building scale models. The study also includes a review of climatological data from the weather bureaus of the Philippines and two other developing countries, Bangladesh and Jamaica. Socio-economic, architectural and structural data, and codes and standards information from the Philippines and other developing countries will be included in the implementation aspects of this study. In addition, knowledge about wind effects on buildings obtained in other countries such as the United States, Japan. Australia and the United Kingdom will be used as required. "Climatology and Wind Related Problems in Philippines" by R. L. Kintanar, November 1973, Manila, Philippines (Paper presented at a workshop in Manila, Philippines) , . , The following Fiscal Year 1974 Project Status Report discusses the principal activities and accomplishments during the period July 1, 1973 through June 30, 1974. Also included is a summary