Wind Load Effects on Manufactured Home Foundations

Abstract

Problem statement: Manufactured homes are susceptible to hurricane damage. Each year, significant losses, in terms of fatalities and property damage, are reported. There is always a prevalent concern about lateral load resistance capacity of tie-down system of manufactured homes when subjected to windstorms. This study is performed to determine the effects of hurricane wind on manufactured homes’ foundations. Approach: A 1:120th scale model of single wide manufactured home of size 14 ft by 80 ft was designed for the wind tunnel test. Proper instrumentations and simulations were considered to measure wind forces applied on the model. Sting balance and Pitot static tube were used to measure forces and air velocity during the wind tunnel test. Displacements of anchors were observed during the test. Results: The ultimate forces as well as the displacements of the anchors were determined at different angles of wind direction ranging from 30-180°. Wind speed inside the tunnel was increased at the rate of 5 miles h^-1. Conclusion/Recommendations: Test result showed that auger anchors used to support lateral load are incapable to resist hurricane wind loads. It was found that anchors displaced 2 in. vertically and 4 in. horizontally at loads less than 4725lb. Tested manufactured homes anchors experienced maximum force of 4087 lb when 45 miles h^-1 wind acted in transverse direction to the wall. The manufactured home anchors displaced more than 2 inches in vertical direction and 4 inches in horizontal direction due to this wind load. This research indicated that manufactured homes ground anchors can sustain wind velocity of 95 miles h^-1 when the wind is acting at longitudinal direction.