Hualien's Gaoliao Bridge sustained extensive damage in the 918 earthquake. A research team from National Chung Hsing University took aerial photos of the scene using a drone and then used high-speed computer image processing technology to create a 3D model for the government and civic groups to use for disaster survey and reconstruction work.
The bridge's beams and columns have broken apart, exposing steel reinforcing bars. Meanwhile, the bridge deck collapsed onto the riverbed. This is Hualien's Gaoliao Bridge, which was at the epicenter of the 918 earthquake and sustained extensive damage.
Yang Ming-der, Distinguished Professor, Dept. of Civil Engineering, NCHU: “To help with disaster relief, we produced this 3D model just one hour after getting the aerial images.”
In the past, 3D imaging technology was used in the survey of major disasters. It wasn't easy and also risky to investigate the bridge's damage at the scene, so a National Chung Hsing University research team used a drone to capture high-res images on Sept. 19 and image processing technology to create a 3D model. This model shows what kind of damage the bridge sustained and where. The team also set up a website to provide this information for free for use in disaster survey and reconstruction work.
Yu Chih-peng, Dep. Chair, Dept. of Civil Engineering, NCHU: “You can see everything all at once. If you go to the scene, you'll only be able to stand on certain parts to see. This thing offers the opportunity for a comprehensive view.”
The Hualien County Government has so far determined that six bridges were damaged by the earthquake, including Gaoliao Bridge. Two suffered severe damage and will need to be rebuilt. Three others need repairs. The total cost is estimated at NT$3 billion and the county government has applied to the central government for funds.
Teng Tzu-yu, Director, Economic Affairs Dept., Hualien County: “If they're going to be rebuilt, they'll have to conform to the length and height in the existing river management plan. The bridge width also needs to conform to current highway design standards.”
The county government said new bridge designs must be thoroughly evaluated, but it's hard to predict how long the construction will take. It has asked residents to make detours in the meantime and will do its best to accelerate the reconstruction work.