The M41 mark 921 Jiji earthquake has caused considerable loss of life and property in central Taiwan. For the bridge structures that have been completed and opened to traffic in the central section of the National Highway, the Ministry of Communications has strengthened the bridge with the latest seismic design specifications. Project scope: National Highway 4 Fengyuan Viaduct 9K+819~16K+545 (A1~P174), the construction scope is about 6.7 kilometers in length. It needs to be reinforced with foundation reinforcement and upper structure anti-drop device reinforcement. There are 222 foundation reinforcements and additional 2 anti-shock concrete blocks, 318 sets of steel plate anti-shock devices, 10 sets of anti-falling devices, and 10 sets of anti-vibration braces. Expected goal: To make the National Highway bridges meet the latest bridge seismic standards and achieve the goal of sustainable development of the country's overall disaster prevention, and to minimize the damage in the event of a major earthquake.