A　typical　failure　of　the　light　framed　arch　bridge　under　frequently　super　loads　is　studied,　by　means　of　establishing　the　EFM　solid　models　for　the　whole　bridge　and　the　bracing　strut　to　analyze　the　failure　mechanism　of　the　bracing　strut　in　the　Pingzhai　framed　arch　bridge　from　the　mechanical　behavior　and　some　defect　of　the　structure　itself,　simulating　the　deterioration　of　reinforced　concrete　in　wet　joint　of　the　bracing　strut.　Based　on　the　mechanics,　a　new　practical　method　for　restoring　and　reinforcing　the　above　bracing　strut　is　presented　also,　which　has　been　proved　to　be　successful　in　the　engineering　practice.