Estimation of Fatigue Life of Long-Span Bridge by Considering Vehicle-Bridge Coupled Vibration
To estimate the fatigue life of long-span steel bridge more accurately, this paper proposes a method for estimating the fatigue life of long-span bridges by considering vehicle-bridge coupled vibration. Firstly, the universal equation of vehicle-bridge vibration is derived based on triaxial standard multi-scale model of fatigue vehicle and bridge, and relevant program for vehicle-bridge coupled vibration is programmed. Secondly, a method for estimating the fatigue life of long-span steel bridge is proposed based on fracture mechanics theories, and the analysis process is expounded in details. Finally, the method for estimating fatigue life proposed in this paper is verified by taking a double pylon cable- stayed bridge with orthotropic steel bridge deck slab as an example.
Fatigue
AJN ▼ April 2001 ▼ Supplement 31 D id you know that the primary complaint of people with cancer is fatigue? In a recent study conducted by the Fatigue Coalition, of 379 patients interviewed, 76% reported they experienced fatigue, 54% reported nausea, 23% depression, and 20% pain. In a previous study, 78% of patients reported fatigue during the course of their disease and treatment, with 32% reporting they experienced it daily.
Contractor Failure: Analysis
The possibility exists for any construction contractor to fail to filfill the contract requirements associated with a facility. Contractor failure occurs when a contractor is unable to perform his/her contractual duties, thus requiring the facility owner to invoke the contract's nonperformance clause. This paper provides aggregate contractor business failure statistics and outlines potential causes for failure. A framework to identify and quantify the associated costs is also introduced. Several case studies are presented to examine the cause and cost of failure and the means by which the facilities were completed. Alternatives available for project completion when contractor failure occurs are discussed. Recommendations to identify and monitor contractors at high risk for failure are outlined as well. This paper provides facility owners with a greater awareness of the possibility of contractor failure, how to quantify costs of contractor failure, and avoidance techniques.