It is one of the unknown parameters in battle , the designing value of prestressing force and enormous difference between actual value may influence the service function , will even cause the incident .

• 在役预应力混凝土桥梁有效预应力本身就是未知参数之一,预应力设计值和实际值之间的巨大差异可能会影响服务功能,甚至会导致安全事故。