预应力简支T梁有效预应力评估研究

【作者】 缪伟；

【导师】 宋一凡； 刘龄嘉；

【作者基本信息】 长安大学 ， 桥梁与隧道工程， 2005， 硕士

【摘要】 预应力混凝土结构在中小跨径公路桥梁占有主导地位。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。因此预应力混凝土结构中有效预应力的测试评估就显得尤为必要。 本文研究作为2003年陕西省交通科技项目“在役混凝土桥梁结构永存预应力及安全性评价研究”的一部分。其目的就是通过模型试验系统分析研究预应力混凝土结构的应变、挠度、自振频率与预应力变化之间的关系,探索预应力有效值的预测方法。 在役混凝土桥梁有效预应力与结构本身的一些结构力学参数有着一定的联系,如结构的固有振动频率、挠度、混凝土的应变、普通钢筋的应变等。 本文针对在役混凝土梁桥,结合试验条件按全预应力构件设计了两片模型试验T梁,预应力布束按常用的曲线布置形式。对模型试验梁在不同预应力等级下施加全预应力状态下的设计最大荷载值,进行静、动力试验通过自振频率、挠度、应变等有关数据。分析给出T梁自振频率随预应力变化规律,并通过试验实测应变不同弹性模量取值条件下,由钢筋、混凝土应变估计有效预应力,并对不同的有效预应力与实测张拉锚固预应力进行对比分析,给出接近实际预应力的修正系数。 本文研究可为探索永存预应力与相关力学行为参数之间的内在规律,对在役预应力混凝土梁桥的结构性能评定奠定基础。更多还原

【Abstract】 Prestressing force concrete in step highway-bridge of the foot-path occupy leading status while being medium and small structure. 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 . The test of prestressing force seem particularly essential when being assessed that so Effective in the concrete structure of prestressing forceThis text as 2003 Shaanxi Province traffic scientific and technological project a part on " concrete bridge structure perpetuity prestressing force and security appraisal study in battle " research. Its purpose is to analyse and research through the model pilot system: Emergency , deflection , relation of natural frequency and prestressing force while changing by oneself of the concrete structure of prestressing force, explore the virtual value prediction method of prestressing force. Have certain contacts with some structural mechanics parameters of structure in the concrete bridge perpetuity prestressing force of the battle , for instance emergency of the emergency of the inherent vibration frequency of the structure , deflection , concrete , ordinary reinforcing bar ,etc.To in battle concrete beam bridge , combine experimental condition design two scenes of model test T roof beams according to the whole prestressing force component this text, cloth bunch of prestressing force is assigned the form according to commonly used curve. Exert the greatest loading value of design under the whole prestressing force state to the roof beam of model test under the grade of different prestressing force, carry on the quiet , motive force test through relevant data of natural frequency , deflection , meeting an emergency by oneself etc.. Is it provide T roof beam natural frequency vary with prestressing force law , is it meet an emergency different elastic modulus terms of fetching etc. to survey through test to analyse, is it estimate effective prestressing force to meet an emergency by reinforcing bar , concrete, and to different effective prestressing force with survey piece draw firm prestressing force of the anchor compare and analyse, provide the revision coefficient of prestressing force.This text studies in order to explore the inherent law between perpetuity prestressing force and relevant mechanics behavior parameter, evaluate the foundation of establishing on the structure performance in the prestressing force concrete beam bridge of the battle..更多还原