格构木梁加固方法的研究  

Study on the Strengthening Methods of Lattice Timber Beams

作　　者：朱雷[1] 许清风[2] 陈建飞[3] 

机构地区：[1]上海建科院上海市工程结构新技术重点实验室,上海200032 [2]东南大学城市与建筑遗产保护教育部重点实验室,南京210096 [3]爱丁堡大学工程学院,英国爱丁堡EH93JL

出　　处：《四川大学学报（工程科学版）》2012年第1期28-35,共8页Journal of Sichuan University (Engineering Science Edition)

基　　金：东南大学城市与建筑遗产保护教育部重点实验室开放课题(KLUAHC1009);国家“十一五”科技支撑计划资助项目(2006BAJ03A10-02)

摘　　要：进行了10根木梁的对比试验研究,其中3根为对比普通木梁,3根为未加固格构木梁,4根为加固格构木梁。研究结果表明:未加固格构木梁的受弯承载力和初始弯曲刚度较普通木梁均略有降低;底面粘贴1层碳纤维(CFRP)布加固格构木梁的受弯承载力较未加固格构木梁显著提高54%,初始弯曲刚度提高34%,极限位移显著提高63%。空隙处采用结构胶或灌浆料填充的格构木梁的受弯承载力平均提高30%,初始弯曲刚度显著提高195%,极限位移则显著降低54%。结构胶填充并在梁底面粘贴1层CFRP布的加固格构木梁受弯承载力显著提高92%,初始弯曲刚度显著提高251%,极限位移则降低48%。未加固格构木梁和粘贴1层CFRP布加固格构木梁的受拉肢和受压肢跨中应变变化分别保持平截面假定;其受压肢和受拉肢均为下侧受拉上侧受压,中间木垫块基本不受力。空隙采用结构胶填充的加固格构木梁跨中全截面应变变化基本保持平截面假定;其受压肢受压,受拉肢受拉,中间木垫块亦参与全截面受力。研究表明:在格构木梁空隙处填充灌浆料或结构胶可显著提高其初始弯曲刚度,但对提高承载力不显著;在格构木梁底面粘贴CFRP布可显著提高其承载力,但对提高初始弯曲刚度不明显。格构木梁有限元数值模拟结果可满足工程应用的精度要求。Ten timber beams were tested,including three reference normal beams,three unstrengthened lattice beams with different configurations,and four lattice beams strengthened by different methods.The test results showed that the ultimate flexural strength and initial flexural stiffness of unstrengthened lattice timber beams are lower than the reference normal beams.Compared with the unstrengthened lattice beam,the ultimate flexural strength,initial flexural stiffness and mid-span displacement at the ultimate state increase by 54%,34% and 63%,respectively,for the beam bonded with a CFRP sheet to the tension face,30%,195% and-54%,respectively,for beams with their spaces at the middle filled with structural adhesive or cement grouting,and 92%,251% and-48%,respectively,for the beam strengthened with both structural adhesive filling and a CFRP sheet bonded to its tension face.The strain distributions in the upper and lower legs are nearly linear through their respective depth at middle-span during the whole loading process for both unstrengthened lattice and CFRP-strengthened lattice beams but the plane section assumption is not satisfied as a whole.For beams strengthened with structural adhesive or cement grouting fillings,the strain distributions along the entire height at middle-span are nearly linear during the whole loading process so a plan section remains almost plan.This study showed that external bonding of CFRP sheets is an effective method for enhancing the ultimate strength and filling with structural adhesive is an effective way for increasing the initial flexural stiffness.The finite element analysis results of lattice timber beams can completely satisfy the engineering precision requirement.

关 键 词：格构木梁 加固方法 受弯承载力 刚度 碳纤维布 填充 

分 类 号：TU366.1[建筑科学—结构工程]