【作者】 李翔；

【导师】 曹双寅； 徐志纯；

【作者基本信息】 东南大学 ， 建筑与土木工程（专业学位）， 2021， 硕士

【摘要】 在我国逐步步入社会主义现代化的过程中,交通的发展也愈发繁荣,交通车辆数量与日俱增,尤其是在人口密集区,不仅建筑群密集,同时车流量大,建筑受到临近的交通振动影响更加显著。交通荷载可能使得结构某些部位长期处于振动状态下,结构承载力下降,出现疲劳损伤。其中砌体结构作为我国传统的建筑结构之一,其应用十分广泛,在我国既有建筑中所占比例超过半数,由于砌体结构整体性较差,受交通振动作用下易发生疲劳损伤,因此本文主要采用数值模拟方式对其进行振动分析,以得出振动控制建议。本文论述了交通振动下结构动力学模型的建立方法,对砌体结构在交通振动作用下的动力响应进行了相关分析,主要工作及成果如下:(1)砌体结构振动疲劳分析流程的建立。本文整理了既有砌体结构疲劳分析方法、疲劳控制标准,形成砌体结构疲劳分析通用流程。同时从振动的“产生-传播-响应”三个阶段分析振动影响因素,为后续影响参数分析奠定基础。(2)砌体结构动力学模型的建立。选用车辆荷载模型,确定结构动力响应建模分析方法。以南京龙脖子路段城墙作为算例进行建模分析,提取其在车辆荷载作用下的振速响应对比实测数据,验证了建模方法的合理性。(3)振动相关参数影响规律分析。针对车辆行驶速度、车辆自重、车辆行驶路线、振源距离、土体性质、砌体结构层数的不同分别建模并提取振动速度、振动应力对比分析。结果表明,车速增加引起的结构振动响应增加是非线性的;车辆自重与振动速度、应力的变化是线性正相关的;双线同向行驶车辆造成振动比单线及双线对向行驶造成振动大;振源距离越远,土体弹性模量越大,结构振速、振动应力越小;而砌体结构层数的增加会造成结构振动速度减小,但对结构应力而言并无明显变化规律。(4)根据砌体结构疲劳寿命曲线,分析了砌体结构在重力及交通动荷载作用下的应力情况,根据疲劳控制标准给出了既有砌体结构的振动控制建议,即结构在静载作用下主压应力超过0.8MPa时,结构底部边界处与地面接触部位振动速度不能超过1mm/s。(5)实例分析。以南京挹江门城墙作为工程实例,对其进行建模分析,研究了车辆下穿城墙时的振动响应变化,依照振动控制建议评估其疲劳寿命,得出其不会发生疲劳损伤。更多还原

【Abstract】 In the process of my country’s gradual progress in socialist modernization,the development of transportation has become more prosperous,and the number of transportation vehicles has increased day by day,especially in densely populated areas.Not only are buildings densely populated,but the traffic volume is large,and buildings are more affected by nearby traffic vibrations.Significantly.The traffic load may cause some parts of the structure to be in a state of vibration for a long time,the bearing capacity of the structure decreases,and fatigue damage occurs.Among them,masonry structure is one of the traditional building structures in our country,and its application is very wide.It accounts for more than half of the existing buildings in our country.Due to the poor integrity of the masonry structure,it is prone to fatigue damage under the action of traffic vibration.This dissertation mainly uses numerical simulation to analyze its vibration in order to obtain vibration control suggestions.This dissertation discusses the establishment method of structural dynamic model under traffic vibration,and related analysis of the dynamic response of masonry structure under traffic vibration.The main work and results are as follows:(1)The establishment of a vibration fatigue analysis process for masonry structures.This dissertation sorts out the fatigue analysis methods and fatigue control standards of existing masonry structures,and forms a general process for fatigue analysis of masonry structures.At the same time,the vibration influencing factors are analyzed from the three stages of vibration "generation-propagation-response",which lays the foundation for subsequent analysis of influencing parameters.(2)Establishment of dynamic model of masonry structure.Select the vehicle load model to determine the structural dynamic response modeling analysis method.Taking the city wall in Longneck section of Nanjing as an example for modeling analysis,the vibration velocity response under vehicle load is extracted and the measured data is compared to verify the rationality of the modeling method.(3)Analysis of the influence law of vibration-related parameters.According to the difference of vehicle speed,vehicle weight,vehicle route,vibration source distance,soil properties,and the number of masonry structure layers,models are modeled and the vibration speed and vibration stress are compared and analyzed.The results show that the increase in structural vibration response caused by the increase in vehicle speed is non-linear;the weight of the vehicle is linearly positively correlated with the changes in vibration speed and stress;the vibration caused by two-lane vehicles driving in the same direction is greater than that caused by single-line and dual-line driving in opposite directions;The greater the distance from the vibration source,the greater the elastic modulus of the soil,and the smaller the structural vibration velocity and vibration stress;while the increase in the number of masonry structures will cause the structural vibration velocity to decrease,but there is no obvious change in structural stress..(4)According to the fatigue life curve of the masonry structure,the stress situation of the masonry structure under the action of gravity and traffic dynamic load is analyzed.According to the fatigue control standard,the vibration control suggestion of the existing masonry structure is given,that is,the structure is under static load.When the principal compressive stress exceeds0.8 MPa,the vibration velocity of the part in contact with the ground at the bottom boundary of the structure cannot exceed 1 mm/s.(5)Case analysis.Taking Nanjing’s Yijiangmen city wall as an engineering example,modeling and analyzing it,studying the vibration response changes when vehicles pass through the city wall,and assessing its fatigue life according to vibration control recommendations,and it is concluded that it will not suffer from fatigue damage.更多还原