悬索桥主缆与索鞍间侧向力及摩擦滑移特性分析

发布时间：2018-06-10 16:14

本文选题：主缆抗滑 + 精细化模型　；参考：《西南交通大学》2017年硕士论文

【摘要】：多塔连跨悬索桥作为跨越宽广水域的重要桥梁结构形式,计算理论与施工技术的不完善成为限制其发展的重要因素。其中"中塔效应"的存在,即主缆抗滑移安全与挠跨比之间存在的对立关系,是多塔悬索桥设计必须解决的矛盾之一。目前关于主缆抗滑的计算参数仅局限于结构的总体布置及荷载形式,实际工程中则多采用模型试验的方法提取名义摩擦系数,而针对鞍槽内索股的真实滑移情况及传力机理分析,则需要建立主缆-索鞍精细化接触模型进行研究。本文主要通过以下三个方面对主缆-索鞍抗滑问题展开了讨论:(1)基于ABAQUS/Explicit平台对主缆-索鞍体系进行局部精细化建模,准确设置钢丝与钢丝、钢丝与鞍槽之间的接触摩擦关系,计算分析了单槽内一定数量钢丝排布的侧向力分布模式,并探讨了索股排列方式、索股张力及构件之间的摩擦系数对侧向力分布的影响。(2)基于ABAQUS/Explicit平台对主缆-索鞍体系进行全结构精细化建模,代入相同条件下的侧向力换算结果,模拟对应的分层滑移状态,计算研究滑移过程中索股张拉端的位移形式、索股两端应力变化及钢丝沿索长纵向的应力分布模式,从细观层面对分层滑移特征及传力机理进行分析。(3)针对主缆索鞍抗滑移的问题,探讨了鞍槽内索股排列方式、索股张力及构件之间的摩擦系数对抗滑能力的影响,并分析评估了设置竖向摩擦板或水平摩擦板对提高抗滑能力的作用效果。论文得出如下主要结论:索股侧向力呈负指数收敛型曲线分布,且在钢丝底层出现骤减现象;侧向力是导致分层滑移的直接因素;分层滑移的现象可归结为:上层钢丝先于下层钢丝滑移、同一奇数层钢丝则中间钢丝先于外侧钢丝滑移、当底层钢丝出现极限滑移,则索股发生整体滑移;竖向摩擦板与水平摩擦板的设置能够有效提高主缆的抗滑能力,但水平摩擦板应用相对局限。
[Abstract]:Multi-tower and multi-span suspension bridge is an important structural form of bridge spanning wide water area. The imperfection of calculation theory and construction technology has become an important factor restricting its development. The existence of "mid-tower effect", that is, the opposite relationship between the anti-slip safety of main cable and the ratio of deflection to span, is one of the contradictions that must be solved in the design of multi-tower suspension bridge. At present, the calculation parameters of anti-skid of the main cable are limited to the general arrangement of the structure and the form of load, and the method of model test is used to extract the nominal friction coefficient in practical engineering. In view of the real slip of cable strands in saddle groove and the analysis of force transfer mechanism, it is necessary to establish a fine contact model between main cable and cable saddle. In this paper, the main cable saddle anti-sliding problem is discussed in the following three aspects: 1) based on Abaqus / explicit platform, the local fine modeling of the main cable saddle system is carried out, and the contact friction relationship between steel wire and steel wire, steel wire and saddle groove is accurately set up. The lateral force distribution model of a certain number of steel wires in a single slot is calculated and analyzed, and the arrangement of cable strands is discussed. The influence of cable tension and friction coefficient between members on lateral force distribution. (2) based on Abaqus / explicit platform, the whole structure of cable saddle system is modeled, and the lateral force conversion results under the same conditions are substituted to simulate the corresponding layer-slip state. The displacement form of cable strands, the stress variation at both ends of cable strands and the stress distribution model of steel wire along the length of cable are calculated and studied. In view of the problem of anti-slip of main cable saddle, the influence of cable strands arrangement, cable tension and friction coefficient between elements on the resistance to sliding is discussed. The effect of vertical friction plate or horizontal friction plate on improving the skid resistance is analyzed and evaluated. The main conclusions are as follows: the lateral force of cable strands is a negative exponential convergent curve distribution, and suddenly decreases at the bottom of the steel wire, the lateral force is the direct factor leading to stratification slip; The phenomenon of delamination slippage can be concluded as follows: the upper layer steel wire is prior to the lower layer steel wire slip, the middle steel wire is earlier than the outside steel wire slip before the same odd layer steel wire, when the bottom layer steel wire appears the limit slip, then the cable strand will slip as a whole; The setting of vertical friction plate and horizontal friction plate can effectively improve the skid resistance of the main cable, but the application of horizontal friction plate is relatively limited.
【学位授予单位】：西南交通大学
【学位级别】：硕士
【学位授予年份】：2017
【分类号】：U448.25

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