沉入式大圆筒码头结构稳定性有限元分析方法研究

发布时间：2018-02-06 05:21

本文关键词： 沉入式大圆筒码头有限元强度折减法有限元位移控制法简化计算方法　出处：《天津大学》2014年硕士论文　论文类型：学位论文

【摘要】：沉入式大圆筒码头是一种新型的港口、海岸工程建筑物结构，相比于传统型式的结构，它并不需要很强的持力层，特别适用于软土地基，而且造价低、工期短，更能满足现如今高速发展的港口与海岸工程建设事业的高要求，拥有广阔的应用前景。然而，因为该新型结构的工作机理较为复杂，当前仍缺乏可以被普遍认可和应用的理论体系和计算方法，尤其结构的稳定性分析成为其应用与推广的关键问题。针对上述问题，本文采用有限元数值分析模型开展了针对沉入式大圆筒码头稳定性分析方法的研究工作，主要完成的工作包括了以下几方面内容： 1）建立沉入式大圆筒结构稳定性分析的有限元强度折减法，为解决大圆筒码头承载复杂、不便分析的难题，将常用于边坡稳定问题研究的有限元强度折减法应用于沉入式大圆筒结构的稳定性分析中。依据强度折减法的基本原理，建立三维弹塑性有限元分析模型，经过相应的稳定性分析步骤，确定结构的稳定性安全系数，并通过某防波堤工程算例，将该方法的计算结果与现有比较成熟的有限元加载系数法进行对比，验证了该方法的正确性与可行性。 2）采用有限元强度折减法，研究了沉入式大圆筒码头的失稳破坏模式及土压力分布性状，据此提出了圆筒结构的土压力简化计算方法；分析了沉入式大圆筒码头的稳定性影响因素以及该结构的整体失稳破坏模式。 3）建立沉入式大圆筒码头稳定性分析的有限元位移控制法，为求解大圆筒码头的极限承载力并避免有限元极值求解的不稳定性，采用有限元位移控制法分析大圆筒码头的稳定性。通过引入荷载合力作用点的位移增量反求荷载增量，直至达到极限状态，确定结构的极限承载力。分析极限状况下的结构受力特性，建立以极限承载力为主要因素的结构稳定性安全系数计算方法。 4）在有限元强度折减法的分析基础上，，建立了沉入式大圆筒码头抗倾稳定性分析的简化计算方法，并对比强度折减法的计算结果，验证了该简化算法的正确性。
[Abstract]:The submerged large - cylinder wharf is a new type of port and coastal engineering structure . Compared with the traditional structure , it does not need a strong holding layer , which is especially suitable for soft soil foundation , and has low cost and short construction period . It can meet the high demands of the port and coastal engineering construction cause of high - speed development . However , because the working mechanism of the new structure is more complex , there is still lack of theoretical system and calculation method which can be universally accepted and applied . Especially , the stability analysis of the structure becomes the key problem of its application and popularization . In view of the above problems , this paper adopts the finite element numerical analysis model to carry out the research work for the stability analysis method of the submerged large - cylinder wharf . The main tasks include the following aspects : Based on the basic principle of strength reduction , a three - dimensional elastic - plastic finite element analysis model is established . According to the basic principle of strength reduction and subtraction , a three - dimensional elastic - plastic finite element analysis model is established , the stability safety factor of the structure is determined according to the corresponding stability analysis step , and the calculation result of the method is compared with the existing finite element loading coefficient method , and the correctness and feasibility of the method are verified . 2 ) Finite element strength reduction method is used to study the unstable failure mode and the soil pressure distribution characters of the submerged large - cylinder wharf , and the simplified calculation method of soil pressure of the cylindrical structure is proposed . The stability influence factors of the submerged large - cylinder wharf and the overall instability failure mode of the structure are analyzed . 3 ) The finite element displacement control method for the stability analysis of the submerged large - cylinder wharf is established . In order to solve the problem of the ultimate bearing capacity of the large - cylinder wharf and avoid the instability of the finite element extreme value solution , the stability of the large - cylinder wharf is analyzed by the finite element displacement control method . The ultimate bearing capacity of the structure is determined by introducing the displacement increment of the acting point of the load resultant force , and the ultimate bearing capacity of the structure is determined . The structural stability safety factor calculation method with the ultimate bearing capacity as the main factor is established . 4 ) Based on the analysis of finite element strength reduction , a simplified calculation method for the anti - tilt stability analysis of the submerged large - cylinder wharf is established , and the correctness of the simplified algorithm is verified by comparing the calculation results of the strength reduction and subtraction .

【学位授予单位】：天津大学
【学位级别】：硕士
【学位授予年份】：2014
【分类号】：U656.11

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