大直径薄壁圆筒结构土压力的研究.pdf

摘要大直径薄壁圆筒结构是一种新型的码头结构型式,该结构具有结构简单、材料用量省、受力条件好以及施工速度快、造价低、耐久性好的优点,越来越受到工程界的重视。土压力是其所受主要荷载之一,结构与土体之间作用机理十分复杂,有关计算理论还不够成熟,限制了该结构型式的广泛应用。本文在以往的研究成果和实践经验的基础上,深入研究了大圆筒结构内、外土压力的分布规律,提出了更加切合实际的作用在大圆筒结构上的土压力分布模式。其中着重研究了大圆筒结构墙后土压力在平面上的分布规律,以考虑相邻两个圆筒之间的微元土条的平衡为前提,结合大圆筒自身的形状特点,建立了一组平面上土压力分布的计算公式。在此基础之上,利用弹性力学有限单元法分别对大圆筒结构在不同的墙后土压力分布情况下的位移、内力进行了计算分析。研究成果表明本文提出的土压力计算公式比通常的经验公式在理论上更为严谨,应用上也更具有普遍性。关键词: 大圆筒结构土压力径向切向有限元 ABSTRACT Large diameter cylinder shell s仃1lctllreis anew structure applied in portengineering,because ofthesimple construction,economization of materials,good condition of the force suffered,rapid speed ofthe construction,little costandgood wear,it isattachedimportance moreand more inengineering earthpressure isthemain loadimposing on thes缸1lctuI℃.Because themechanism between structure and soiliS plex,and theoriesofsome calculation are not veryperfect,the broad application ofthis structure ofthe earth pressure distributionalong thedifferentsidesoflargediameter cylinder structure iSstudied,in thebaseoftheachievement oftheformerresearch and theexperience frompractice。the model isbe put 】∞ regulation of earthpressure’S distribution intheplane isstudied asan emphasis theequilibrium ofthesmall soilelements closetogether and theshape’S characteristics ofthecylinder,a formula that isapplied todescribe thedistribution ofthe earthpressure inthe plane isputforward,and acomparison witlltheexperiential formula isbe isapplied toanalyses thedisplacement and intemal force of the s仃ucture under thetwo different mode ofdislribution ofthe earth thestudy we can see thatthe new formula ofthe earth pressure is even more precise intheory and even more prevalent in application. Key words: Large cylinder s仃uctI】re:earthpressure;radial;tangential direct; FEM(Finite Element Method) 第一章绪论 ,船舶大型化趋势越来越明显,港口建设必将向外海深水区及大江、大河的入海口发展,国内外工程实践表明钢筋混凝土大直径圆筒结构具有旌工简捷、造价低、耐久性好等特点,且能适应水深、浪大、地基较软弱的恶劣环境,是