【作者】 廖祖伟；

【导师】 吕和林；

【作者基本信息】 西南交通大学 ， 岩土工程， 2008， 博士

【摘要】 根据国际研究动态,随着新材料和新结构不断地涌现与应用,针对我国未来防护工程建设(特别是高原高寒地区)对适应环境条件的新材料与新结构的迫切需要,研究和开发了钢板-支撑钢筋-聚氨酯泡沫三种不同材料复合而成的复合材料结构,通过系统的抗静载、动载力学性能试验、野外化爆试验及数值模拟,研究了这种新型复合材料结构的力学性能,提出了简化力学分析模型,同时研究了用该种复合材料结构制成的箱型浅埋工事在化爆作用下的受力性能,进而讨论了具体设计和应用施工的方法步骤,为这种结构材料的具体应用提供了基础。根据新材料的研究应用,提出钢板-支撑钢筋-聚氨酯泡沫复合材料结构及其复合成型工艺。复合结构在构造上采用上、下钢面板之间设置抗剪支撑钢筋,然后再与聚氨酯泡沫复合成型,使其抗剪、抗变形的能力大大提高,通过试验并和以往的夹层结构相比表明这种结构具有比承载能力高、延性和吸能特性好、抗爆能力强等特点。用数值模拟手段揭示了:不同受力状态下钢板-支撑钢筋结构的受力特性;钢板与支撑钢筋的相对刚度(或相对用量)对结构受力性能的影响;与结构轴向平行的彼此相邻两排钢筋的节间交叉排列与不交叉排列对结构受力性能影响。研究表明,钢筋充当压杆的作用,骨架结构的压屈是由于钢筋的失稳造成的;钢面板对钢筋起约束作用,这种作用影响着各钢筋临界压屈荷载以及平均轴向应力的分布情况。钢筋的节间距离s减小,压屈荷载增大,结构的临界压屈荷载也增大。钢板与钢筋的用量或相对刚度必须满足一个合理的关系。根据压杆与薄平板的稳定理论,分别推导了两种模型条件下骨架结构受剪临界荷载的计算公式。通过聚氨酯泡沫外包金属约束的原理性试验,研究了夹芯泡沫与外包薄金属层的相互作用,试验表明夹芯复合结构由于充填的聚氨酯对支撑钢筋和钢板产生约束作用,防止钢筋与钢板过早地屈曲,其承载及变形能力都要比骨架结构大得多;聚氨酯不但在受载前期能防止钢筋与钢板过早地屈曲,在后期仍能限制其进一步变形,使得夹芯复合结构在受载后期仍有较高的残余承载力。野外抗爆试验表明,复合材料结构具有良好的抗变形能力,能够经受住多次重复爆炸破坏而不丧失使用功能。复合材料结构可出现三塑性铰破坏机构和四塑性铰机动破坏机构两种破坏形态,试验结果可作为进一步研究复合材料结构抗爆分析方法的试验依据;在此基础上的进一步分析还表明,在相同爆深下,复合材料结构比粘钢混凝土板、混凝土板所承受的应力强度小,充分说明复合材料结构有良好的抗爆性能。通过正交各向异性厚板理论,提出了分析复合材料结构抗爆特性的简化方法,建立了分析模型,推导了刚度常数,建立了内力的基本方程,为这种新型复合材料结构的应用提供理论基础。基于一维平面波理论,提出应用梁式模型来分析复合材料结构组合成的浅埋地下箱体工事的受力,将地下箱体结构的顶板视作两端简支在弹性地基上的埋设梁,略去底板结构变形对顶板内力的影响,将梁离散为若干有限厚梁元(位移分量为垂直位移w、截面转角β、水平位移u),考虑横向剪切变形的影响,进行几何非线性计算。这一模型既考虑了箱体的整体运动,又考虑了顶板的挠曲变形,能有效且简便地对浅埋复合材料结构箱体进行受力计算。对复合材料装配式野战工事的设计进行了研究。工事应用设计需要根据战术技术要求来定,浅埋装配式野战工事往往顶板是最先破坏的部位,提出以梁的形式来计算和核算顶板,对于侧墙则以偏心受压构件来计算。工事的连接主要考虑搭接和串接紧固螺杆连接两种形式结合来完成,构件之间通过连接相互协同工作,充分发挥构件整体的变形能力。提出了复合材料装配式野战工事的施工技术要求。开挖平底坑是工事构筑的关键,快速开挖平底坑有机械和爆破开挖两种方法,要依据实际情况而定。依据试验提供了爆破开挖平底坑的有关方案数据,简要介绍了工事的安装,为工事的具体应用提供了方法依据。更多还原

【Abstract】 According to the international research trends,along with the appearance and application of new materials and new types of structures,aiming at meet the needs of new materials and structures applying to future defending project(especially in cold region of tableland),a kind of composite material structure composed of armor plate, supporting rebar and polyurethane foam is studied and developed.By means of systematic load bearing experiments(including dead load and live load),field chemical blast test and numerical modeling,the mechanical properties of this new material structure is studied.Then,the simplified mechanics model regarding the new material structure is established.Furthermore,the mechanical properties of shallow buried basket type work made of the new material under the effect of chemical blast are also studied.Finally,the specific design and construction methods are discussed. All of these research results may provide a theoretic basis for practical application of the new material structure.The composite material structure composed of armor plate,supporting rebar and polyurethane foam and its molding techniques are brought forward.This composite structure is made of two layers of armor plate(one on the top,the other on the bottom), supporting rebar which connect the two layers of armor plate and polyurethane foam filled in the interspace of the structure.According to the test results,compared with the interlayer structure used in the past,this new structure has higher loading capacity, better ductility,better capacity of absorbing energy,and stronger antidetonating ability.Three problems are studied by numerical modeling analysis,including the mechanical property of the structure which is composed of armor plate and supporting rebar under various load cases,the influence of the relative stiffness of armor plate and supporting rebar to the mechanical behavior of the structure and the influence of the arrangement pattern(crossed or uncrossed)of the two rows adjacent rebar to the mechanical behavior of the structure.The results show that the supporting rebar acts as compression bar and it is constrained by the armor plate.The constrained effect affects the ultimate compression load magnitude and the average axial stress distribution of the supporting rebar.The less the space between two rows adjacent rebar is,the more the ultimate compression load will be.The relative stiffness of the armor plate and the supporting rebar should be compatible.Based on the compression bar and thin plate stability theory,formulas used to calculate the critical shear resistant load of the framework corresponding to two conditions are deduced.The interaction between inner foam and outer thin metal shell is studied by test. The test results show that the interlayer composite structure can prevent rebar and armor plate from inflecting untimely and enhance its carrying capacity and stiffness because the inner polyurethane foam can help to restrict the supporting rebar and the armor plate from deforming.The polyurethane foam can not only stop the rebar and armor plate from inflecting untimely,but also restrict the deformation of the rebar and the armor plate latterly so as to ensure the structure still retain a relatively higher residual carrying capacity.The field blast test results show that the composite material structure has good deformation resistant capacity and can endure repetitious blast.The composite structure may have two types of failure mode which are three plastic hinge and four plastic hinge failure framework.The test results may become test references for further research in composite material structure.And the further study also shows that the undergoing stress intensity of the composite material structure is smaller than that of the reinforced concrete plate or concrete plate that means the composite structure has better anti detonation ability.On the basis of perpendicular anisotropy thick slab theory,a kind of simplified method used to analyze the anti detonation property of the composite material structure is developed.The analysis model,the stiffness constant and the basic equation for internal force are all developed.The simplified method can provide a theoretical basis for the application of this new composite material structure.Based on one dimensional plane wave theory,a method that beam model is applied to analyzing the stress status of shallow buried box shaped work made of composite material structure.In this model,the top slab of the underground box shaped structure is treated as a buried beam which is simple supported on the elastic foundation;the beam is divided into some finite thick beam elements(displacement components include vertical displacement w,rotation angel of sectionβand horizontal displacement u);transverse shear deformation of beam is considered.Then, geometrical nonlinearity calculation is performed for this model.In this model,both the mass motion of the framework and the distortion of the top slab are all considered. Consequently,this model may be used to analyze the stress status of the shallow buried box shaped structure made of composite material effectively.How to design package type field operations works with compound material is studied in this paper.Application design of work depends on technical requirement of strategy.Top slab is always destroyed at first in low-buried package type field operations.This paper brings forward using a beam model to calculate and check top slab,and eccentric compression bar to analyze side wall.That coveting over and joining-up in series binding bolt are mainly considered to deal with the connection of work,and in this way,the entire resistance to deformation of the work can be fully used.Construction technical requirements for package type field operations made of composite material are brought forward.Digging flat bottom pit is very important for constructing field operations.There are two methods to dig flat bottom pit,which are by machine and by blasting,and the choice of the method depends on practical situation.According to the test which provides the relative method and datum of digging flat bottom pit by blasting,the installation of the work is introduced which may contribute to the actual application of the work.更多还原