岩土工程振动台试验理论及在地下管线动力响应研究中的应用

发布时间：2018-04-14 15:43

本文选题：岩土工程振动台试验 + 分离相似设计　；参考：《西南交通大学》2016年博士论文

【摘要】：我国很多大中城市处在地震高发区,而城市恰好是岩土工程结构和生命线设施聚集的地区,这就使得震区工程结构的抗震设计问题显得尤为重要。振动台模型试验是对工程结构地震响应进行研究的重要手段,经过近几十年的发展,振动台试验的研究成果已经越来越多的被应用在科学研究和工程实践当中,同时,振动台试验也面临着试验对象的大型化、试验对象的复杂化和试验设备飞速发展而配套技术相对落后等亟待解决的问题。解决上述问题的根本在于对当前振动台试验理论进行突破。鉴于目前的现状,本论文开展了岩土工程振动台试验理论的研究,基于常用的振动台试验相似律,依托分离量纲分析法,建立了新的适合于复杂工程原型-模型之间相似关系的模型试验分离相似设计方法。以分离相似设计结果为基础,开展了振动台模型土、模型结构及模型基岩相似材料的研究,提出适合于振动台试验的模型土和模型基岩相似材料设计方法。以某重要场地的地下管线为原型,并以考虑多点激励作用下地下管线地震响应的振动台试验为依托,地下管线的震害现象和规范计算方法为参照,对所发展的试验理论进行验证。通过开展上述工作,得到了以下结论：1)首次提出了分离量纲分析方法,基于分离量纲分析方法建立了复杂岩土工程振动台模型试验的分离相似设计体系,并利用分离相似设计方法对多点激励作用下地下管线地震响应振动台试验进行相似设计,得到分别属于模型土、模型管线和地震波各自的特征方程和关键设计参数的相似比。通过对特征方程进行分离,使模型试验中每个参数的设计权重得到了很好的表现,同时解决了传统相似设计方法要求所有参数必须满足相似比,而现实中模型设计又无法同时满足所有参数相似比之间的矛盾。2)确定了土的非线性、滞后性和应变累积性相似的核心在于动剪切模量比随剪应变变化关系的相似性。经过一系列参数对比研究后,推荐采用Stokoe模型中参考应变作为动剪切模量比变化曲线相似的控制指标。利用该方法进行了振动台试验模型土的设计,确定了粘土与河砂的质量比为1：1.5,含水率为14%的土为最终试验用土。建立了土动应力-动应变相似判定体系,通过检验原型土与模型土参考应变相似比、相关系数值、不均匀系数相似比、曲率系数相似比四个指标,保证了原型土和模型土动应力动应变关系的相似,重现了原型地下管线周围地基土在地震作用下的动力特性。3)提出了考虑波传播特性相似的模型基岩设计方法。根据模型试验的相似原理,研制出以粘土、重晶石粉、石膏等为原料的岩体相似材料。通过正交试验设计及物理力学性质试验,确定了相似材料中各原材料对基岩相似材料密度、参考应变和最大剪切模量的影响规律,基于这些影响规律,开展了模型基岩相似材料配制的动三轴试验,最终确定了模型试验软岩相似材料的最终质量比为粘土：重晶石粉：石膏=7.9：2.1：3。所配制的模型材料考虑了地震作用下剪切波速的相似比要求,适合用于振动台试验软岩相似材料的模拟。4)生成了具有空间相关性的多维多点人工地震动,以此为基础开展了多维多点地震动作用下地下管线地震响应的振动台试验,给出了地下管线的动力响应特性规律,并首次在振动台试验中得到了地下管线的扭转特性规律,同时,试验结论也为当前的管线抗震设计规范提出了一些建议。通过将本次振动台试验中地下管线的应变响应数据与规范计算结果进行比较,对本文开展的振动台试验的合理性给予了证明,进而对第二章至第四章提出的分离量纲分析法、模型土设计方法和模型基岩设计方法的合理性给予证明。本文所研究的岩土工程振动台试验理论可以很好的推进振动台试验技术的发展,缓解试验技术发展明显滞后于试验设备发展的现状。通过振动台试验得到的地下管线地震响应结果,对输油气管线、市政输水管线等生命线工程的抗震设计有很好的指导意义。整个论文的工作对减少大震震害的经济损失、保障能源和生活生产安全、提升我国岩土工程抗震水平具有重要的意义。
[Abstract]:Many large and medium-sized city in China in the earthquake region, and the city is just the geotechnical engineering structure and lifeline facilities gathering areas, which makes the seismic design of earthquake engineering structure is particularly important. The shaking table model test is an important means for structural seismic response are studied, after decades of development, research the shaking table test has been widely used in scientific research and engineering practice, at the same time, shaking table test is also facing a large-scale test object, the test object is complex and test equipment and supporting the rapid development of technology is relatively backward to solve such problems. The fundamental to solve the problem is to break the current vibration test theory. In view of the current situation, this paper carried out the research of vibration test theory in geotechnical engineering, used in the shaking table test based on similarity Based on the separation of law, dimensional analysis, the establishment of a new suitable for complex engineering prototype model similarity model test of the relationship between the separation of similar design method. In order to separate the similar design results as the foundation, carried out the shaking table model of soil, material of similar model structure and model of soil and bedrock, the proposed model is suitable for vibration model of bedrock the test of similar materials. The design method of underground pipeline of an important site for the prototype, and to consider the earthquake shaking table test of underground pipeline under multipoint excitation response based on the underground pipeline damage phenomenon and calculation method for reference, to verify the test theory development. By carrying out the above work, get the following conclusions: 1) first proposed the separation method of dimension analysis, separation dimension analysis method is established for shaking table model test of complex geotechnical engineering based on similarity. Accounting system, and the separation of similar design method of shaking table test on the seismic response of underground pipeline under multipoint excitation of similar design, obtained belong to soil model, model of pipeline and seismic wave equations and their respective characteristics of the key design parameters of similar ratio. By separating the characteristic equation, the weight of each parameter in the model test design have a very good performance, at the same time to solve the traditional similar design method requires all parameters must satisfy the similarity ratio, but in reality it cannot satisfy all model design parameters similar to.2 ratio between contradictions) determine the soil nonlinearity, hysteresis and strain accumulation of core similarity lies in the dynamic shear modulus ratio with shear strain the relationship of similarity. After a series of parametric studies, as recommended by the dynamic shear modulus ratio curve is similar to the reference strain in Stokoe model The control index is designed. The shaking table test model of soil using the method to determine the quality of clay and sand ratio was 1:1.5, the soil water content was 14% for the final test soil. The soil dynamic stress-strain similarity judgment system, through prototype test of soil and soil reference strain than similar models, the correlation coefficient, uneven coefficient of similarity ratio, curvature coefficient similarity ratio of four indicators, the prototype model of soil and soil dynamic stress-strain relationship similar to reproduce the.3 dynamic properties of foundation soil around buried pipeline prototype under earthquake) put forward wave propagation model design method considering similar bedrock according to the principle of similar model test, developed by clay, barite, gypsum rock and other raw materials for similar materials. Through the experiment of orthogonal design and the physical and mechanical properties, the raw material base of similar materials Rock similar material density, influence of reference strain and maximum shear modulus, the influence law based on the developed model of bedrock similar three triaxial test materials preparation, and ultimately determine the quality of the final model test of soft rock similar material than clay: Barite powder: Gypsum =7.9:2.1:3. model material prepared by considering the earthquake action under the shear wave velocity similarity requirement, suitable for.4 simulation of shaking table test of soft rock similar material) to generate multidimensional spatial correlation with multi point artificial ground motion, as a basis to carry out the multi support seismic action for vibration test under the seismic response characteristics of underground pipeline, dynamic response of underground pipelines is given and, for the first time in the shaking table test are rules and torsional characteristics of underground pipelines at the same time, test results for pipeline current seismic design code is put forward Some suggestions. Through the vibration response of underground pipeline test response data and the standard calculation results of shaking table test was carried out in this paper proved the rationality of the separation, then put forward to the second dimension to the fourth chapter of the analysis model of soil, design methods and design methods of the rationality for bedrock model proof. The development of geotechnical engineering vibration test theory in this paper can well promote the shaking table test technology, test technology to alleviate the current situation lagged behind the development of test equipment development. Through shaking table test results of seismic response of underground pipelines, oil pipelines, a good guide for seismic design of municipal water line lifeline engineering. The whole thesis work to reduce earthquake losses, protect the energy and life safety, enhance China's geotechnical engineering The earthquake resistance level is of great significance.

【学位授予单位】：西南交通大学
【学位级别】：博士
【学位授予年份】：2016
【分类号】：TU990.3;TU435

【参考文献】