【作者】 田利；

【导师】 李宏男；

【作者基本信息】 大连理工大学 ， 防灾减灾工程及防护工程， 2011， 博士

【摘要】 输电塔-线体系是重要的生命线工程,在我国经济建设中起着重要的作用。随着输电塔的高度和输电线的档距增加,近几十年地震导致输电塔-线体系破坏的现象不断出现。输电塔-线体系属于大跨度连续结构,所承受的地震地面运动是不同的,由行波效应、部分相干效应和局部场地效应等因素所致。对于输电塔-线体系大跨度空间结构,多维多点地震激励是其震害的主要原因之一,研究其在多维多点地震作用下的响应规律具有重要的现实意义。目前,关于输电塔-线体系地震响应分析中考虑多维多点地震效应的研究甚少,对于建立适合多维多点分析的计算模型也未有研究。本文对多维多点地震动输入,输电塔-线体系多维多点振动台试验,输电塔-线体系多维和多维多点地震响应分析,“折线型”输电线路多维多点地震响应以及“地形变化”输电线路多点地震响应等五个方面进行了研究,完成了以下主要研究内容：(1)针对输电塔-线体系这种连续结构,生成了多维多点地震动。利用迭代修正算法得到与《电力设施抗震设计规范》中地面加速度反应谱强度相当的地面加速度功率谱密度,并运用非线性最小二乘法对地面加速度功率谱密度进行拟合,得到了Clough-Penzien的修正过滤白噪声模型的参数。运用谐波叠加法生成了“直线型”多点地震动,针对“折线型”输电线路选用二维相干函数生成了“折线型”多点地震动,还给出了“地形变化”下多点地震动的生成方法；进一步推导了多维地震动分量之间的相关性,并生成了多维多点地震动时程。另外,布置了线状的强震观测系统,以期为研究这种体系提供基础性资料,并检验理论模型的正确性。(2)设计并制作了输电塔-线体系振动台试验模型,并进行了多维多点振动台试验研究。对输电塔-线体系试验模型非等比例问题进行了研究,完善了相似理论,并通过数值计算的方法加以验证。以500kV输电线路实际工程为背景,利用相似理论对输电塔模型和输电线模型进行了设计,制作了输电塔-线体系振动台试验模型。作者利用模拟地震振动台台阵系统对输电塔-线体系进行了多维多点振动台试验,试验结果表明：行波效应、部分相干效应和局部场地效应对体系响应有很大的影响,通过试验结果与数值分析的对比,验证了计算模型的合理性和考虑地震动多维多点的必要性,为进一步分析奠定了基础。(3)以辽宁盖州500kV直线塔为工程背景,建立了输电塔-线耦联体系的空间有限元模型,分别采用梁单元、杆单元和悬链线单元对输电塔、绝缘子和输电线进行了精确的模拟。对于悬挂式绝缘子,通过比较“三塔两线附加弹簧”模型和“三塔四线”模型,给出了适合多维多点分析的计算模型。选用不同场地类型的多条地震波对塔-线体系多维地震响应规律进行了总结。研究结果表明,纵向激励下输电塔的响应在多维激励中起主导作用,拟合了纵向激励下轴力最大值与三维激励下轴力最大值,并给出了拟合系数,供工程设计参考；对于输电线纵向和侧向位移仅考虑纵向或侧向激励就能得到最大值,而对于竖向最大位移需要考虑三向地震共同作用。利用生成的多维多点地震动时程,对塔-线体系多维多点地震响应规律进行了总结,研究结果表明：行波波速取值越低,塔-线体系的响应越大；相干性越弱,塔-线体系的响应越大；场地条件的差异性越大,塔-线体系的响应越大；多维多点分量间相干性对塔-线体系的响应影响很小,可以忽略。(4)根据辽宁某地区220kV耐张塔为工程背景,分别建立了“直线型”和“折线型”输电线路有限元模型。对“直线型”和“折线型”输电塔-线体系在多维多点地震激励下的响应进行对比研究,分析了由于折线对塔-线体系抗震性能带来的影响。选用SMART-I台阵多维多点地震动记录,分析多个折线角度的塔-线体系响应,得到不同角度下考虑多维多点地震效应对结构响应的影响不同。由直线型和折线型体系的多维多点响应结果表明：两种模型受行波效应的影响都很大,并且都随着行波波速的降低,反应更大；折线型受部分相干效应和局部场地效应的影响小于直线型的。(5)建立了“地形变化”输电线路有限元模型,对其进行了多点地震响应分析。分别研究了输电塔位于峰顶和谷底两种情况,研究结果表明：无论输电塔位于峰顶还是谷底受行波波速的影响很大,但两种模型受行波波速的影响程度不同,因此地震动的行波效应不可忽略；随着场地条件差异变大,结构的地震响应增大,对于输电塔位于峰顶的响应放大程度要大于输电塔位于谷底,因此应该考虑局部场地效应的影响。更多还原

【Abstract】 Transmission tower-line system is an important lifeline project, which plays an important role in Chinese economical construction. In recent decades, the transmission tower-line systems are often destroyed by earthquakes with the increasing of tower height and line span. Transmission tower-line system is a large span continuous structure, and induces to the different excitations of different supports due to wave passage effect, incoherence effect and local site effect. As to transmission tower-line system, multi-component and multi-support seismic excitation is one of the main reasons of seismic damage, and it is significant to analyze the seismic performance under multi-component and multi-support excitations. Presently, there are less studies on seismic response analysis of transmission tower-line systme considering multi-component and multi-support seismic effects. Meanwhile the calculation model considering multi-component and multi-support analysis is not found. The five aspects of work done in this thesis are listed as follows:(1) Multi-component and multi-support ground motion time histories are generated in view of the continuous structure of transmission tower-line system. Based on the design response spectrum defined in the Chinese Code for Design of Seismic of Electrical Installations, the power spectral density of the acceleration at the ground level is evaluated by an iterative approach. Using the nonlinear fitting technique, the model parameters can be obtained to fit the power spectral density function of the Clough-Penzien filtered white noise model and generated power spectral density function. Linear type, fold line type and topographic variation type multi-support ground motion time histories are generated, respectively. Furthermore, the correlations between every two components of multi-component ground motions are derived. Finally, multi-component and multi-support ground motion time histories are generated. In order to verify the accuracy of the theory model, strong motion seismographs are arranged.(2) Transmission tower-line system shaking table model is designed and made, and multi-component and multi-support shaking table experiment is carried out. Non-proportional in shaking table modeling power transmission tower-line system is studied, and the similarity theory is perfected and verified according to numerical calculation method. Based on the practical engineering, the transmission towers model and the transmission lines model are desigened, and the experimental model is made. The multi-component and multi-support shaking table experiment of transmission tower-line system is conducted according to shaking table arry system, and the natural vibration frequency between experimental model and finite model are compared. The experimental results show that wave passage effect, incoherence effect and local site effect have significant influence on the response of the system. From the comparison between experimental results and numerical analysis, the rationality of calculation model is verified, which lays the foundation for the further analysis.(3) Based on the practical engineering in Gaizhou city of Liaoning province, transmission tower-line system finite element model is established. The tower, the isolator and the transmission line are simulated by the beam element, truss element and catenary cable element, respectively. According to comaparing the structural system of three towers and two-span lines additional spring model with the model of three towers and four-span lines model, a resonable computational model is performed. The response of transmission tower-line system is analyzed under multi-component excitations, and earthquake waves are slected according to different site condition type. The results show that the response of transmission tower under longitudinal excitation is the most significant in multi-component excitations. The maximum axial force under longitudinal excitation and the maximum axial force under multi-component excitations are fitted, and the fitting factors are given which can provide a reference for engineering design. The longitudinal and transverse maximum displacement responses of transmission lines can be obtained under longitudinal excitation or transverse excitation, but the vertical maximum displacement reponses need to consider multi-component earthquake effects. The responses of transmission tower-line system under multi-component and multi-support excitations are analyzed. The results show that the response of the system is large when the traveling wave velocity is small, the degree of correlation is low, the differences of site conditions are large. Moreover, the correlations between every two components of multi-component earthquake motions have insignificant effect on the response of the system.(4) Based on the practical engineering in Liaoning province, linear type and fold line type transmission line finite eleemnt models are established, respectively. The dynamic characteristics of linear type and fold line type transmission tower-line system under multi-component and multi-support seismic excitations are compared. The seismic performance of the system caused by the influence of fold line is discussed. Multi-component and multi-support earthquake records in SMART-I array are selected, and the seismic response of multiple fold line angles type transmission tower-line system are analyzed. The results show that the responses of system under multi-component and multi-support seismic excitations are different when the angles are different. The responses of linear type and fold line type transmission tower-line system under multi-component and multi-support seismic excitations show that the two models are influenced significantly by wave passage effect, and the responses are large when the traveling wave velocity is low, and the responses of fold line type by the coherence loss effect and the local site effect are smaller than the responses of linear type structural system.(5) Topographic variation type transmission line system finite element model is established, and the responses of the model under multi-support seismic excitations are analyzed. The transmission towers are assumed to locate in the crest of peak and vally floor respectively. The results show that the traveling wave velocity has a significant effect on the two models, but the degree of the effect is different. Wave passage effect of earthquake ground motion can not be neglected. The larger is the difference between the site conditions, the larger are the responses of the structure. The responses of transmission tower located in the crest of peak are larger than the response of transmission tower located in the vally fllor. The effect of the local site effect should be taken into consideration.更多还原