【作者】 王军；

【导师】 王平安； 隋国秀；

【作者基本信息】 西安建筑科技大学 ， 建筑与土木工程， 2006， 硕士

【摘要】 对垫层地基、复合地基上的块体模型基础进行了现场激振法测试，在分析测试成果的基础上，讨论了各振型地基刚度系数之间的关系，发现天然地基各振型地基刚度系数之间关系的半经验公式并不适用于这两种类型的地基，提出了垫层地基和复合地基各振型刚度系数之间的关系。利用对垫层地基、复合地基场地的现场实测波速资料，根据弹性半空间计算模式实用化方法得到地基刚度系数计算值。通过对比分析地基刚度系数的实测值与计算值，发现在基础底面积较小的情况下，上述两种类型地基土的刚度系数计算值偏大。在从理论上分析了地基土刚度系数的各种影响因素后，提出了在考虑地基土的类型和波速范围的基础上，通过折减系数α修正地基刚度系数计算值的综合确定地基刚度系数的方法。对比分析了阻尼比实测值、计算值、经验值，提出在实际工程中通过经验方法确定阻尼比简单、易行、可靠，满足设计确定垫层地基和复合地基阻尼比的需要。论文得到的地基动力参数的实测值和综合确定方法，可供《动力机器基础设计》规范修订和工程设计参考。此外，分析了经验法、实测法和理论计算法确定的单桩竖向动刚度系数，讨论了桩基动力参数的影响因素，说明了经验法和理论计算法的优缺点。更多还原

【Abstract】 Through in-situ block-foundation forced vibration testing for cushion and complex subsoil, the test data are analyzed, the correlation between coefficients of subgrade different directions reaction are discussed, the correlation applying for natural subsoil is not suitable to cushion and complex subsoil, therefore, the available correlation for cushion and complex subsoil is brought forward.Utilizing test data of wave velocity measurement for cushion and complex subsoil, according to elastic half-space mode, coefficients of subgrade reaction are calculated. Coefficients of subgrade reaction obtained by calculation and test are contrastively analyzed, under the condition that foundation area is small, calculation value is on the high side. After influence factors of coefficients of subgrade reaction are taken into consideration in theroy, especially, variety of subsoil and range of wave velocity, the method of determining the coefficients of subgrade reaction through reduction coefficient α modifing calculation value is put forward.After damping ratios obtained by experimental, calculational, empiric method are contrastively analyzed, the data got by empiric method is proved that met the case in practice, moreover, this method is simple and convenient.The experimental data and method of determining dynamic parameter for cushion and complex subsoil supply reference to revising Code for design of dynamic machine foundation and designing in project.Additionally, dynamic parameters of single pile determined by empiric, experimental, academic three methods are analyzed, the influence factors are discussed, advantages and disadvantages of academic method are explained.更多还原