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前言近年来,随着高层建筑和其它大型建筑工程的兴建,在抗震设计方面,测定地基动力特性是十分必要的;随着工业的发展,大型动力设备的增多,也提出了测定地基动力特性的要求,以及弄清建筑物或设备和地基的复合振动等问题。在这方面,测定地基土层中弹性波的速度,从而推求地基土的动弹性常数,就是其中的一项重要途径。用波速法测定地基土的动力性质,只是测定地基土参数的一个方面,在土为匀质弹性体的假定下,介质中的弹性波速度和弹性模量、剪切模量及泊桑比有一定关系,对圆形基础和基底一定应力分布的情况,弹性波速度又和刚度系数有一定关系。国外,通过在软土地基上进行波速法测定的记录,发现剪切波速度与标准贯入N值及密度ρ呈现密切的联系。
Foreword In recent years, with the construction of high-rise buildings and other large-scale construction projects, it is necessary to measure ground dynamic characteristics in seismic design. With the development of industry and the increase of large-scale power equipment, the determination of ground dynamic characteristics has also been proposed. Requirements, as well as issues such as composite vibration of buildings or equipment and foundations. In this respect, the determination of the elastic wave velocity in the foundation soil and the calculation of the dynamic elastic constants of the foundation soil are an important approach. The determination of dynamic properties of foundation soil by wave velocity method is only one aspect of the determination of soil parameters. Under the assumption that the soil is a homogeneous elastomer, the elastic wave velocity and elastic modulus, shear modulus, and Poisson’s ratio in the medium are Certain relations, for the circular base and the base of a certain stress distribution, the elastic wave velocity and stiffness coefficient have a certain relationship. In foreign countries, through the recording of wave velocity method on soft soil foundation, it is found that the shear wave velocity is closely related to the standard penetration N value and density ρ.