نوع مقاله : پژوهشی
نویسندگان
1 عضو هیات علمی، گروه عمران، واحد شهرکرد، دانشگاه آزاد اسلامی، شهرکرد، ایران
2 استادیار، دانشکده مهندسی عمران و محیطزیست، دانشگاه صنعتی شیراز
چکیده
کلیدواژهها
عنوان مقاله [English]
نویسندگان [English]
Multi-channel Analysis of Surface Waves (MASW) is a method that can be used to determine the shear wave velocity profile in depth. Shear wave velocity is an important parameter for geotechnical, earthquake and geophysical engineers. Configuration of data acquisition in the MASW method is variable based on the purpose of the work (depth of identification, data resolution and etc.). For instance, the resolution of dispersion image will be different according to the recorded data by different configurations of the MASW method. Hence, in this paper, the effects of data-acquisition parameters on the resolution of dispersion spectrum are evaluated in frequency-velocity domain. These parameters consist of the receiver spacing, length of the receiver array, offset and the element size. Different receiver spacings of 8, 4, 2 and 1 meter are evaluated in two layered soil models with the shallow thickness of 2 and 4 meters. The distance between the source and the first receiver (offset) and the length of the receiver array are selected based on the desired depth and the maximum wavelength. In this regard, different lengths of the receiver array with dimensions of 96, 48, 24 and 12 meters are considered. Also, the different size of elements (1, 0.5, 0.25 and 0.125 m) are selected based on the shortest wavelength. The results show that the receiver spacing should be proportional to half of the shortest wavelength and minimum thickness of the shallow layer. The resolution range of the dispersion spectrum increases approximately twice by increasing the length of the receiver arrays from 12 m to 24, 24 to 48 and 48 to 96 m. Also, the results of the element resizing are shown that considering 8 or more elements (10) in one wavelength is necessary to obtain the optimal accuracy in the simulations. Generally, with regard to the condition of the site and the expected goal, it could be possible to obtain the suitable results with desirable accuracy in field-data acquisition analysis and software simulations by utilizing the effect of the mentioned parameters in different ranges. Moreover, the presented result in this paper can be used as guidelines for field parameters related to data acquisition in the MASW method.
کلیدواژهها [English]
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