【摘要】 本文对以GIS为基础的液化小区划技术进行了初步研究,收集唐山市区范围内的65个钻孔资料,将获得的有关砂土液化因素的属性信息和空间信息通过先进的Arc GIS技术组织成一个既能展现属性特征又能反映图形分布特征的地理信息数据库。根据钻孔勘测资料采用规范判别液化指数法和多因子线性回归液化判别法,运用Arc GIS中的VBA编程计算各测点的液化指数和液化势,采用克里格插值法由已知钻孔数据推测出未知钻孔数据区域的液化情况,最终得出基于Arc GIS的地震液化小区划图,为专家进行决策和工程应用提供直观系统的依据。借助专家对唐山大地震发生后三天拍摄的航拍片的解译,将其标定的液化范围与本文运用Arc GIS得出的液化小区划图进行对比,不同判别方法的液化等级分布与实际相符,验证了区划技术的适用性。此外虽然不同方法的液化判别成功率不同,但液化程度的分布都大致相同,与航拍片相一致,说明研究某一区域的液化程度和对某一种液化判别方法进行验证,不仅取决于测点的判别成功率,还可以从区划技术出发进行研究和验证。不同的判别方法得出的液化等级面积百分比有所不同,这取决于各个方法中参数的选取和方法的计算精度。更多还原

【Abstract】 Preliminary research on microzonation of liquefaction has been done based on Arc GIS,whichis the most appropriate after the screening of GIS technology. To assess liquefaction degree in the region of Tangshan city,totally 65 boreholes has been collected and the establishment of drilling graphics database and attribute database are completed on Arc GIS. The liquefaction index and liquefaction potential value has been calculated by the VBA program in Arc GIS with methods of code evaluation and multi-factor regression evaluation,seven factors and four factors for different precisions respectively. According to these drilling data,liquefaction condition for each borehole was discriminated,and the liquefaction condition of the unknown area was speculated by Kriging interpolation method,then the liquefaction zoning map of south of Tangshan and its southern region is presented based on ArcGIS. The results of each method have been compared by aerial map,which was took after 3 days of Tangshan earthquake. The results indicated that the distribution for the grade of liquefaction was roughly corresponded to theaerial map,albeit by different means,all this explained the applicability of Arc GIS. Different success rate of discriminant has the similar distribution,which illustrate the fact that the validating of the liquefaction method is not only depends on the success rate of discriminant,but also the division technology.更多还原