安装前要对起重机安装跨度，金属结构主梁的拱度、水平旁弯，小车轨道高低差、轨距偏差，桥架对角线等进行测量。

To install the crane span before installation, camber, level of metal structure of main girder bending, trolley rail height difference, gauge deviation, diagonal bridge survey.

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对多数地区，等震线略具狭长的形状，经验点椭圆模型可以减小点源模型和断层破裂模型的系统偏差。

For most of the regions, isoseismals are of somewhat elongated shape. The empirical point-ellipse model can reduce systematic deviation of point-source and fault-rupture models.

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