Bridge abutments: The bridge end columns are supported on the abutment beams. The abutment beams are divided into three sections. When erecting a single-row bridge, the truss end columns are supported on the middle section of the abutment beams. When erecting a double-row bridge, two bridge abutments are used, with the end columns supported on the middle sections of the abutment beams of the two bridge abutments respectively. When erecting a three-row bridge, two bridge abutments are still used. The inner row end columns are supported on the middle section of the abutment beam of one bridge abutment, and the middle and outer row end columns are supported on the two side sections of the abutment beam of the other bridge abutment respectively.