{
  "units": "m",
  "coordinate_system": "x longitudinal, y transverse, z up; renderer V(x,y,z)=(x,z,-y)",
  "purpose": "Whole-bridge location context for source-informed educational component models",
  "contexts": {
    "suspension": {
      "source_module": "context/model.js",
      "source_model_id": "suspension_ground",
      "evidence_type": "existing_teaching_assumption",
      "deck_length": 144,
      "main_span_between_towers": 90,
      "deck_width": 7,
      "deck_z": 7,
      "hotspots": {
        "saddle": {
          "part_id": "saddle--1--1",
          "physical_position": [
            -45,
            -3.05,
            18.65
          ]
        },
        "clamp": {
          "part_id": "main-hanger--1--15",
          "physical_position": [
            -15,
            -3.05,
            10.65
          ]
        },
        "cablecrane": {
          "part_id": "main-cable--1",
          "physical_position": [
            0,
            -3.05,
            9.65
          ],
          "note": "标记主缆上的吊机作业位置；整桥仍作构造定位，不表示成桥留存设备"
        }
      }
    },
    "girder": {
      "source_module": "context-scene.js",
      "evidence_type": "teaching_assumption",
      "deck_length": 24,
      "support_centers_x": [
        -11.6,
        11.6
      ],
      "support_center_span": 23.2,
      "deck_width": 7.2,
      "girder_depth": 1.6,
      "deck_z": 5,
      "girder_y": [
        -2.4,
        0,
        2.4
      ],
      "diaphragm_x": [
        -11.6,
        -6,
        0,
        6,
        11.6
      ],
      "hotspots": {
        "prestress": [
          -12.1,
          -2.4,
          3.86
        ],
        "diaphragm": [
          0,
          -1.2,
          4.175
        ],
        "spherical": [
          11.6,
          -2.4,
          3.33
        ],
        "elastomeric": [
          11.6,
          2.4,
          3.33
        ]
      },
      "bearing_comparison": "Two bearing types occupy comparison markers; the assembly is not a real support schedule."
    },
    "arch": {
      "source_model_id": "arch_basket",
      "source_module": "context/model.js",
      "evidence_type": "existing_teaching_assumption",
      "hotspots": {
        "archhanger": [
          -16,
          -2.95,
          5.25
        ]
      },
      "note": "整桥下吊点仅定位；局部另选叉耳销轴构造，不冒称整桥原有锚块细节"
    },
    "stayed": {
      "source_model_id": "stayed_standard",
      "source_module": "context/model.js",
      "evidence_type": "existing_teaching_assumption",
      "hotspots": {
        "stayanchor": [
          -37.5,
          -6.25,
          8.3
        ]
      },
      "note": "整桥梁端定位；局部采用平行钢绞线型式"
    },
    "cantilever": {
      "source_model_id": "teaching_balanced_cantilever",
      "source_module": "supplement-contexts.js",
      "evidence_type": "teaching_assumption",
      "deck_width": 8,
      "deck_z": 13,
      "completed_arm_ends_x": [
        -22.5,
        22.5
      ],
      "current_segment_length": 3,
      "hotspots": {
        "traveler": [
          23,
          -2.5,
          14.3
        ]
      },
      "note": "墩顶固结的双悬臂位置示意；挂篮构造近景独立放大；未计算阶段平衡"
    }
  },
  "detail_mapping": "Detail scenes are independently magnified educational reconstructions of the selected component type; their scale is not the whole-bridge display scale.",
  "claims": {
    "as_built_reconstruction": false,
    "photo_metric_measurement": false,
    "capacity_verification": false
  }
}