{
  "schema": "bridge-dimension-contract/1",
  "units": "m",
  "evidence_type": "sourced_project_facts_with_teaching_assumptions",
  "coordinate_system": "x_longitudinal_y_transverse_z_up",
  "scope": "虎门大桥主航道单跨悬索桥；主跨按已核尺寸重建，塔、背索与锚碇为简化配景，不代表完整竣工模型",
  "bridge": {
    "type": "ground_anchored_single_span_suspension",
    "spans": [
      888
    ],
    "total_length": 888,
    "deck_width": 35.6,
    "girder_depth": 3.01,
    "cable_sag": 84.57142857142857,
    "tower_height_above_deck": 92.57142857142857,
    "cable_plane_y": [
      -17.2,
      17.2
    ],
    "tower_stations_x": [
      -444,
      444
    ],
    "tower_leg_y": [
      -19.3,
      19.3
    ],
    "tower_leg_width": 2.6,
    "hanger_spacing": 12,
    "hanger_diameter": 0.052,
    "main_cable_diameter": 0.7,
    "minimum_cable_above_deck": 8,
    "backstay_run": 200,
    "deck_datum_z": 0,
    "water_visual_z": -56,
    "section_yz": [
      [
        -17.8,
        -1.1
      ],
      [
        -15.6,
        0
      ],
      [
        15.6,
        0
      ],
      [
        17.8,
        -1.1
      ],
      [
        13.8,
        -3.01
      ],
      [
        -13.8,
        -3.01
      ]
    ]
  },
  "road": {
    "lane_widths": [
      3.75,
      3.75,
      3.75,
      3.75,
      3.75,
      3.75
    ],
    "other_widths": [
      2,
      3.35,
      3.35,
      2.2,
      2.2
    ],
    "definitions": [
      "中央分隔2m",
      "两侧边带各3.35m",
      "两侧风嘴水平投影各2.2m"
    ],
    "evidence_type": "teaching_assumption",
    "note": "6车道来自公开项目资料；车道带分配仅用于闭合35.6m总宽，不冒称实桥施工横断面。闭合：22.5+2+6.7+4.4=35.6m。"
  },
  "assets": [],
  "facts": [
    {
      "id": "L",
      "value_m": 888,
      "definition": "悬索桥主跨",
      "source_id": "P3",
      "evidence_type": "sourced_project_fact",
      "page_printed": 712,
      "page_pdf_1based": 2,
      "section": "1.1"
    },
    {
      "id": "B",
      "value_m": 35.6,
      "definition": "含两侧风嘴的主梁总宽",
      "source_id": "P3",
      "evidence_type": "sourced_project_fact",
      "page_printed": 712,
      "page_pdf_1based": 2,
      "section": "1.1"
    },
    {
      "id": "D",
      "value_m": 3.01,
      "definition": "作者原文§1.1记载的箱梁高3.01m",
      "source_id": "P3",
      "evidence_type": "sourced_project_fact",
      "page_printed": 712,
      "page_pdf_1based": 2,
      "section": "1.1"
    },
    {
      "id": "f",
      "value_m": 84.57142857142857,
      "definition": "由论文垂跨比1/10.5乘888m得到主缆垂度",
      "source_id": "P1",
      "evidence_type": "derived_geometry"
    },
    {
      "id": "section_outline",
      "definition": "扁平闭口流线箱梁和两侧风嘴身份参照图7；本页折点并非原图精确节点",
      "source_id": "P2",
      "figure": "图7，印刷696页，PDF第3页",
      "evidence_type": "visual_interpretation"
    },
    {
      "id": "hanger_spacing",
      "value_m": 12,
      "definition": "吊索纵向间距",
      "source_id": "P3",
      "page_printed": 712,
      "page_pdf_1based": 2,
      "section": "1.1",
      "evidence_type": "sourced_project_fact"
    }
  ],
  "assumptions": [
    "只重建888m主跨，主缆采用抛物线；不把200m背索水平投影称为虎门实际边跨。",
    "主缆横距、主缆直径、最低缆高、塔柱截面和横梁位置为显示假设；吊索间距12m采用作者原文。",
    "塔上部高度由最低缆高8m+来源垂度得到，不是来源中的实测塔高；水面标高仅布景。",
    "断面六个折点、车道宽及中央/边带分配、水马0.8m高×0.55m宽、护栏与抑流板尺寸均为教学示意。",
    "水马开关表示两侧边缘连续围挡的气动影响，不复原每个真实摆放位置；不添加不明尺度车辆。"
  ],
  "display": {
    "deformation_factor": 60,
    "section_displacement_factor": 4,
    "member_thickness_factor": 1,
    "hanger_display_diameter_m": 0.16,
    "hanger_thickening_factor": 3.076923076923077,
    "marker_radius_m": 0.75
  },
  "sources": {
    "P1": "https://www.sciencedirect.com/science/article/pii/S0167610521003391",
    "P2": "https://pubs.cstam.org.cn/article/doi/10.7638/kqdlxxb-2020.0105",
    "P3": "https://www.dengteam.com/uploadfile/2019/0127/20190127044127518.pdf"
  }
}