{
  "version": 1,
  "units": "m",
  "common": {
    "units": "m",
    "coordinates": "x=桥向，y=横向，z=向上",
    "width": 8,
    "crossSectionBudget": {
      "laneWidths": [
        3.5,
        3.5
      ],
      "edgeStrips": [
        0.5,
        0.5
      ]
    },
    "girderTop": 8,
    "overhang": 0.35,
    "bearingThickness": 0.18,
    "car": {
      "length": 4.6,
      "width": 1.8,
      "height": 1.5,
      "wheelbase": 2.7,
      "transverseCenter": 1.75,
      "sourceKind": "teaching_assumption"
    },
    "person": {
      "height": 1.75,
      "transverseCenter": -3.64,
      "yawDegrees": 90,
      "sourceKind": "teaching_assumption",
      "note": "侧身站于侧带，脚底在本桥桥面；不放大。"
    },
    "lineLoad": 100000,
    "lineLoadUnits": "N/m",
    "comparisonSpacing": 16,
    "display": {
      "geometryScale": 1,
      "carScale": 1,
      "memberThicknessScale": 1,
      "explosionOffset": 2.8
    },
    "spanDefinition": "教学支承中心间距；结构两端各外伸0.35 m。来源中的30 m跨度—梁高对被用于构造教学模型，不等同实桥预制梁长。"
  },
  "source": {
    "title": "规划省道三门至江山公路永康段工程（如春至白窖段）可行性研究报告（报批稿）",
    "publisher": "浙江省交通规划设计研究院",
    "date": "2021-01",
    "pages": "PDF 152–153，表5-6、5-7",
    "url": "https://zjjcmspublic.oss-cn-hangzhou-zwynet-d01-a.internet.cloud.zj.gov.cn/jcms_files/jcms1/web3586/site/attach/0/8cf398665d3e43bfafa4eb5e654fe77f.pdf",
    "note": "项目方案资料；只取30 m预制T梁高2.0 m、小箱梁高1.6 m这一尺寸对。其他尺寸为本课教学假定，不是该项目构造复原或现行标准断面。"
  },
  "types": [
    {
      "width": 8,
      "sourceKind": "teaching_assumption",
      "sourceNote": "16 m—0.80 m与QS-13空心板案例保持一致；本总览的桥宽、片数、孔形和壁厚仍为方案尺度示意，精确断面见图纸复原模型。",
      "sourceUrl": null,
      "id": "slab",
      "title": "装配式空心板",
      "shortTitle": "空心板",
      "spans": [
        16
      ],
      "length": 16,
      "depth": 0.8,
      "girderTop": 3,
      "deckThickness": 0.12,
      "material": "预应力混凝土",
      "system": "简支",
      "construction": "预制空心板 → 吊装 → 铰缝、桥面施工",
      "forceMode": "simple-analytical",
      "section": {
        "count": 8,
        "spacing": 1,
        "unitWidth": 0.98,
        "top": 0.16,
        "bottom": 0.15,
        "web": 0.14
      },
      "feature": "密排的薄矮空心板，板间铰缝与桥面共同承担横向联系。",
      "question": "把桥面移开后，纵向空腔和板间连接分别在哪里？",
      "mechanism": "荷载沿桥向传给两端支座；空腔减轻自重，板间连接使相邻板共同工作。",
      "parts": [
        "桥面层",
        "空心板顶板",
        "空心板底板",
        "空心板腹板",
        "板间连接",
        "端部封锚区",
        "支座",
        "桥台"
      ],
      "thumbnail": "thumbnails/slab.png",
      "spansLabel": "16 m",
      "depthLabel": "0.80 m",
      "maxSpan": 16,
      "supportStations": [
        0,
        16
      ]
    },
    {
      "width": 8,
      "sourceKind": "project_pair_with_teaching_details",
      "sourceNote": "项目方案资料；只取30 m预制T梁高2.0 m、小箱梁高1.6 m这一尺寸对。其他尺寸为本课教学假定，不是该项目构造复原或现行标准断面。",
      "sourceUrl": "https://zjjcmspublic.oss-cn-hangzhou-zwynet-d01-a.internet.cloud.zj.gov.cn/jcms_files/jcms1/web3586/site/attach/0/8cf398665d3e43bfafa4eb5e654fe77f.pdf",
      "id": "tee",
      "title": "预制PC T梁",
      "shortTitle": "PC T梁",
      "spans": [
        30
      ],
      "length": 30,
      "depth": 2,
      "girderTop": 6,
      "deckThickness": 0.18,
      "material": "预应力混凝土",
      "system": "简支",
      "construction": "预制、张拉 → 吊装T梁 → 横隔与湿接缝 → 桥面施工",
      "forceMode": "simple-analytical",
      "section": {
        "count": 4,
        "spacing": 2,
        "flangeWidth": 1.9,
        "top": 0.2,
        "web": 0.22,
        "bottomWidth": 0.55,
        "bottom": 0.25,
        "diaphragmStations": [
          0.6,
          7.5,
          15,
          22.5,
          29.4
        ]
      },
      "feature": "宽翼缘、薄腹板、下缘马蹄；横隔梁把分立T梁联成整体。",
      "question": "相同30 m跨度，T梁比小箱梁高0.4 m，空间构造又有哪些不同？",
      "mechanism": "翼缘与下缘形成抗弯力偶，腹板承担剪力；横隔和桥面参与横向分配。",
      "parts": [
        "桥面层",
        "T梁翼缘",
        "T梁腹板",
        "T梁马蹄",
        "湿接缝",
        "横隔梁",
        "支座",
        "桥台"
      ],
      "thumbnail": "thumbnails/tee.png",
      "spansLabel": "30 m",
      "depthLabel": "2.00 m",
      "maxSpan": 30,
      "supportStations": [
        0,
        30
      ]
    },
    {
      "width": 8,
      "sourceKind": "project_pair_with_teaching_details",
      "sourceNote": "项目方案资料；只取30 m预制T梁高2.0 m、小箱梁高1.6 m这一尺寸对。其他尺寸为本课教学假定，不是该项目构造复原或现行标准断面。",
      "sourceUrl": "https://zjjcmspublic.oss-cn-hangzhou-zwynet-d01-a.internet.cloud.zj.gov.cn/jcms_files/jcms1/web3586/site/attach/0/8cf398665d3e43bfafa4eb5e654fe77f.pdf",
      "id": "smallbox",
      "title": "预制PC小箱梁",
      "shortTitle": "PC小箱梁",
      "spans": [
        30
      ],
      "length": 30,
      "depth": 1.6,
      "girderTop": 5,
      "deckThickness": 0.18,
      "material": "预应力混凝土",
      "system": "简支",
      "construction": "预制、张拉 → 架设小箱梁 → 湿接缝、端横梁 → 桥面施工",
      "forceMode": "simple-analytical",
      "section": {
        "count": 4,
        "spacing": 2,
        "unitWidth": 1.9,
        "bottomWidth": 1.3,
        "top": 0.2,
        "bottom": 0.18,
        "web": 0.18,
        "diaphragmStations": [
          0.3,
          29.7
        ]
      },
      "feature": "每片主梁都是闭口薄壁箱；剖开可看见顶板、底板和两片斜腹板。",
      "question": "小箱梁的闭口截面与T梁的开口截面，对扭转和横向联系意味着什么？",
      "mechanism": "顶、底板主要参与纵向抗弯，腹板传剪；闭口截面形成环向剪流路径。",
      "parts": [
        "桥面层",
        "小箱梁顶板",
        "小箱梁底板",
        "小箱梁腹板",
        "湿接缝",
        "端横梁",
        "支座",
        "桥台"
      ],
      "thumbnail": "thumbnails/smallbox.png",
      "spansLabel": "30 m",
      "depthLabel": "1.60 m",
      "maxSpan": 30,
      "supportStations": [
        0,
        30
      ]
    },
    {
      "width": 8,
      "sourceKind": "teaching_assumption",
      "sourceNote": "本课给定的教学几何，用于比较构造与传力；不代表适用跨径范围。",
      "sourceUrl": null,
      "id": "box",
      "title": "连续变高度箱梁",
      "shortTitle": "连续箱梁",
      "spans": [
        60,
        60
      ],
      "length": 120,
      "depth": 2.4,
      "pierDepth": 4,
      "girderTop": 12,
      "deckThickness": 0.12,
      "material": "预应力混凝土",
      "system": "两跨连续；墩梁由支座连接",
      "construction": "支架分段现浇 → 张拉与体系形成 → 拆除支架",
      "forceMode": "continuous-qualitative",
      "section": {
        "count": 1,
        "topWidth": 8,
        "cellTopWidth": 5.6,
        "bottomWidth": 4.6,
        "top": 0.25,
        "bottom": 0.25,
        "web": 0.3,
        "haunchLength": 24
      },
      "feature": "一幅桥面对应一个大箱室，墩顶加高，梁在中墩支座上连续。",
      "question": "同样是墩顶加高，连续梁的支座与连续刚构的固结处有何区别？",
      "mechanism": "连续性在跨内与墩顶之间分配弯矩。墩顶一般出现负弯矩，上缘受拉；这里仅标示典型机制。",
      "parts": [
        "桥面层",
        "箱梁顶板",
        "箱梁底板",
        "箱梁腹板",
        "支点横隔",
        "支座",
        "桥墩",
        "桥台"
      ],
      "thumbnail": "thumbnails/box.png",
      "spansLabel": "60+60 m",
      "depthLabel": "2.4→4 m",
      "maxSpan": 60,
      "supportStations": [
        0,
        60,
        120
      ]
    },
    {
      "width": 8,
      "sourceKind": "teaching_assumption",
      "sourceNote": "本课给定的教学几何，用于比较构造与传力；不代表适用跨径范围。",
      "sourceUrl": null,
      "id": "composite",
      "title": "工字钢—混凝土组合梁",
      "shortTitle": "钢混组合梁",
      "spans": [
        40
      ],
      "length": 40,
      "depth": 2,
      "deckThickness": 0.25,
      "material": "钢主梁 + 钢筋混凝土桥面板",
      "system": "简支组合梁",
      "construction": "钢梁制造、架设 → 横向连接 → 桥面板施工 → 形成组合截面",
      "forceMode": "simple-analytical",
      "section": {
        "count": 4,
        "spacing": 2,
        "flangeWidth": 0.55,
        "top": 0.035,
        "bottom": 0.045,
        "web": 0.018,
        "studDiameter": 0.022,
        "studHeight": 0.15,
        "studPitch": 1,
        "diaphragmStations": [
          0.4,
          10,
          20,
          30,
          39.6
        ]
      },
      "feature": "钢工字梁托住混凝土桥面板，抗剪连接件使界面共同工作。",
      "question": "如果桥面板与钢梁之间可以自由滑动，还能按组合截面工作吗？",
      "mechanism": "正弯矩下混凝土桥面主要受压、钢梁下缘受拉；连接件传递界面纵向剪力。施工阶段与成桥截面不同。",
      "parts": [
        "混凝土桥面板",
        "钢梁上翼缘",
        "钢梁腹板",
        "钢梁下翼缘",
        "抗剪连接件",
        "横向联结系",
        "支座",
        "桥台"
      ],
      "thumbnail": "thumbnails/composite.png",
      "spansLabel": "40 m",
      "depthLabel": "2.00 m",
      "maxSpan": 40,
      "supportStations": [
        0,
        40
      ]
    },
    {
      "width": 8,
      "sourceKind": "teaching_assumption",
      "sourceNote": "本课给定的教学几何，用于比较构造与传力；不代表适用跨径范围。",
      "sourceUrl": null,
      "id": "rigid",
      "title": "连续刚构",
      "shortTitle": "连续刚构",
      "spans": [
        60,
        100,
        60
      ],
      "length": 220,
      "depth": 2.5,
      "pierDepth": 6,
      "girderTop": 24,
      "deckThickness": 0.12,
      "material": "预应力混凝土",
      "system": "墩梁固结；端部支座",
      "construction": "主墩、0号块 → 对称悬臂浇筑与张拉 → 边跨、中跨合龙",
      "forceMode": "frame-qualitative",
      "section": {
        "count": 1,
        "topWidth": 8,
        "cellTopWidth": 5.6,
        "bottomWidth": 4.6,
        "top": 0.25,
        "bottom": 0.25,
        "web": 0.4,
        "haunchLength": 40,
        "pierWallThickness": 0.55,
        "pierWallSpacing": 2.5
      },
      "feature": "双薄壁墩与箱梁固结，中墩没有支座；墩梁共同承担弯矩及变形协调。",
      "question": "合龙前的悬臂体系与合龙后的连续刚构，控制截面和传力路径如何改变？",
      "mechanism": "竖向荷载使梁弯曲，同时经固结节点向墩传递弯矩；温度、收缩与墩刚度也影响内力。需要框架或空间模型求解。",
      "parts": [
        "桥面层",
        "箱梁顶板",
        "箱梁底板",
        "箱梁腹板",
        "0号块横隔",
        "双薄壁桥墩",
        "墩梁固结节点",
        "端支座",
        "桥台"
      ],
      "thumbnail": "thumbnails/rigid.png",
      "spansLabel": "60+100+60 m",
      "depthLabel": "2.5→6 m",
      "maxSpan": 100,
      "supportStations": [
        0,
        60,
        160,
        220
      ]
    }
  ],
  "assumptions": [
    "除T梁/小箱梁30m—梁高对及空心板16m/0.80m对外，全部几何为教学假定；孔形、壁厚与布局不是图纸复原。",
    "端支座600mm桥向长，梁端外伸350mm；T/工字钢梁支座横宽480mm。",
    "大箱梁支座上设150mm梁底调平块，顶面适配变高度梁底。",
    "简支解析为整幅桥的等效线梁，不计算横向荷载份额。",
    "构造形成次序不等于施工阶段分析；刚构梁段展示0号块±4m与悬臂±46m。",
    "缩略图使用同一相机方向、各自取景，不可按图片尺寸同比；同尺度比较必须进入mode=compare。",
    "阶段与剖切不改变标准成桥参数；显示状态不作为计算模型。"
  ],
  "thumbnailProjection": {
    "camera": "orthographic",
    "direction": [
      0.8,
      0.67,
      1
    ],
    "fit": "individual, not equal-scale"
  },
  "evidence": "来源为项目方案而非实桥竣工图；不采用AI生成工程照片或图纸。"
}