{
  "model": "tunnel_skeleton.glb",
  "scope": "4745~5480 (4+745~5+480)",
  "units": "m",
  "origin_plan_xy": [
    151090.911,
    483688.46
  ],
  "sources": {
    "centreline": "C0060302-001 CA-ALGN-STSM (side-tick midpoint)",
    "road_grade_B": "C0060302-002 CR-TABL-TEX2 (계획고=노면)",
    "GL_A": "C0060302-002 CR-TABL-TEX2 (지반고)",
    "section": "C0060303-001 CS-TABL-TEX1/2, CS-CONC-MAJR, CS-EXCV"
  },
  "approximations": [
    "walls vertical down to road; invert not modelled",
    "lining band thickness at walls is radial-consistent but not as-built",
    "centreline and grade linearly interpolated between nodes",
    "superelevation sign convention assumed (z += S/100 * x, x = left of tangent)"
  ],
  "layers": [
    "lining_outer_R7282",
    "lining_inner_R6982",
    "excavation_R7402",
    "road_surface_계획고",
    "ground_GL_지반고"
  ],
  "ring_step_m": 1.0,
  "ring_points": 43,
  "first_station": 4745,
  "pattern_status": "지보패턴: 엑셀 참고_지보패턴현황 당진방향 표(4+740~5+500, 42행, 빈틈 없음) 적용. 출처 data/pattern_stations_dangjin.csv (사용자 결정 2026-10-21)",
  "patterns": [
    {
      "from": 4740,
      "to": 4745,
      "pattern": "개착부"
    },
    {
      "from": 4745,
      "to": 4763,
      "pattern": "P-3"
    },
    {
      "from": 4763,
      "to": 4785,
      "pattern": "WL-2"
    },
    {
      "from": 4785,
      "to": 4796,
      "pattern": "WL-1"
    },
    {
      "from": 4796,
      "to": 4839,
      "pattern": "D-2"
    },
    {
      "from": 4839,
      "to": 4848,
      "pattern": "D-1"
    },
    {
      "from": 4848,
      "to": 4857,
      "pattern": "C-2"
    },
    {
      "from": 4857,
      "to": 4862,
      "pattern": "C-1"
    },
    {
      "from": 4862,
      "to": 4867,
      "pattern": "B-2"
    },
    {
      "from": 4867,
      "to": 4873,
      "pattern": "B-1"
    },
    {
      "from": 4873,
      "to": 4907,
      "pattern": "A"
    },
    {
      "from": 4907,
      "to": 4915,
      "pattern": "B-1"
    },
    {
      "from": 4915,
      "to": 4920,
      "pattern": "B-2"
    },
    {
      "from": 4920,
      "to": 4940,
      "pattern": "RP-1"
    },
    {
      "from": 4940,
      "to": 4988,
      "pattern": "C-1"
    },
    {
      "from": 4988,
      "to": 4998,
      "pattern": "B-2"
    },
    {
      "from": 4998,
      "to": 5006,
      "pattern": "B-1"
    },
    {
      "from": 5006,
      "to": 5019,
      "pattern": "B-2"
    },
    {
      "from": 5019,
      "to": 5025,
      "pattern": "B-1"
    },
    {
      "from": 5025,
      "to": 5110,
      "pattern": "A"
    },
    {
      "from": 5110,
      "to": 5130,
      "pattern": "RP-1"
    },
    {
      "from": 5130,
      "to": 5140,
      "pattern": "B-1"
    },
    {
      "from": 5140,
      "to": 5157,
      "pattern": "B-2"
    },
    {
      "from": 5157,
      "to": 5204,
      "pattern": "C-1"
    },
    {
      "from": 5204,
      "to": 5211,
      "pattern": "B-2"
    },
    {
      "from": 5211,
      "to": 5221,
      "pattern": "B-1"
    },
    {
      "from": 5221,
      "to": 5259,
      "pattern": "A"
    },
    {
      "from": 5259,
      "to": 5279,
      "pattern": "B-1"
    },
    {
      "from": 5279,
      "to": 5300,
      "pattern": "A"
    },
    {
      "from": 5300,
      "to": 5320,
      "pattern": "RP-1"
    },
    {
      "from": 5320,
      "to": 5357,
      "pattern": "A"
    },
    {
      "from": 5357,
      "to": 5363,
      "pattern": "B-1"
    },
    {
      "from": 5363,
      "to": 5377,
      "pattern": "B-2"
    },
    {
      "from": 5377,
      "to": 5390,
      "pattern": "C-1"
    },
    {
      "from": 5390,
      "to": 5399,
      "pattern": "C-2"
    },
    {
      "from": 5399,
      "to": 5406,
      "pattern": "D-1"
    },
    {
      "from": 5406,
      "to": 5427,
      "pattern": "D-2"
    },
    {
      "from": 5427,
      "to": 5446,
      "pattern": "D-1"
    },
    {
      "from": 5446,
      "to": 5462,
      "pattern": "WL-2"
    },
    {
      "from": 5462,
      "to": 5468,
      "pattern": "P-2"
    },
    {
      "from": 5468,
      "to": 5495,
      "pattern": "P-3"
    },
    {
      "from": 5495,
      "to": 5500,
      "pattern": "개착부"
    }
  ],
  "open": [
    "4+700~4+745 and 5+480~5+500 excluded ([미확정])",
    "지보패턴 측점표 적용(당진). 도면 E-1~2, RP-2, WL-3~4 는 당진 표에 없어 [미확정]. 대산 표 WL-4(4+758.85~4+768.85)는 참고만 [확인 필요]",
    "lining reference recorded (meta.lining_reference, 04-004~009); sheet-to-station mapping [미확정]",
    "[확정 2026-10-21] R1 6,982 mm 유지 (사용자 결정). 라이닝 도면 6장의 R1 6.892 m 표기는 확인 대상 오기로 기록",
    "pattern-group to excavation-pattern mapping: user explanation conflicts with filename (WL-4) - re-confirm [확인 필요]"
  ],
  "lining_reference": {
    "source": "C0060304-004..009 (콘크리트라이닝구조도)",
    "concrete": "fck 27 MPa",
    "rebar": "SD400 (fy 400 MPa)",
    "aggregate_mm": 25,
    "summary": "C0060304-004~009 | fck 27 MPa | SD400 | 입출구부 50 m 취약구간 철근 상세 (측점 대응 미확정)",
    "sheets": [
      {
        "sheet": "C0060304-004-콘",
        "groups": [
          [
            "A~C-2",
            "입출구부 50m"
          ]
        ]
      },
      {
        "sheet": "C0060304-005-콘",
        "groups": [
          [
            "E-1~2",
            "온도미고려"
          ],
          [
            "D-1~2",
            "입출구부 50m"
          ]
        ]
      },
      {
        "sheet": "C0060304-006-콘",
        "groups": [
          [
            "WL-1~2,RP-1~2",
            "온도미고려"
          ],
          [
            "E-1~2",
            "입출구부 50m"
          ]
        ]
      },
      {
        "sheet": "C0060304-007-콘",
        "groups": [
          [
            "WL-1~2",
            "입출구부 50m"
          ],
          [
            "WL-3~4",
            "온도미고려"
          ]
        ]
      },
      {
        "sheet": "C0060304-008-콘",
        "groups": [
          [
            "WL-3~4",
            "입출구부 50m"
          ]
        ]
      },
      {
        "sheet": "C0060304-009-콘",
        "groups": [
          [
            "P-2~3",
            "입출구부 50m"
          ]
        ]
      }
    ]
  }
}