diff --git a/B05_Profile/B05_Profile_UI_Corridor_Structures.ts b/B05_Profile/B05_Profile_UI_Corridor_Structures.ts
index 83c18eafd..00de70541 100644
--- a/B05_Profile/B05_Profile_UI_Corridor_Structures.ts
+++ b/B05_Profile/B05_Profile_UI_Corridor_Structures.ts
@@ -48,6 +48,7 @@ import {
 import { computeRevetmentLayout } from "../B06_Section/B06_Section_UI_Cross_Revetment";
 import { withoutGuardedFill } from "../B06_Section/B06_Section_UI_Cross_Body_Guard";
 import { chuteBands, fordPavementChute } from "./B05_Profile_UI_Corridor_Structures_Chute";
+import { isChuteSegment } from "../B06_Section/B06_Section_UI_Cross_Wall_Hatch";
 
 /** 스윕 프레임 하나 — 노선 위 한 지점의 중심 XY·좌향 단위벡터와 종단 표고 오프셋. */
 export interface StructureFrame {
@@ -588,8 +589,8 @@ export function buildCorridorStructures(
           wall.role,
         );
     }
-    // 도수로 · 돌붙임 띠 — 유출 성토 조각(단 사이 포함) · 유출 벽 길이(135-3).
-    chuteBands(layout.outletFill.segments, section.culvert?.chute).forEach((band) =>
+    // 도수로 · 돌붙임 띠 — 유출 성토 조각(단 사이 포함) · 묻힌 끝 3도 절토 조각(152-3) · 유출 벽 길이(135-3).
+    chuteBands(layout.outletFill.segments, section.culvert?.chute, isChuteSegment).forEach((band) =>
       pushSwept("chute", band, outletSpan.beforeM, outletSpan.afterM, null, "chute"),
     );
     // 다단은 **단별 구간값**을 따른다(2026-08-29 사용자 — 단마다 연장이 다르다).
diff --git a/B05_Profile/B05_Profile_UI_Corridor_Structures_Chute.ts b/B05_Profile/B05_Profile_UI_Corridor_Structures_Chute.ts
index fdf929128..20cbd37d8 100644
--- a/B05_Profile/B05_Profile_UI_Corridor_Structures_Chute.ts
+++ b/B05_Profile/B05_Profile_UI_Corridor_Structures_Chute.ts
@@ -19,14 +19,16 @@ interface FillSegment {
   points: OffsetPoint[];
 }
 
-/** 유출 성토 조각들 → 띠 단면 폴리곤들. 상자를 안 골랐거나 두께가 없으면 빈 목록. */
+/** 유출 성토 조각들 → 띠 단면 폴리곤들. 상자를 안 골랐거나 두께가 없으면 빈 목록.
+ *  `keep` = 띠가 서는 조각 — 기본 성토만(박스 · 세월교 본체 끝) · 관 · 흙막이는 `isChuteSegment`(152-3). */
 export function chuteBands(
   segments: ReadonlyArray<FillSegment>,
   chute: ChuteSpec | null | undefined,
+  keep: (segment: FillSegment) => boolean = (segment) => segment.kind !== "cut",
 ): OffsetPoint[][] {
   if (!chute) return [];
   return segments.flatMap((segment) => {
-    if (segment.kind === "cut") return [];
+    if (!keep(segment)) return [];
     const band = chuteBandOutline(segment.points, chute.thickness_m);
     return band ? [band.outline] : [];
   });
diff --git a/B06_Section/B06_Section_UI_Cross_Box.ts b/B06_Section/B06_Section_UI_Cross_Box.ts
index fd5820f08..d9e4ff93a 100644
--- a/B06_Section/B06_Section_UI_Cross_Box.ts
+++ b/B06_Section/B06_Section_UI_Cross_Box.ts
@@ -162,7 +162,7 @@ export function appendBoxOverlay(
       layer,
       layout.sides
         .filter((side) => side.wingRole === "outlet")
-        .flatMap((side) => side.fillSegments.filter((s) => s.kind !== "cut").map((s) => s.points)),
+        .flatMap((side) => side.fillSegments.filter((s) => s.kind !== "cut")),
       box.chute,
       x,
       toDisplayY,
diff --git a/B06_Section/B06_Section_UI_Cross_Culvert.ts b/B06_Section/B06_Section_UI_Cross_Culvert.ts
index 45a79ad0c..a8fedd0e0 100644
--- a/B06_Section/B06_Section_UI_Cross_Culvert.ts
+++ b/B06_Section/B06_Section_UI_Cross_Culvert.ts
@@ -22,7 +22,11 @@ import type {
   WallLayout,
 } from "./B06_Section_UI_Cross_Culvert_Geom";
 import { appendWallTrench, foundationChoice } from "./B06_Section_UI_Cross_Excavation";
-import { appendChuteBand, appendWallHatch } from "./B06_Section_UI_Cross_Wall_Hatch";
+import {
+  appendChuteBand,
+  appendWallHatch,
+  isChuteSegment,
+} from "./B06_Section_UI_Cross_Wall_Hatch";
 
 // 기하 계산 진입점과 공개 상수·타입은 여기서 재수출한다 — B05(최소 토피)와 횡단 뷰가
 // 이 모듈 경로로 이미 참조하고 있어 분리 후에도 import 경로를 바꾸지 않는다.
@@ -110,11 +114,12 @@ export function appendCulvertOverlay(
       : `${name} 절토선 — 3도 선이 원지반을 못 만나 절토 경사로 원지반까지`;
   };
   const drawOutletFill = (): void => {
-    // 도수로 · 돌붙임 띠(90-2) — 유출 끝 ~ 원지반 성토 조각(단 사이 포함) · 연동 카드엔 안 그림
+    // 도수로 · 돌붙임 띠(90-2) — 유출 끝 ~ 원지반 성토 조각(단 사이 포함) · 묻힌 끝 3도 절토 조각(152-3)
+    // · 연동 카드엔 안 그림
     if (culvert.chute && !linked)
       appendChuteBand(
         layer,
-        layout.outletFill.segments.filter((s) => s.kind !== "cut").map((s) => s.points),
+        layout.outletFill.segments.filter(isChuteSegment),
         culvert.chute,
         x,
         toDisplayY,
diff --git a/B06_Section/B06_Section_UI_Cross_Ford.ts b/B06_Section/B06_Section_UI_Cross_Ford.ts
index fc9f3324c..f5577ca81 100644
--- a/B06_Section/B06_Section_UI_Cross_Ford.ts
+++ b/B06_Section/B06_Section_UI_Cross_Ford.ts
@@ -136,7 +136,7 @@ export function appendFordOverlay(
       layer,
       layout.sides
         .filter((side) => side.role === "outlet")
-        .flatMap((side) => side.fillSegments.filter((s) => s.kind !== "cut").map((s) => s.points)),
+        .flatMap((side) => side.fillSegments.filter((s) => s.kind !== "cut")),
       ford.chute,
       x,
       toDisplayY,
diff --git a/B06_Section/B06_Section_UI_Cross_Ford_Pavement.ts b/B06_Section/B06_Section_UI_Cross_Ford_Pavement.ts
index 6dc7ab614..f833f5624 100644
--- a/B06_Section/B06_Section_UI_Cross_Ford_Pavement.ts
+++ b/B06_Section/B06_Section_UI_Cross_Ford_Pavement.ts
@@ -182,7 +182,7 @@ export function appendFordPavementOverlay(
       "b06-chart__ford-deck",
     ),
   );
-  if (spec.chute) appendChuteBand(svg, [outletFillLine(design)], spec.chute, x, y);
+  if (spec.chute) appendChuteBand(svg, [{ points: outletFillLine(design) }], spec.chute, x, y);
   return true;
 }
 
diff --git a/B06_Section/B06_Section_UI_Cross_Wall_Hatch.ts b/B06_Section/B06_Section_UI_Cross_Wall_Hatch.ts
index 2be9fbf51..2a982696c 100644
--- a/B06_Section/B06_Section_UI_Cross_Wall_Hatch.ts
+++ b/B06_Section/B06_Section_UI_Cross_Wall_Hatch.ts
@@ -349,14 +349,23 @@ export function chuteBandOutline(
   return { top, normals, outline: [...top, ...bottom.reverse()] };
 }
 
+/** 띠가 서는 유출 조각(152-3) — 성토 조각 + 내림 · 수평 절토 조각(3도 절토선 · 끝 ≤ 시작).
+ *  3도 선이 못 만나 복합경사로 오르는 절토 조각은 뺌. B06 관 · 흙막이 띠와 3D 띠가 같은 거름. */
+export function isChuteSegment(segment: { kind?: string; points: OffsetPoint[] }): boolean {
+  if (segment.kind !== "cut") return true;
+  const { points } = segment;
+  return points.length > 1 && points[points.length - 1].elevation <= points[0].elevation + 1e-6;
+}
+
 /**
  * 도수로 · 돌붙임 띠(90-2) — 유출 성토사면 선(윗면 = 사면선)을 사면 안쪽(아래)으로 두께만큼 오프셋한
  * 띠 · 안에 돌(흙막이 돌과 같은 그리기 · 두께 인자). 선마다 한 띠 · 그림만(면적 · 터파기 무관).
  * 도수로 · 돌붙임 형상 같음 · 배관 · 박스 · 세월교 오버레이가 부름(B07 은 오버레이를 따라옴).
+ * 절토 조각(`kind: "cut"` · 152-3)은 3도 절토선 따라.
  */
 export function appendChuteBand(
   layer: SVGElement,
-  lines: OffsetPoint[][],
+  lines: ReadonlyArray<{ points: OffsetPoint[]; kind?: string }>,
   chute: { structure: string; thickness_m: number },
   x: (offset: number) => number,
   toDisplayY: (elevation: number) => number,
@@ -365,15 +374,16 @@ export function appendChuteBand(
   if (!(thickness > 0)) return;
   const pixelsPerMeter = Math.abs(x(1) - x(0)) || 1;
   const px = (p: OffsetPoint): [number, number] => [x(p.offset), toDisplayY(p.elevation)];
-  for (const raw of lines) {
-    const shape = chuteBandOutline(raw, thickness);
+  for (const line of lines) {
+    const shape = chuteBandOutline(line.points, thickness);
     if (!shape) continue;
     const { top, normals, outline } = shape;
     const band = document.createElementNS(SVG_NS, "polygon");
     band.setAttribute("points", outline.map((p) => px(p).join(",")).join(" "));
     band.setAttribute("class", "b06-chart__culvert-pitching");
     const title = document.createElementNS(SVG_NS, "title");
-    title.textContent = `유출부 ${chute.structure} — 두께 ${thickness.toFixed(2)}m · 성토사면 따라 원지반까지`;
+    const along = line.kind === "cut" ? "3도 절토선" : "성토사면";
+    title.textContent = `유출부 ${chute.structure} — 두께 ${thickness.toFixed(2)}m · ${along} 따라 원지반까지`;
     band.append(title);
     clipSeq += 1;
     const clipId = `b06-chute-clip-${clipSeq}`;
diff --git a/resources/tester/helper_135_3_chute_solid.cjs b/resources/tester/helper_135_3_chute_solid.cjs
index d55aba449..befdea96a 100644
--- a/resources/tester/helper_135_3_chute_solid.cjs
+++ b/resources/tester/helper_135_3_chute_solid.cjs
@@ -49,7 +49,7 @@ const B06 = (f) => path.join(ROOT, "B06_Section", `${f}.ts`);
 const { buildCorridorStructures } = loadTs(B05("B05_Profile_UI_Corridor_Structures"));
 const { structureHashParts } = loadTs(B05("B05_Profile_UI_Corridor_Structures_Hash"));
 const { structureTopLoops } = loadTs(B05("B05_Profile_UI_Corridor_Tin_Design"));
-const { chuteBandOutline } = loadTs(B06("B06_Section_UI_Cross_Wall_Hatch"));
+const { chuteBandOutline, isChuteSegment } = loadTs(B06("B06_Section_UI_Cross_Wall_Hatch"));
 const { computeBoxLayout } = loadTs(B06("B06_Section_UI_Cross_Box_Geom"));
 const { computeFordLayout } = loadTs(B06("B06_Section_UI_Cross_Ford"));
 const { outletFillLine } = loadTs(B06("B06_Section_UI_Cross_Ford_Pavement"));
@@ -181,7 +181,7 @@ function check(name, section, expectedBands, expectedLength, strip) {
   const { culvertLayoutOf } = loadTs(B05("B05_Profile_UI_Corridor_Structures"));
   const layout = culvertLayoutOf(s);
   const bands = (layout?.outletFill.segments ?? [])
-    .filter((g) => g.kind !== "cut")
+    .filter(isChuteSegment) // 묻힌 끝 3도 절토 조각도(152-3)
     .map((g) => chuteBandOutline(g.points, 0.3)?.outline)
     .filter(Boolean);
   const spec = s.culvert.outlet;
diff --git a/resources/tester/helper_152_3_chute_cut.cjs b/resources/tester/helper_152_3_chute_cut.cjs
new file mode 100644
index 000000000..9bbaf3331
--- /dev/null
+++ b/resources/tester/helper_152_3_chute_cut.cjs
@@ -0,0 +1,112 @@
+/* 152-3 도수로 띠 절토 조각 헬퍼 — 묻힌 유출 끝 3도 절토선에도 띠 · 오르막 복합경사 절토엔 띠 없음.
+ * 화면 TS(`_Cross_Wall_Hatch` 거름 · 단면 · B05 3D `chuteBands`)를 그 자리에서 돌림 · 짝 = `test_152_3_chute_cut.py`.
+ * 입력 = 139-4 와 같은 픽스처(박스 352.14 · 배관 85.052 원지반 고친 사본).
+ */
+const fs = require("fs");
+const path = require("path");
+const ts = require(path.join(__dirname, "..", "..", "config", "node_modules", "typescript"));
+
+const ROOT = path.join(__dirname, "..", "..");
+const cache = new Map();
+const STUBS = { "@ui/ui_template_toast": { showToast: () => undefined } };
+
+function loadTs(file) {
+  const full = path.resolve(file);
+  if (cache.has(full)) return cache.get(full);
+  const js = ts.transpileModule(fs.readFileSync(full, "utf8"), {
+    compilerOptions: {
+      module: ts.ModuleKind.CommonJS,
+      target: ts.ScriptTarget.ES2020,
+      esModuleInterop: true,
+    },
+  }).outputText;
+  const box = { exports: {} };
+  cache.set(full, box.exports);
+  const localRequire = (request) => {
+    if (STUBS[request]) return STUBS[request];
+    const alias = { "@util/": "common_util", "@ui/": "ui_template", "@config/": "config" };
+    for (const [prefix, dir] of Object.entries(alias))
+      if (request.startsWith(prefix))
+        return loadTs(resolve(path.join(ROOT, dir, request.slice(prefix.length))));
+    return loadTs(resolve(path.join(path.dirname(full), request)));
+  };
+  new Function("exports", "module", "require", js)(box.exports, box, localRequire);
+  cache.set(full, box.exports);
+  return box.exports;
+}
+const resolve = (base) =>
+  [base, `${base}.ts`, path.join(base, "index.ts")].find(
+    (p) => fs.existsSync(p) && fs.statSync(p).isFile(),
+  ) ?? `${base}.ts`;
+
+const B06 = (f) => path.join(ROOT, "B06_Section", `${f}.ts`);
+const { computeStoredLayouts } = loadTs(B06("B06_Section_Structure_Layouts"));
+const { isChuteSegment, chuteBandOutline } = loadTs(B06("B06_Section_UI_Cross_Wall_Hatch"));
+const { chuteBands } = loadTs(
+  path.join(ROOT, "B05_Profile", "B05_Profile_UI_Corridor_Structures_Chute.ts"),
+);
+const fixture = (name) =>
+  JSON.parse(fs.readFileSync(path.join(__dirname, "fixtures", name), "utf8")).cross_sections;
+const clone = (v) => JSON.parse(JSON.stringify(v));
+const r3 = (v) => Math.round(v * 1000) / 1000;
+const CHUTE = { structure: "돌붙임", thickness_m: 0.3 };
+
+/** 유출 조각마다 — 종류 · 오르막 · 띠 섬 · 띠 윗면이 그 선 · 아랫면이 선 아래(두께). */
+function study(section, list) {
+  const culvert = computeStoredLayouts(section, list).culvert;
+  const segments = culvert.outletFill.segments;
+  const kept = segments.filter(isChuteSegment);
+  return {
+    segments: segments.map((g) => {
+      const [a, b] = [g.points[0], g.points[g.points.length - 1]];
+      const band = isChuteSegment(g) ? chuteBandOutline(g.points, CHUTE.thickness_m) : null;
+      const top = band?.top ?? [];
+      const bottom = band ? band.outline.slice(top.length) : [];
+      return {
+        kind: g.kind ?? "fill",
+        rises: b.elevation > a.elevation + 1e-6,
+        band: !!band,
+        topIsLine: !!band && top.length === g.points.length,
+        below: band
+          ? r3(
+              Math.min(...top.map((p, i) => p.elevation - bottom[bottom.length - 1 - i].elevation)),
+            )
+          : null,
+      };
+    }),
+    // 3D 띠(관 · 흙막이 = isChuteSegment) · 기본 거름(박스 · 세월교 본체 끝 = 성토만)
+    bands3d: chuteBands(segments, CHUTE, isChuteSegment).length,
+    bands3dFillOnly: chuteBands(segments, CHUTE).length,
+    kept: kept.length,
+  };
+}
+
+const out = {};
+const bodies = fixture("b06_73_4_body_guard_sections.json");
+out.box = study(
+  bodies.find((s) => Math.abs(s.chainage_m - 352.14) < 0.6),
+  bodies,
+);
+
+const pipes = fixture("b07_cross_overlay_sections.json");
+const pipe = pipes.find((s) => s.culvert && !s.culvert.hidden_pipe);
+const base = computeStoredLayouts(pipe, pipes).culvert;
+const tail = base.outletFill.segments[base.outletFill.segments.length - 1];
+const start = tail.points[0];
+const outward = Math.sign(tail.points[1].offset - start.offset) || 1;
+function reshaped(rise, slope) {
+  const s = clone(pipe);
+  for (const p of s.samples) {
+    const t = ((p.offset_m ?? 0) - start.offset) * outward;
+    if (t >= 0 && typeof p.elevation_m === "number")
+      p.elevation_m = start.elevation + rise + slope * t;
+  }
+  return study(
+    s,
+    pipes.map((x) => (x === pipe ? s : x)),
+  );
+}
+out.pipeBase = study(pipe, pipes);
+out.pipeDown = reshaped(0.3, -0.15); // 3도 선이 원지반을 만남
+out.pipeUp = reshaped(0.3, 0.1); // 오르막 → 복합경사 절토
+process.stdout.write(JSON.stringify(out));
diff --git a/resources/tester/helper_90_chute_band.cjs b/resources/tester/helper_90_chute_band.cjs
index 13708c8f2..d61db73a6 100644
--- a/resources/tester/helper_90_chute_band.cjs
+++ b/resources/tester/helper_90_chute_band.cjs
@@ -49,7 +49,7 @@ const run = (line) => {
   const layer = new Node("g");
   appendChuteBand(
     layer,
-    [line],
+    [{ points: line }],
     { structure: "돌붙임", thickness_m: 0.3 },
     (o) => o * SCALE,
     (e) => -e * SCALE,
diff --git a/resources/tester/test_152_3_chute_cut.py b/resources/tester/test_152_3_chute_cut.py
new file mode 100644
index 000000000..01421f9d3
--- /dev/null
+++ b/resources/tester/test_152_3_chute_cut.py
@@ -0,0 +1,65 @@
+"""152-3 도수로 · 돌붙임 띠 — 묻힌 유출 끝 3도 절토선(내림 · 수평)에도 띠 · 오르막 복합경사 절토엔 없음.
+
+화면 TS 를 그 자리에서 돌린 값(`helper_152_3_chute_cut.cjs`) · B06 관 · 흙막이 띠와 3D 띠가 같은 거름.
+"""
+
+import json
+import subprocess
+from pathlib import Path
+
+import pytest
+
+ROOT = Path(__file__).resolve().parents[2]
+HELPER = Path(__file__).parent / "helper_152_3_chute_cut.cjs"
+NODE_MODULES = ROOT / "config" / "node_modules"
+
+pytestmark = pytest.mark.skipif(not NODE_MODULES.is_dir(), reason="프론트엔드 의존성 미설치")
+
+
+@pytest.fixture(scope="module")
+def out() -> dict:
+    done = subprocess.run(  # noqa: S603 — 고정 실행 파일
+        ["node", str(HELPER)], cwd=str(ROOT), capture_output=True, text=True, encoding="utf-8"
+    )
+    assert done.returncode == 0, done.stderr
+    return json.loads(done.stdout)
+
+
+def _src(relative: str) -> str:
+    return (ROOT / relative).read_text(encoding="utf-8")
+
+
+def test_묻힌_흙막이_유출_3도_선에_띠(out: dict) -> None:
+    (cut,) = out["box"]["segments"]
+    assert cut["kind"] == "cut" and not cut["rises"]
+    assert cut["band"] and cut["topIsLine"]  # 윗면 = 3도 선
+    assert cut["below"] == pytest.approx(0.3, abs=0.01)  # 선 아래 두께
+    assert out["box"]["bands3d"] == 1 and out["box"]["bands3dFillOnly"] == 0
+
+
+def test_배관_묻힌_끝_내림이면_띠_오르막이면_없음(out: dict) -> None:
+    down = out["pipeDown"]["segments"]
+    assert [s["kind"] for s in down] == ["fill", "cut"]
+    assert all(s["band"] for s in down)
+    up = out["pipeUp"]["segments"]
+    assert up[-1]["kind"] == "cut" and up[-1]["rises"] and not up[-1]["band"]
+    assert out["pipeDown"]["bands3d"] == 2 and out["pipeUp"]["bands3d"] == 1
+
+
+def test_성토만인_측점은_그대로(out: dict) -> None:
+    base = out["pipeBase"]
+    assert base["bands3d"] == base["bands3dFillOnly"] == 2
+
+
+def test_거름_한_벌_배선() -> None:
+    culvert = _src("B06_Section/B06_Section_UI_Cross_Culvert.ts")
+    assert "layout.outletFill.segments.filter(isChuteSegment)," in culvert
+    corridor = _src("B05_Profile/B05_Profile_UI_Corridor_Structures.ts")
+    assert (
+        "chuteBands(layout.outletFill.segments, section.culvert?.chute, isChuteSegment)" in corridor
+    )
+    hatch = _src("B06_Section/B06_Section_UI_Cross_Wall_Hatch.ts")
+    assert '"3도 절토선"' in hatch
+    # 박스 · 세월교 본체 끝은 성토만(3도 규칙 안 넓힘)
+    for name in ("B06_Section_UI_Cross_Box.ts", "B06_Section_UI_Cross_Ford.ts"):
+        assert 'side.fillSegments.filter((s) => s.kind !== "cut")' in _src(f"B06_Section/{name}")