LIVEdataset aec-bench@releasetasks 552models 18disciplines 5last submission … · built …

civilwith-tool

Transition Spiral Length

Determines the governing minimum transition spiral length at rail curve entries by evaluating three independent criteria: cant runoff rate, cant deficiency rate of change, and twist limit. The maximum of L_cant, L_cd, and L_twist governs, ensuring passenger comfort and track stability per ARTC ETS-05-00 and AREMA Chapter 5.

with-tool: The model is given an executable Python calculator script.

Standards

AREMA MRE Chapter 5 ARTC ETS-05-00 EN 13803

How this task is generated

One template produces many comparable benchmark tasks while keeping the scoring contract fixed.

01
Template
The reusable contract shown on this page.
02
Scenario
An archetype and site context are sampled.
03
Difficulty tier
Inputs may be hidden at harder tiers.
04
Task prompt
The model responds with the declared outputs.

Parameters

Inputs the model receives, and the outputs it is scored on.

Inputs

6 inputs

Always given

Included directly in every task prompt.

Actual cant
actual_cant_mm
Applied (actual) cant E_a
0 – 150 mm
Cant deficiency
cant_deficiency_mm
Cant deficiency C_d at design speed
0 – 110 mm
Max speed
max_speed_km_h
Maximum operating speed V_max
20 – 250 km/h

Derived from scenario

Sampled from the scenario and inferable from its description.

Rate of change cant
rate_of_change_cant_mm_s
Maximum rate of change of cant D_cant
Derived from the archetype scenario. Hidden at hard difficulty.
25 – 55 mm/s
Rate of change cd
rate_of_change_cd_mm_s
Maximum rate of change of cant deficiency D_cd
Derived from the archetype scenario. Hidden at hard difficulty.
25 – 55 mm/s
Min twist ratio
min_twist_ratio
Minimum twist ratio (e.g. 400 means 1 mm cant per 400 mm length)
Derived from the archetype scenario. Hidden at hard difficulty.
400 – 800

Scored outputs

4 outputs

Spiral length cant

spiral_length_cant_m

Minimum spiral length from cant runoff criterion (m)

Scores if within ±3% of the reference value.

Spiral length cd

spiral_length_cd_m

Minimum spiral length from cant deficiency rate criterion (m)

Scores if within ±3% of the reference value.

Spiral length twist

spiral_length_twist_m

Minimum spiral length from twist rate criterion (m)

Scores if within ±3% of the reference value.

Governing spiral length

governing_spiral_length_m

Governing (maximum) minimum spiral length (m)

Scores if within ±3% of the reference value.

Difficulty

Each template is sampled at three tiers. Harder tiers may hide inputs, forcing the model to infer them from the scenario description.

easy

All inputs given

All parameters given, gentle curves on mainline or branch line

medium

All inputs given

All parameters given, any corridor type including tight metro curves and high speed

hard

Some inputs hidden

Rate-of-change limits and twist ratio hidden — agent must infer from corridor type and operating context

Hidden inputs

Rate of change cant mm srate_of_change_cant_mm_s
Rate of change cd mm srate_of_change_cd_mm_s
Min twist ratiomin_twist_ratio

Prompt replacement text

The track is a {{ archetype.description }} ({{ archetype.site_context }})

Task bundle

The exact instruction and parameter contract used to generate this task, pinned to the published library source.

/workspace

instruction.md
transition-spiral-length_calc.py

Teal lines show Jinja input conditions, not task visibility policy. A line renders only when that input or tool is visible.

1You are a senior civil engineer specializing in railway track geometry and alignment design.2 3## Problem4 5Determine the minimum transition spiral length to smoothly introduce curvature and superelevation on a curved track section. Three criteria must be checked and the governing (longest) length adopted.6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11| Maximum speed (V_max) | {{ max_speed_km_h }} | km/h |12| Actual cant (E_a) | {{ actual_cant_mm }} | mm |13| Cant deficiency (C_d) | {{ cant_deficiency_mm }} | mm |14{% if rate_of_change_cant_mm_s is defined %}15| Max rate of change of cant (D_cant) | {{ rate_of_change_cant_mm_s }} | mm/s |16{% endif %}17{% if rate_of_change_cd_mm_s is defined %}18| Max rate of change of cant deficiency (D_cd) | {{ rate_of_change_cd_mm_s }} | mm/s |19{% endif %}20{% if min_twist_ratio is defined %}21| Minimum twist ratio | 1:{{ min_twist_ratio }} | - |22{% endif %}23{% if archetype_description is defined %}24 25### Site Conditions26 27{{ archetype_description }}28{% endif %}29 30{% if tool_available %}31## Available Tool32 33A transition spiral calculation tool is available at `/workspace/{{ meta.name }}_calc.py`. Run it with:34 35```bash36python3 /workspace/{{ meta.name }}_calc.py --help37```38 39You may use this tool to verify your calculations or compute values directly.40{% endif %}41 42## Required43 44Calculate the following:45 461. Minimum spiral length from cant runoff criterion, L_cant (m)472. Minimum spiral length from rate of change of cant deficiency criterion, L_cd (m)483. Minimum spiral length from twist rate criterion, L_twist (m)494. Governing minimum spiral length (m)50 51## Applicable Standards52 53- ARTC Engineering Track Standard ETS-05-00 (Track Geometry)54- AREMA Manual for Railway Engineering, Chapter 5 (Track)55- EN 13803 (Railway Applications — Track Alignment Design Parameters)56 57## Constraints58 59- No internet access is available. Work from engineering knowledge and the provided tool.60- Use the following formulas:61  - Cant runoff: L_cant = (E_a × V_max) / (3.6 × D_cant)62    - where E_a is actual cant (mm), V_max is speed (km/h), D_cant is max rate of change of cant (mm/s)63  - Cant deficiency rate: L_cd = (C_d × V_max) / (3.6 × D_cd)64    - where C_d is cant deficiency (mm), D_cd is max rate of change of cant deficiency (mm/s)65  - Twist rate: L_twist = E_a × twist_ratio / 100066    - where twist_ratio is the minimum twist ratio (e.g. 400 means 1 mm cant per 400 mm of track length)67  - The governing spiral length is the maximum of the three values68{% if rate_of_change_cant_mm_s is not defined %}69- Typical rate of change of cant D_cant ranges from 35–55 mm/s depending on corridor type70{% endif %}71{% if rate_of_change_cd_mm_s is not defined %}72- Typical rate of change of cant deficiency D_cd ranges from 25–55 mm/s depending on corridor type73{% endif %}74{% if min_twist_ratio is not defined %}75- Typical minimum twist ratios range from 1:400 to 1:800 depending on corridor type and speed76{% endif %}77 78## Output Format79 80Show your step-by-step working in Markdown. At the end of your solution, include a JSON block with your final answers in exactly this format:81 82```json83{84  "spiral_length_cant_m": <numeric_value>,85  "spiral_length_cd_m": <numeric_value>,86  "spiral_length_twist_m": <numeric_value>,87  "governing_spiral_length_m": <numeric_value>88}89```90 91Write your complete solution to `/workspace/output.md`.92

Scenario archetypes

Each generated task is drawn from one of these realistic scenario bands.

Site contexts ground each scenario in a real locale the model can use to infer hidden values.

Urban metro

urban_metro

Urban metro or light rail line with tight curves and frequent stops

sydney-metro-northwestmelbourne-metro-tunnelbrisbane-cross-river-rail

Parameter ranges

actual_cant_mm: 40 – 100
cant_deficiency_mm: 30 – 75
max_speed_km_h: 40 – 80
rate_of_change_cant_mm_s: 35 – 55
rate_of_change_cd_mm_s: 35 – 55
min_twist_ratio: 400 – 500

Mainline freight

mainline_freight

Mainline freight corridor with gentle curves and heavy axle loads

artc-hunter-valley-coalartc-north-south-corridorpilbara-iron-ore-wa

Parameter ranges

actual_cant_mm: 30 – 80
cant_deficiency_mm: 20 – 60
max_speed_km_h: 60 – 115
rate_of_change_cant_mm_s: 35 – 45
rate_of_change_cd_mm_s: 25 – 40
min_twist_ratio: 500 – 800

High speed passenger

high_speed_passenger

High-speed passenger rail corridor with sweeping curves

sydney-melbourne-hsrbrisbane-gold-coast-fast-railperth-bunbury-fast-rail

Parameter ranges

actual_cant_mm: 80 – 150
cant_deficiency_mm: 50 – 110
max_speed_km_h: 130 – 250
rate_of_change_cant_mm_s: 25 – 40
rate_of_change_cd_mm_s: 25 – 40
min_twist_ratio: 600 – 800

Branch line

branch_line

Regional branch line with moderate curves and mixed traffic

nsw-north-coast-linevic-geelong-warrnamboolqld-western-line

Parameter ranges

actual_cant_mm: 20 – 80
cant_deficiency_mm: 15 – 60
max_speed_km_h: 20 – 80
rate_of_change_cant_mm_s: 35 – 55
rate_of_change_cd_mm_s: 35 – 55
min_twist_ratio: 400 – 600

Example task

sydney-metro-northwest-urban-metro-preview — hard difficulty, some inputs hidden.

Urban metro or light rail line with tight curves and frequent stops. sydney-metro-northwest. Required outputs: spiral_length_cant_m, spiral_length_cd_m, spiral_length_twist_m, governing_spiral_length_m

The model sees

Scenario context and visible inputs.

actual_cant_mm: 40 to 100 mm
cant_deficiency_mm: 30 to 75 mm
max_speed_km_h: 40 to 80 km/h

Executable tool: transition-spiral-length_calc.py

The model must infer

Inputs withheld at this difficulty.

Min twist ratio
min_twist_ratio
Rate of change cant mm s
rate_of_change_cant_mm_s
Rate of change cd mm s
rate_of_change_cd_mm_s

Stand-in text in the prompt

The track is a {{ archetype.description }} ({{ archetype.site_context }})

The model must produce

The scored JSON answer schema.

{
  "spiral_length_cant_m": <number>,
  "spiral_length_cd_m": <number>,
  "spiral_length_twist_m": <number>,
  "governing_spiral_length_m": <number>
}

spiral_length_cant_m · scored within ±3%
spiral_length_cd_m · scored within ±3%
spiral_length_twist_m · scored within ±3%
governing_spiral_length_m · scored within ±3%

Transition Spiral Length

How this task is generated

Template

Scenario

Difficulty tier

Task prompt

Parameters

Inputs

Scored outputs

Spiral length cant

Spiral length cd

Spiral length twist

Governing spiral length

Difficulty

easy

medium

hard

Task bundle

Scenario archetypes

Urban metro

Mainline freight

High speed passenger

Branch line

Example task

The model sees

The model must infer

The model must produce