Nc
nc
Bearing capacity factor Nc
Scores if within ±3% of the reference value.
Calculates ultimate and allowable bearing capacity of shallow foundations using Terzaghi's (1943) classical equation: qu = c*Nc*sc + q*Nq + 0.5*gamma*B*sg*Ngamma, with shape factors for strip, square, and circular footings. Includes water table correction for overburden and effective unit weight, and bearing capacity factors Nc, Nq from analytical expressions with Ngamma interpolated from standard tables.
with-tool: The model is given an executable Python calculator script.
Standards
One template produces many comparable benchmark tasks while keeping the scoring contract fixed.
01
The reusable contract shown on this page.
02
An archetype and site context are sampled.
03
Inputs may be hidden at harder tiers.
04
The model responds with the declared outputs.
Inputs the model receives, and the outputs it is scored on.
8 inputs
Included directly in every task prompt.
Footing width
footing_width_m
Footing width B
Embedment depth
embedment_depth_m
Foundation embedment depth Df
Footing shape
footing_shape
Footing shape
Factor of safety
factor_of_safety
Factor of safety for allowable capacity
Sampled from the scenario and inferable from its description.
Cohesion
cohesion_kpa
Effective cohesion c'
Derived from the archetype scenario. Hidden at hard difficulty.
Friction angle deg
friction_angle_deg
Effective friction angle phi'
Derived from the archetype scenario. Hidden at hard difficulty.
Unit weight
unit_weight_kn_m3
Soil unit weight gamma
Derived from the archetype scenario. Hidden at hard difficulty.
Used only when the sampled task needs this part of the contract.
Water table depth
water_table_depth_m
Depth to water table from ground surface
Optional input.
5 outputs
nc
Bearing capacity factor Nc
Scores if within ±3% of the reference value.
nq
Bearing capacity factor Nq
Scores if within ±3% of the reference value.
ngamma
Bearing capacity factor Ngamma
Scores if within ±5% of the reference value.
ultimate_bearing_capacity_kpa
Ultimate bearing capacity qu (kPa)
Scores if within ±3% of the reference value.
allowable_bearing_capacity_kpa
Allowable bearing capacity qa (kPa)
Scores if within ±3% of the reference value.
Each template is sampled at three tiers. Harder tiers may hide inputs, forcing the model to infer them from the scenario description.
All inputs given
All parameters given, strip footing, no water table
Footing shape restricted to: strip
Water table restricted to: False
All inputs given
All parameters given, any footing shape, water table present
Footing shape restricted to: strip, square, circular
Water table restricted to: True
Some inputs hidden
Some soil parameters hidden, water table present
Hidden inputs
Prompt replacement text
The foundation soil is {{ archetype.description }} ({{ archetype.site_context }})
Footing shape restricted to: square, circular
Water table restricted to: True
The exact instruction and parameter contract used to generate this task, pinned to the published library source.
/workspace
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 geotechnical engineer specializing in foundation design.2 3## Problem4 5Calculate the ultimate and allowable bearing capacity of a shallow foundation using Terzaghi's 1943 bearing capacity equation.6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11| Footing shape | {{ footing_shape }} | - |12| Footing width (B) | {{ footing_width_m }} | m |13| Embedment depth (Df) | {{ embedment_depth_m }} | m |14{% if cohesion_kpa is defined %}15| Effective cohesion (c') | {{ cohesion_kpa }} | kPa |16{% endif %}17{% if friction_angle_deg is defined %}18| Effective friction angle (φ') | {{ friction_angle_deg }} | degrees |19{% endif %}20{% if unit_weight_kn_m3 is defined %}21| Soil unit weight (γ) | {{ unit_weight_kn_m3 }} | kN/m³ |22{% endif %}23{% if water_table_depth_m is defined %}24| Water table depth | {{ water_table_depth_m }} | m |25{% endif %}26| Factor of safety | {{ factor_of_safety }} | - |27{% if archetype_description is defined %}28 29### Site Conditions30 31{{ archetype_description }}32{% endif %}33 34{% if tool_available %}35## Available Tool36 37A bearing capacity calculation tool is available at `/workspace/bearing_capacity_calc.py`. Run it with:38 39```bash40python3 /workspace/bearing_capacity_calc.py --help41```42 43You may use this tool to verify your calculations or compute values directly.44{% endif %}45 46## Required47 48Calculate the following:49 501. Bearing capacity factor Nc512. Bearing capacity factor Nq523. Bearing capacity factor Nγ534. Ultimate bearing capacity qu (kPa)545. Allowable bearing capacity qa (kPa)55 56## Applicable Standards57 58- Terzaghi, K. (1943) — Theoretical Soil Mechanics, John Wiley & Sons59 60## Constraints61 62- No internet access is available. Work from engineering knowledge and the provided tool.63- Use Terzaghi's original bearing capacity equation:64 - **Strip footing:** qu = c'·Nc + q·Nq + 0.5·γ·B·Nγ65 - **Square footing:** qu = 1.3·c'·Nc + q·Nq + 0.4·γ·B·Nγ66 - **Circular footing:** qu = 1.3·c'·Nc + q·Nq + 0.3·γ·B·Nγ67- Overburden pressure q = γ·Df68- Apply water table corrections when the water table is within the influence zone (above Df + B):69 - Use γ_w = 9.81 kN/m³70 - Adjust overburden pressure and effective unit weight based on water table position71- Allowable bearing capacity qa = qu / FoS72- For φ' = 0 (undrained clay): Nc = 5.7, Nq = 1.0, Nγ = 0.073 74## Output Format75 76Show your step-by-step working in Markdown, including formulas and intermediate calculations. At the end of your solution, include a JSON block with your final answers in exactly this format:77 78```json79{80 "nc": <numeric_value>,81 "nq": <numeric_value>,82 "ngamma": <numeric_value>,83 "ultimate_bearing_capacity_kpa": <numeric_value>,84 "allowable_bearing_capacity_kpa": <numeric_value>85}86```87 88Write your complete solution to `/workspace/output.md`.89 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.
soft_nc_clay
Soft normally consolidated clay
medium_dense_sand
Medium dense sand
stiff_oc_clay
Stiff overconsolidated clay
dense_sand
Dense sand
brisbane-alluvial-soft-nc-clay-preview — hard difficulty, some inputs hidden.
Soft normally consolidated clay. brisbane-alluvial. Required outputs: nc, nq, ngamma, ultimate_bearing_capacity_kpa, allowable_bearing_capacity_kpa
Scenario context and visible inputs.
Executable tool: terzaghi-bearing-capacity_calc.py
Inputs withheld at this difficulty.
Unit weight kn m3
unit_weight_kn_m3
Cohesion
cohesion_kpa
Friction angle deg
friction_angle_deg
Stand-in text in the prompt
The foundation soil is {{ archetype.description }} ({{ archetype.site_context }})
The scored JSON answer schema.
{
"nc": <number>,
"nq": <number>,
"ngamma": <number>,
"ultimate_bearing_capacity_kpa": <number>,
"allowable_bearing_capacity_kpa": <number>
}