Eccentricity
eccentricity_m
Eccentricity of resultant from base centre e (m)
Scores if within ±3% of the reference value.
Checks bearing pressure adequacy beneath a retaining wall base by computing the eccentricity of the resultant vertical load and applying Meyerhof's effective width method (B' = B - 2e). Compares the maximum bearing pressure on the reduced contact area against the allowable bearing capacity, using Meyerhof bearing capacity factors with depth corrections per AS 4678.
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.
Base width
base_width_m
Base width of the retaining wall footing B
Total vertical load kn per m
total_vertical_load_kn_per_m
Total vertical load on wall base per metre run V
Net moment knm per m
net_moment_knm_per_m
Net moment about base toe per metre run M
Allowable bearing capacity
allowable_bearing_capacity_kpa
Allowable bearing capacity of the foundation soil q_all
Sampled from the scenario and inferable from its description.
Soil cohesion
soil_cohesion_kpa
Foundation soil effective cohesion c'
Derived from the archetype scenario. Hidden at hard difficulty.
Soil friction angle deg
soil_friction_angle_deg
Foundation soil effective friction angle phi'
Derived from the archetype scenario. Hidden at hard difficulty.
Soil unit weight
soil_unit_weight_kn_m3
Foundation 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.
Embedment depth
embedment_depth_m
Embedment depth of wall base below ground surface Df
Optional input.
5 outputs
eccentricity_m
Eccentricity of resultant from base centre e (m)
Scores if within ±3% of the reference value.
effective_width_m
Meyerhof effective base width B' (m)
Scores if within ±3% of the reference value.
max_bearing_pressure_kpa
Maximum bearing pressure q_max (kPa)
Scores if within ±3% of the reference value.
ultimate_bearing_capacity_kpa
Ultimate bearing capacity q_ult (kPa)
Scores if within ±5% of the reference value.
factor_of_safety
Factor of safety against bearing failure FoS
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, stiff soil, low eccentricity expected
All inputs given
All parameters given, any soil type including soft clay
Some inputs hidden
Soil parameters hidden, agent must infer from site description
Hidden inputs
Prompt replacement text
The foundation soil is {{ archetype.description }} ({{ archetype.site_context }})
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 retaining wall design.2 3## Problem4 5Check the bearing pressure under a retaining wall base, accounting for eccentricity of the resultant vertical load using Meyerhof's effective width method.6 7## Given8 9| Parameter | Value | Unit |10|-----------|-------|------|11| Base width (B) | {{ base_width_m }} | m |12| Total vertical load (V) | {{ total_vertical_load_kn_per_m }} | kN/m |13| Net moment about toe (M) | {{ net_moment_knm_per_m }} | kN.m/m |14{% if soil_cohesion_kpa is defined %}15| Foundation soil cohesion (c') | {{ soil_cohesion_kpa }} | kPa |16{% endif %}17{% if soil_friction_angle_deg is defined %}18| Foundation soil friction angle (phi') | {{ soil_friction_angle_deg }} | degrees |19{% endif %}20{% if soil_unit_weight_kn_m3 is defined %}21| Foundation soil unit weight (gamma) | {{ soil_unit_weight_kn_m3 }} | kN/m³ |22{% endif %}23{% if embedment_depth_m is defined %}24| Embedment depth (Df) | {{ embedment_depth_m }} | m |25{% endif %}26| Allowable bearing capacity (q_all) | {{ allowable_bearing_capacity_kpa }} | kPa |27{% if archetype_description is defined %}28 29### Site Conditions30 31{{ archetype_description }}32{% endif %}33 34## Method35 36Use the following procedure to check bearing pressure under the wall base:37 38### Step 1 — Eccentricity39 40Calculate the eccentricity of the resultant from the base centre:41 42**e = B/2 - M/V**43 44where M is the net moment about the toe and V is the total vertical load.45 46### Step 2 — Effective Base Width (Meyerhof)47 48**B' = B - 2e**49 50This reduces the base width to account for the eccentric loading.51 52### Step 3 — Maximum Bearing Pressure53 54**q_max = V / B'**55 56This is the maximum bearing pressure on the effective footing area (strip footing per metre run).57 58### Step 4 — Ultimate Bearing Capacity59 60Calculate the ultimate bearing capacity using Meyerhof's equation for a strip footing on the effective width:61 62**q_ult = c' x Nc x dc + q x Nq x dq + 0.5 x gamma x B' x Ngamma x dgamma**63 64where q = gamma x Df (overburden pressure).65 66#### Bearing Capacity Factors (Meyerhof)67 68- N_q = exp(pi x tan(phi)) x tan^2(45 + phi/2)69- N_c = (N_q - 1) x cot(phi) [N_c = 5.14 when phi = 0]70- N_gamma = (N_q - 1) x tan(1.4 x phi)71 72#### Depth Factors (K_p = tan^2(45 + phi/2))73 74- d_c = 1 + 0.2 x sqrt(K_p) x (Df/B')75- d_q = d_gamma = 1 + 0.1 x sqrt(K_p) x (Df/B') for phi > 10 degrees; otherwise d_q = d_gamma = 176 77### Step 5 — Factor of Safety78 79**FoS = q_all / q_max**80 81## Constraints82 83- No internet access is available. Work from engineering knowledge and the provided tool.84- Use Meyerhof's effective width method (B' = B - 2e) to handle eccentric loading.85- The wall base acts as a strip footing (shape factors = 1.0, inclination factors = 1.0).86- Use the Meyerhof bearing capacity factors and depth factors as specified above.87- For phi = 0 (undrained clay): Nc = 5.14, Nq = 1.0, Ngamma = 0.0.88- gamma_w = 9.81 kN/m³ (if needed).89 90{% if tool_available %}91## Available Tool92 93A calculation tool is available at `/workspace/{{ meta.name }}_calc.py`. Run it with:94 95```bash96python3 /workspace/{{ meta.name }}_calc.py --help97```98 99You may use this tool to verify your calculations or compute values directly.100{% endif %}101 102## Required103 104Calculate the following:105 1061. Eccentricity of the resultant e (m)1072. Effective base width B' (m)1083. Maximum bearing pressure q_max (kPa)1094. Ultimate bearing capacity q_ult (kPa)1105. Factor of safety against bearing failure FoS111 112## Output Format113 114Show 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:115 116```json117{118 "eccentricity_m": <numeric_value>,119 "effective_width_m": <numeric_value>,120 "max_bearing_pressure_kpa": <numeric_value>,121 "ultimate_bearing_capacity_kpa": <numeric_value>,122 "factor_of_safety": <numeric_value>123}124```125 126Write your complete solution to `/workspace/output.md`.127 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
firm_clay
Firm clay
brisbane-alluvial-soft-nc-clay-preview — hard difficulty, some inputs hidden.
Soft normally consolidated clay. brisbane-alluvial. Required outputs: eccentricity_m, effective_width_m, max_bearing_pressure_kpa, ultimate_bearing_capacity_kpa, factor_of_safety
Scenario context and visible inputs.
Executable tool: wall-bearing_calc.py
Inputs withheld at this difficulty.
Soil unit weight kn m3
soil_unit_weight_kn_m3
Soil friction angle deg
soil_friction_angle_deg
Soil cohesion
soil_cohesion_kpa
Stand-in text in the prompt
The foundation soil is {{ archetype.description }} ({{ archetype.site_context }})
The scored JSON answer schema.
{
"eccentricity_m": <number>,
"effective_width_m": <number>,
"max_bearing_pressure_kpa": <number>,
"ultimate_bearing_capacity_kpa": <number>,
"factor_of_safety": <number>
}