Moving Load Case

A nested class within MovingLoad used to define and manage moving load cases for analysis, with support for country-specific standards like Indian and Eurocode.

Constructor

The main Case class constructor is for internal use. Please use the country-specific subclasses MovingLoad.Case.India or MovingLoad.Case.Eurocode to create load cases.

Country-Specific Subclasses

India

MovingLoad.Case.India(name, num_loaded_lanes, id=None, opt_auto_ll=False, opt_lc_for_permit=False, sub_load_items=None, scale_factor=None, permit_vehicle_id=None, ref_lane_id=None, eccentricity=None, permit_scale_factor=None)

Creates a moving load case according to Indian standards (IRC). It supports three main types of load cases: General, Auto Live Load Combination, and Permit Vehicle.

Parameters

name (str): The name for the load case.
num_loaded_lanes (int): The number of lanes to be loaded.
id (int, optional): A unique integer ID for the case. Auto-assigned if None.
opt_auto_ll (bool, optional): Set to True for "Auto Live Load Combinations". Defaults to False.
opt_lc_for_permit (bool, optional): Set to True for "Load Cases for Permit Vehicle". Defaults to False.
sub_load_items (list): A list of lists defining the sub-loads. The format depends on the selected options:
- Case 1: General Load (opt_auto_ll=False, opt_lc_for_permit=False) Each inner list must contain 5 items: [Scale Factor, Min Lanes, Max Lanes, Vehicle Name, [Selected Lanes]]
  - Scale Factor (float): Load combination factor.
  - Min Lanes (int): Minimum number of loaded lanes.
  - Max Lanes (int): Maximum number of loaded lanes.
  - Vehicle Name (str): e.g., "Class A".
  - [Selected Lanes] (list[str]): e.g., ["Lane1", "Lane2"].
- Case 2: Auto Live Load (opt_auto_ll=True) Each inner list must contain 5-6 items: [Scale Factor, Vehicle Class I, Vehicle Class II, Footway Vehicle, [Carriageway Lanes], [Footway Lanes]]
  - Vehicle Class I/II (str): Primary/secondary vehicle names. Use "" for none.
  - Footway Vehicle (str): Footway vehicle name. Use "" for none.
  - [Footway Lanes] (list[str], optional): Lanes for footway load.
- Case 3: Permit Vehicle (opt_lc_for_permit=True) This parameter is not used. Use the permit_vehicle_id, ref_lane_id, etc., parameters instead.
scale_factor (list, optional): A list of 4 numbers for the Multiple Presence Factor. Defaults to [1, 0.9, 0.8, 0.8].
permit_vehicle_id (int, optional): The ID of the permit vehicle. Required for permit cases.
ref_lane_id (int, optional): The reference lane ID. Required for permit cases.
eccentricity (float, optional): Eccentricity for the permit vehicle. Required for permit cases.
permit_scale_factor (float, optional): Scale factor for the permit vehicle. Required for permit cases.

Eurocode

MovingLoad.Case.Eurocode(name, load_model, use_optimization=False, id=None, sub_load_items=None, **kwargs)

Creates a moving load case according to Eurocode standards. It supports General Load and Moving Load Optimization modes across various load models.

Parameters

name (str): The name of the load case.
load_model (int): The Eurocode Load Model type (1-5).
use_optimization (bool, optional): Set to True for "Moving Load Optimization". Defaults to False.
id (int, optional): A unique integer ID for the case. Auto-assigned if None.
sub_load_items (list): A simplified list for defining the load case details. The format varies significantly based on load_model and use_optimization.
**kwargs: Additional individual parameters can be passed

`sub_load_items` Format Details

General Load (use_optimization=False)
- load_model = 1: [opt_leading, vhl_name1, vhl_name2, selected_lanes, remaining_area_lanes, footway_lanes]
  - opt_leading (bool): True for leading vehicle.
  - vhl_name1/vhl_name2 (str): Vehicle names.
  - selected_lanes (list[str]): Lanes for tandem system.
  - remaining_area_lanes (list[str]): Lanes for UDL.
  - footway_lanes (list[str]): Lanes for footway load.
- load_model = 2: [opt_leading, opt_comb, [(name, sf, min_L, max_L, [lanes]), ...]]
  - opt_comb (int): Combination option.
  - The inner list defines sub-loads with: name (str), sf (float), min_L/max_L (int), and lanes (list[str]).
- load_model = 3: [opt_leading, vhl_name1, vhl_name2, selected_lanes, remaining_area_lanes]
- load_model = 4: [opt_leading, vhl_name1, vhl_name2, selected_lanes, remaining_area_lanes, straddling_lanes]
  - straddling_lanes (list[dict]): e.g., [{'NAME1': 'Lane1', 'NAME2': 'Lane2'}].
- load_model = 5 (Railway): [opt_psi, opt_comb, [sf1,sf2,sf3], [mf1,mf2,mf3], [(name, sf, min_L, max_L, [lanes]), ...]]
  - opt_psi (bool): True to use psi factors.
  - [sf1,sf2,sf3] (list[float]): Scale factors.
  - [mf1,mf2,mf3] (list[float]): Multi-presence factors.
Moving Load Optimization (use_optimization=True)
- load_model = 1 or 3: [opt_leading, vhl_name1, vhl_name2, min_dist, opt_lane, loaded_lanes, [selected_lanes]]
  - min_dist (float): Minimum vehicle distance.
  - opt_lane (str): Name of the optimization lane.
  - loaded_lanes (int): Number of loaded lanes.
- load_model = 2: [opt_leading, opt_comb, min_dist, opt_lane, min_v, max_v, [(name, sf), ...]]
  - min_v/max_v (int): Min/max number of vehicles.
  - The inner list defines vehicles with name (str) and sf (float).
- load_model = 4: [opt_leading, vhl_name1, vhl_name2, min_dist, opt_lane, loaded_lanes, [selected_lanes], [straddling_lanes]]
- load_model = 5 (Railway): [opt_psi, opt_comb, [sf1,sf2,sf3], [mf1,mf2,mf3], min_dist, opt_lane, min_v, max_v, [(name, sf), ...]]

Class Methods

create

Creates all defined moving load cases in the Midas Civil model.

# Define cases first
MovingLoad.Case.India(...)
MovingLoad.Case.Eurocode(...)
# Then create them in the model
MovingLoad.Case.create()

json

Returns a JSON representation of all defined load cases.

case_json = MovingLoad.Case.json()
print(case_json)

get

Retrieves all moving load case data from the current Midas Civil model.

case_data = MovingLoad.Case.get()
print(case_data)

sync

Synchronizes load cases from Midas Civil back to the Python script, overwriting any local definitions.

MovingLoad.Case.sync()
# See the synced cases
for case in MovingLoad.Case.cases:
    print(f"Synced Case: {case.params['LCNAME']}")

delete

Deletes all moving load cases from the Midas Civil model.

MovingLoad.Case.delete()

Examples

Creating Indian Standard Cases

# Set Indian standards
MovingLoad.Code("INDIA")

# Example 1: General Load Case
MovingLoad.Case.India(
    id=1,
    name="General_IRC_Loading",
    num_loaded_lanes=2,
    opt_auto_ll=False,
    sub_load_items=[
        [1.0, 1, 2, "Class A", ["Lane1", "Lane2"]],
        [0.8, 1, 1, "Class 70R", ["Lane1"]]
    ]
)

# Example 2: Auto Live Load Combination
MovingLoad.Case.India(
    id=2,
    name="Auto_Combination",
    num_loaded_lanes=2,
    opt_auto_ll=True,
    sub_load_items=[
        [1.0, "Class A", "Class B", "Footway", ["Lane1", "Lane2"], ["Footpath1"]]
    ]
)

# Example 3: Permit Vehicle Load
MovingLoad.Case.India(
    id=3,
    name="Permit_Vehicle_Case",
    num_loaded_lanes=1,
    opt_lc_for_permit=True,
    permit_vehicle_id=5,      # Assuming a permit vehicle with ID 5 exists
    ref_lane_id=1,            # Reference lane is Lane1
    eccentricity=0.5,
    permit_scale_factor=1.1
)

# Create all defined Indian cases in Midas Civil
MovingLoad.Case.create()

Creating Eurocode Standard Cases

# Set European standards
MovingLoad.Code("EUROCODE")

# Example 1: General Load, Load Model 1
MovingLoad.Case.Eurocode(
    id=1,
    name="EC_General_LM1",
    load_model=1,
    use_optimization=False,
    sub_load_items=[
        False,                      # opt_leading
        "LM1_Vehicle",              # vhl_name1
        "",                         # vhl_name2
        ["Lane1"],                  # selected_lanes
        ["Lane2", "Lane3"],         # remaining_area_lanes
        ["Footpath1"]               # footway_lanes
    ]
)

# Example 2: General Load, Load Model 5 (Railway)
MovingLoad.Case.Eurocode(
    id=2,
    name="EC_Railway_LM5",
    load_model=5,
    use_optimization=False,
    sub_load_items=[
        False,                                  # opt_psi_factor
        0,                                      # opt_comb
        [0.8, 0.7, 0.6],                        # scale_factors
        [1.0, 1.0, 0.75],                       # multi_presence_factors
        [("LM71", 1.0, 1, 1, ["Track1"])]       # sub_load_data_list
    ]
)

# Example 3: Moving Load Optimization, Load Model 3
MovingLoad.Case.Eurocode(
    id=3,
    name="EC_Optimized_LM3",
    load_model=3,
    use_optimization=True,
    sub_load_items=[
        True,                       # opt_leading
        "SV196",                    # vhl_name1
        "",                         # vhl_name2
        15.0,                       # min_dist
        "Lane2",                    # opt_lane
        2,                          # loaded_lanes
        ["Lane1", "Lane2", "Lane3"] # selected_lanes
    ]
)

# Create all defined Eurocode cases in Midas Civil
MovingLoad.Case.create()

Moving Load Case

Constructor

Country-Specific Subclasses

India

Parameters

Eurocode

Parameters

sub_load_items Format Details

Class Methods

create

json

get

sync

delete

Examples

Creating Indian Standard Cases

Creating Eurocode Standard Cases

`sub_load_items` Format Details