4d-simulation

4D Simulation for Construction

Overview

Based on DDC methodology (Chapter 3.3), this skill implements 4D BIM simulations - linking 3D model elements to the 4th dimension: time. Visualize construction sequences, detect scheduling conflicts, and optimize work phasing.

Book Reference: "4D, 6D-8D и расчет CO2" / "4D-8D BIM and CO2 Calculation"

"4D моделирование позволяет визуализировать последовательность строительства и выявлять конфликты на этапе планирования." — DDC Book, Chapter 3.3

Quick Start

import pandas as pd
from datetime import datetime, timedelta

# BIM elements with schedule data
elements = pd.DataFrame({
    'ElementId': ['E001', 'E002', 'E003', 'E004'],
    'Category': ['Foundation', 'Column', 'Beam', 'Slab'],
    'Level': ['Level 0', 'Level 1', 'Level 1', 'Level 1'],
    'Start_Date': ['2024-01-01', '2024-01-15', '2024-02-01', '2024-02-15'],
    'End_Date': ['2024-01-14', '2024-01-31', '2024-02-14', '2024-02-28'],
    'Phase': ['Structure', 'Structure', 'Structure', 'Structure']
})

elements['Start_Date'] = pd.to_datetime(elements['Start_Date'])
elements['End_Date'] = pd.to_datetime(elements['End_Date'])
elements['Duration_Days'] = (elements['End_Date'] - elements['Start_Date']).dt.days

# Get elements active on a specific date
target_date = pd.to_datetime('2024-01-20')
active_elements = elements[
    (elements['Start_Date'] <= target_date) &
    (elements['End_Date'] >= target_date)
]
print(f"Elements under construction on {target_date.date()}:")
print(active_elements[['ElementId', 'Category']])

4D Data Model

Schedule-Element Linking

import pandas as pd
import numpy as np
from datetime import datetime, timedelta
from typing import List, Dict, Optional

class ScheduleElementLinker:
    """Link BIM elements to schedule activities"""

    def __init__(self, elements_df: pd.DataFrame, schedule_df: pd.DataFrame):
        self.elements = elements_df.copy()
        self.schedule = schedule_df.copy()
        self.links = pd.DataFrame()

    def auto_link_by_category(self, mapping: Dict[str, str]):
        """Auto-link elements to activities by category mapping

        Args:
            mapping: Dict mapping element categories to activity names
                     e.g., {'Wall': 'Structural Walls', 'Slab': 'Floor Construction'}
        """
        links = []

        for category, activity_name in mapping.items():
            # Find elements of this category
            category_elements = self.elements[
                self.elements['Category'] == category
            ]['ElementId'].tolist()

            # Find matching activity
            activity = self.schedule[
                self.schedule['Activity'].str.contains(activity_name, case=False)
            ]

            if not activity.empty and category_elements:
                for elem_id in category_elements:
                    links.append({
                        'ElementId': elem_id,
                        'ActivityId': activity.iloc[0]['ActivityId'],
                        'Activity': activity.iloc[0]['Activity'],
                        'Start_Date': activity.iloc[0]['Start_Date'],
                        'End_Date': activity.iloc[0]['End_Date']
                    })

        self.links = pd.DataFrame(links)
        return self.links

    def auto_link_by_level(self):
        """Auto-link elements based on level and construction sequence"""
        # Get unique levels in order
        levels = sorted(self.elements['Level'].unique())

        links = []
        for i, level in enumerate(levels):
            level_elements = self.elements[self.elements['Level'] == level]

            # Find activity for this level
            level_activity = self.schedule[
                self.schedule['Activity'].str.contains(level, case=False)
            ]

            if not level_activity.empty:
                for _, elem in level_elements.iterrows():
                    links.append({
                        'ElementId': elem['ElementId'],
                        'ActivityId': level_activity.iloc[0]['ActivityId'],
                        'Activity': level_activity.iloc[0]['Activity'],
                        'Start_Date': level_activity.iloc[0]['Start_Date'],
                        'End_Date': level_activity.iloc[0]['End_Date']
                    })

        self.links = pd.DataFrame(links)
        return self.links

    def manual_link(self, element_id: str, activity_id: str):
        """Manually link element to activity"""
        element = self.elements[self.elements['ElementId'] == element_id]
        activity = self.schedule[self.schedule['ActivityId'] == activity_id]

        if element.empty or activity.empty:
            raise ValueError("Element or activity not found")

        new_link = pd.DataFrame([{
            'ElementId': element_id,
            'ActivityId': activity_id,
            'Activity': activity.iloc[0]['Activity'],
            'Start_Date': activity.iloc[0]['Start_Date'],
            'End_Date': activity.iloc[0]['End_Date']
        }])

        self.links = pd.concat([self.links, new_link], ignore_index=True)
        return self.links

    def get_linked_elements(self):
        """Get elements with schedule data"""
        return self.elements.merge(
            self.links[['ElementId', 'ActivityId', 'Start_Date', 'End_Date']],
            on='ElementId',
            how='left'
        )