civil-engineering

## What I do - Design structural systems for buildings and infrastructure - Perform geotechnical analysis and foundation design - Plan and design transportation systems - Design water resources and hydraulic systems - Manage construction projects and specifications ## When to use me - When designing buildings, bridges, or infrastructure - When analyzing soil and foundation conditions - When planning roads, railways, or airports - When designing water supply or drainage systems - When preparing construction documents and specifications ## Key Concepts ### Structural Analysis ```python # Basic structural analysis class StructuralAnalysis: def beam_stress(self, M, y, I): """Bending stress""" return M * y / I def beam_deflection(self, P, L, E, I): """Simply supported beam, point load at center""" return P * L**3 / (48 * E * I) def column_buckling(self, L, E, I): """Euler buckling load""" # P_cr = π²EI/L² return (np.pi**2 * E * I) / L**2 def shear_stress(self, V, Q, I, t): """Shear stress in beams""" return V * Q / (I * t) ``` ### Load Types | Load Type | Symbol | Description | |-----------|--------|-------------| | Dead Load | DL | Self-weight of structure | | Live Load | LL | Occupancy/usage loads | | Wind Load | WL | Wind pressure on structure | | Seismic | EL | Earthquake forces | | Snow | SL | Snow accumulation | | Rain | RL | Ponding on flat roofs | ### Foundation Design ```python # Shallow foundation class FoundationDesign: @staticmethod def bearing_capacity(c, phi, gamma, D_f, B): """Terzaghi's bearing capacity""" # q_ult = cN_c + γD_fN_q + 0.5γBN_γ N_q = np.exp(2 * np.pi * np.tan(np.radians(phi))) * np.tan(np.pi/4 + phi/2)**2 N_c = (N_q - 1) / (2 * np.tan(np.radians(phi))) N_gamma = (N_q - 1) * np.tan(1.4 * phi) return c * N_c + gamma * D_f * N_q + 0.5 * gamma * B * N_gamma @staticmethod def settlement(Es, mu, q, B): """Immediate settlement (elastic)""" # s_i = (qB(1-μ²) / Es) × I return (q * B * (1 - mu**2) / Es) * 1.5 ``` ### Concrete Design ```python # Reinforced concrete class ConcreteDesign: @staticmethod def steel_area(f_strength, d, As_required): """Calculate reinforcement""" return As_required @staticmethod def crack_width(f_s, z, A): """Calculate crack width""" # w = f_s × A / (0.6 × Es × z) return f_s * A / (0.6 * 200000 * z) @staticmethod def deflection(I, M, E): """Calculate deflection""" return 5 * M * 12**2 / (384 * E * I) ``` ### Geotechnical Parameters | Soil Type | γ (kN/m³) | c (kPa) | φ (°) | E (MPa) | |-----------|-----------|---------|-------|---------| | Sand (dense) | 18-20 | 0 | 35-40 | 50-80 | | Sand (loose) | 15-17 | 0 | 30-35 | 20-40 | | Clay (stiff) | 18-20 | 50-100 | 20-25 | 20-50 | | Clay (soft) | 15-17 | 10-25 | 10-15 | 2-10 | | Gravel | 19-22 | 0 | 35-45 | 100-200 | ### Transportation Design ```python # Pavement design (AASHTO) class PavementDesign: @staticmethod def structural_number(W_18, R, S, Z): """Calculate required SN""" # Logarithmic relationship return (W_18 - 7.35*np.log10(R+1) + 0.2 - 9.36*np.log10(S+1) + 8.27*Z) / (0.4 + 1094/(S+1)**2.2) ``` ### Common Codes and Standards - **ACI**: American Concrete Institute - **AISC**: American Institute of Steel Construction - **ASCE**: American Society of Civil Engineers - **IBC**: International Building Code - **AASHTO**: American Association of State Highway Officials