Civil, Structural, Geotechnical & Hydraulic Engineering Hub
Rigorous solvers for beam elastic deflection, Manning open channel flow, reinforced concrete rebar ratio, retaining wall lateral earth pressure, and column buckling.
Beam Deflection & Maximum Bending Moment Calculator
Calculate maximum bending moment, shear force, and mid-span elastic deflection for simply supported and cantilever steel or wood structural beams.
Soil Compaction Dry Density & Optimum Moisture (Proctor Test)
Calculate soil dry density from wet bulk density and moisture content, and determine relative compaction percentage against ASTM D698 / D1557 Proctor maximums.
Darcy-Weisbach Pipe Friction Head Loss & Pressure Drop Calculator
Calculate friction head loss (h_f in feet), pressure drop (psi), and Reynolds number (laminar vs turbulent) for pressurized fluid flow in commercial pipe networks.
Manning's Open Channel Flow Velocity & Discharge Capacity Calculator
Calculate discharge capacity in CFS, flow velocity in fps, and hydraulic radius for trapezoidal, rectangular, and circular open channels.
ASCE 7 Wind Load Velocity Pressure on Building Envelopes Calculator
Calculate design wind velocity pressure (q_z in PSF) based on basic wind speed, surface roughness exposure category (B, C, D), and mean roof height (ASCE 7-16 / 7-22).
Reinforced Concrete Slab One-Way & Two-Way Punching Shear Capacity (ACI 318)
Calculate nominal concrete shear strength (V_c), critical shear perimeter (b_0), and punching shear failure capacity around interior column supports.
Earthwork Cut and Fill Volume Calculator (Average End Area Method)
Calculate earthwork excavation cut and fill volumes in cubic yards between station cross-sections using the standard civil Average End Area Method.
Retaining Wall Rankine Lateral Earth Pressure (Active & Passive) Calculator
Calculate active and passive earth pressure coefficients (Ka, Kp), total lateral thrust force, and overturning moment for retaining wall design.
Stormwater Runoff Peak Discharge Calculator (Rational Method Q = CยทIยทA)
Calculate watershed peak stormwater runoff discharge in cubic feet per second (CFS) for drainage culverts and retention detention basin sizing.
Asphalt Pavement Structural Number & AASHTO ESAL Design Life Calculator
Calculate flexible asphalt pavement Structural Number (SN), layer thicknesses (surface, base, subbase), and allowable 18-kip Equivalent Single Axle Loads (ESAL).
Steel Column Euler Critical Buckling Load & Slenderness Ratio Calculator
Calculate Euler critical elastic buckling load (P_cr in kips), slenderness ratio (KL/r), and critical buckling stress for structural columns.
Shallow Foundation Bearing Capacity Calculator (Terzaghi Equation)
Calculate ultimate and allowable soil bearing capacity (q_ult, q_all in PSF) for strip and square shallow footings using Terzaghi's bearing capacity factors.
Highway Culvert Hydraulics (Inlet vs Outlet Control Headwater Depth)
Calculate culvert headwater depth (HW/D ratio), flow control regime (inlet control vs outlet control), and discharge capacity (FHWA HDS-5 standards).
Stormwater Detention Basin Storage Volume & Settling Inflow Calculator
Calculate required active flood retention storage volume (acre-feet and cubic feet) and orifice release diameter for post-development stormwater mitigation.
Truss Member Axial Tension & Compression (Method of Joints) Calculator
Calculate internal axial forces (tension or compression in kips) in pin-jointed Pratt and Warren truss members using static equilibrium.
Concrete Curing Compressive Strength Maturity Index (Nurse-Saul Method)
Calculate Nurse-Saul Temperature-Time Maturity Index (TTF in ยฐC-hours) to predict in-place concrete early compressive strength for formwork stripping (ASTM C1074).
Water Hammer Joukowsky Shockwave Pressure Surge & Wave Speed Calculator
Calculate rapid valve closure acoustic pressure spike (Joukowsky equation ฮP = ฯยทcยทฮv) and acoustic wave speed in elastic pipe walls.
Soil Slope Stability Safety Factor (Ordinary / Bishop Method)
Calculate factor of safety against deep rotational circular slip failure in earthen embankments, highway cuts, and hillside slopes.
Geotextile Fabric Tensile Modulus for Subgrade Stabilization Calculator
Calculate aggregate base reduction, subgrade California Bearing Ratio (CBR) reinforcement, and tensile modulus for roadbed geotextiles (FHWA design).
Seismic Equivalent Lateral Force Base Shear Calculator (ASCE 7 / IBC)
Calculate total seismic design base shear (V = Cs ยท W) and seismic response coefficient (Cs) compliant with ASCE 7-16 and International Building Code.
Wastewater BOD Removal Efficiency & Aeration Tank Sizing Calculator
Calculate municipal and industrial wastewater Biochemical Oxygen Demand (BODโ ) removal efficiency, hydraulic retention time (HRT), and aeration basin volume.
Deep Foundation Driven Pile Static Axial Skin Friction & End Bearing Capacity
Calculate ultimate and allowable axial compressive load capacity for driven steel H-piles and concrete friction piles (Q_ult = Q_skin + Q_tip).
Pre-Stressed Concrete Post-Tension Tendon Elongation & Friction Loss Calculator
Calculate theoretical tendon elongation (ฮL in inches), jack jacking force, and curvature wobble friction losses (PTI / ACI 318 standards).
Bridge Superstructure Thermal Expansion & Expansion Joint Sizing Calculator
Calculate total thermal movement (expansion and contraction ฮL in inches) and select bridge expansion joint seals (strip seal, modular joint) under AASHTO LRFD.
Roadway Horizontal Alignment Minimum Curve Radius & Superelevation Calculator
Calculate minimum curve radius (R_min in feet), maximum design superelevation banking (e_max %), and side friction factors compliant with AASHTO Green Book.