Shown are the results of the modified SPM method for determining the pressure loads of seawalls by broken waves.
The formulae for the calculated parameters are shown in the lower part of the page for the purpose of clarity.
The maximum wave run-up height \( z_{A,max} \) can be freely selected. A validation in terms of the extended Hunt formula for the calculation of the wave run-up height \( z_{98} \) does not take place.
Formulae for the load case “structure seaward of the shoreline” of the modified SPM method:
Surge height \( H_{w1} = \left( 0.2 + 0.58 \cdot \frac{h_{w1}}{d_b} \right) \cdot H_b \),
Surge velocity \( v_{w1} = c_b = \sqrt{g \cdot d_b} \),
Surge pressure \( p_{surge} = \rho_w \cdot \frac{v_{w1}^2}{2} \),
Hydrostatic wave pressure \( p_w = \rho_w \cdot g \cdot H_{w1} \),
Hydrostatic pressure \( p_{stat} = \rho_w \cdot g \cdot h_{w1} \),
Surge force \( F_{surge} = \frac{1}{2} \cdot \rho_w \cdot g \cdot d_b \cdot H_{w1} \),
Hydrostatic wave force (over SWL) \( F_{wo} = \frac{1}{2} \cdot \rho_w \cdot g \cdot H_{w1}^2 \),
Hydrostatic force \( F_{stat} = \frac{1}{2} \cdot \rho_w \cdot g \cdot h_{w1}^2 \),
Hydrostatic wave force (under SWL) \( F_{wu} = \rho_w \cdot g \cdot H_{w1} \cdot h_{w1} \).
Formulae for the load case “structure landward of the shoreline” of the modified SPM method:
Surge height \( H_{w2} = 0.2 \cdot H_b \cdot \left( 1 - \frac{x_2}{x_A} \right) \),
Surge velocity \( v_{w2} = c_b = \sqrt{g \cdot d_b} \cdot \left( 1 - \frac{x_2}{x_A} \right) \),
Surge pressure \( p_{surge} = \rho_w \cdot \frac{v_{w2}^2}{2} \),
Hydrostatic pressure \( p_w = \rho_w \cdot g \cdot H_{w2} \),
Surge force \( F_{surge} = \frac{1}{2} \cdot \rho_w \cdot g \cdot d_b \cdot H_{w2} \cdot \left( 1 - \frac{x_2}{x_A} \right)^2 \),
Hydrostatic wave force (over SWL) \( F_{wo} = \frac{1}{2} \cdot \rho_w \cdot g \cdot H_{w2}^2 \).
The following also applies: Sea water density \( \rho_w = 1025 \frac{kg}{m^3} \), and acceleration due to gravity \( g = 9.81 \frac{m}{s^2} \).
The field of Loads on Structures is part of the module Coastal Dynamics and Engineering Design within the specialization Coastal and Ocean Engineering of the master programmes Civil and Environmental Engineering.