# Study on the Steepness of Landslide-Induced Wave and Nonlinear Motion of Container Ships
## 1 Introduction  
The Three Gorges Reservoir area along the Yangtze river is located in the Sichuan basin and the middle-lower Yangtze plain area. The length of the trunk is about 690 km. It is part of the city of Chongqing and extends down to the Hubei Yichang which includes 22 administrative areas and accounts for 175 m of water dispatching work. The reservoir area is a mountainous steep slope, rainfall is abundant, and it is a typical mountainous river reservoir. The terrain of the reservoir area is complex, and the soil or rock mass on the bank slope has been affected by river scour, groundwater erosion, water level fluctuation, wind and wave impact, crustal activity, dry and wet alternations, etc. for a long time. Due to gravity, the soil or rock mass will slide downward dispersing along the weak surface. After the potentially dangerous rock mass enters the river, the water level of the river, the velocity of water in the river, and the shape of the river section can change. There may be bad flow patterns, such as whirlpool and backflow, in the river, which will affect the normal navigation of a ship. Serious landslide and surge disaster accidents can make the ship capsize instantly, which will cause closure and navigation restriction of the accident area in the Three Gorges Reservoir. Landslide-induced surge has the characteristics of a wide influence area, a large disaster area, and a high damage degree. Many studies have been conducted on landslide-induced surge physical model experiments, ship nonlinear motion, and wave steepness characteristics. By means of numerical simulation, experts have simulated landslide-induced surge generated impulse waves and analyzed the deformation of the sliding mass in Newtonian and non-Newtonian fluids, [PERSON] [1], [PERSON] [2], and [PERSON] [3] applied the WC-MPS(Weakly Compressible Moving-Particle Semi-Implicit), rigorous finite volume and ISPH (Incompressible Smoothed ParticleHydrodynamics) modelling separately. Through orthogonal experiments with physical models, scholars have studied the wave parameters, propagation law, attenuation coefficient, and other parameters of landslide-induced surges, [PERSON] [4], [PERSON] [5], and [PERSON] [6] focused on shallow water, complex topography, and non-hydrostatic separately. Recent research efforts into 2D experiment trails. [PERSON] [7] performed preliminary experiments with a falling block and a wedge block with rollers to reduce friction on a 10\({}^{\circ}\) incline plane. The wave generation between the two methods differs because the sliding wedge does not produce the previously noted reverse separation vortex. [PERSON] et al. [8] performed experiments on submarine landslides using a semi-ellipsoid and compared the experimental results to the depth-averaged nonlinear shallow water wave equations. [PERSON] et al. [9] studied submarine landslides by sliding a rigid semi-ellipsoid down a 15\({}^{\circ}\) incline in a 14.67 m long, 0.25 m wide, and 0.505 m deep basin. Extensive efforts have been made to investigate 3D experiment trails. [PERSON] et al. [10] performed a 3D block slide that was released at the end of the basin adjacent to the side wall assuming symmetry of the wave propagation. [PERSON] et al. [11] performed a 3D block landslide experiment to compare the wave characteristics. The 3D experiment trails were conducted in a 2.1 m long, 2.0 m wide, and 0.2-0.4 deep basin. Some experts, such as [PERSON] [12], [PERSON] [13], and [PERSON] [14], have studied the movement of ships on the earthquake-induced tsunami flow by writing programs and model tests. Some experts have studied the nonlinear motion and load changes of the ship, such as [PERSON] [15], [PERSON] [16], [PERSON] [17], [PERSON] [18], [PERSON] [19], and [PERSON] [20]. [PERSON] [21] compared numerical and experimental results of nonlinear wave-induced vertical ship motions and loads.