A high-speed debris flow sliding into a reservoir can cause a huge disaster. Consequently, predicting landslide movement accurately and its potential interaction with water is crucial. This paper developed a computational model based on a two–layer two–phase material point method (MPM) to simulate surge waves generated by granular landslides on an erodible slope. By comparing granular landslide on a rigid and erodible slope, the effect of the slope erodibility on the process of landslide movement and the waves generated is investigated. The model takes full account of the large deformations, fluidisation and settlement of granular material in soil–water interactions. The numerical model is validated by comparing the simulated results with experimental data. The influences of internal friction angle, density, elastic modulus, Poisson ratio and dilatancy angle on wave height are also studied. The validated model was then used to investigate the surge waves generated by dry and saturated granules sliding along a rigid and erodible slope. The results show that both the erodible slope and saturated granular slide can increase the first wave crest height generated by the landslide.

Underwater jet scouring is an efficient, flexible underwater dredging technique, yet its complex physical mechanisms and dynamic evolution hinder dredging effectiveness evaluation. Existing studies mostly use empirical formulas and neglect the sediment properties’ influence on scour holes. This study integrates numerical simulation, theoretical derivation, and sediment characteristics to develop a universal model for efficiently predicting underwater jet scour hole morphology, overcoming existing models’ limitations of over-simplifying complex physics and insufficient experimental data alignment. Using CFD–DEM coupling to simulate scouring, it correlates key physical parameters (average/maximum shear rate, average/maximum shear velocity) with jet characteristics (nozzle diameter, velocity, distance) via theoretical derivation and simplifications, validated using multi-condition simulation data. Comparative analysis shows maximum relative errors of 13% for depth and 7% for width, confirming the engineering applicability in scour hole prediction.

Existing bollard force measurement methods have not yet been able to realise simple, accurate, and efficient measurements of the bollard force of a single ship’s cable. In this paper, an experimental study on the measurement of ship bollard force is carried out with reference to the calculation method of measuring the cable force of a diagonal cable. Based on the fundamental frequency method and the frequency difference method, a new comprehensive method is proposed to detect the fundamental frequency of cable vibration. A study on the identification of the cable condition based on the measured vibration data is also carried out. Experimental studies on the error rate of different data acquisition positions, excitation methods, excitation positions, wetted cables, different temperatures, and other influencing factors were conducted, and a new excitation method based on environmental excitation and artificial excitation was proposed. By analysing the calculated values of the vibration frequency method and the tensile values of the prototype test platform, it is concluded that the data acquisition position, excitation position, and excitation method have a small influence on the measured value of the ship’s bollard force, and the range of the error rate increases by about 1.5% under the wetting of the cable and ±2% under the low temperature (2 °C), with the integrated error range of −5% to 4%, and the error rate can satisfy the normal distribution well, and the measurement accuracy is corrected by correcting the length of the cable. The measurement accuracy is corrected by correcting the cable length. It is proved that the method has strong feasibility and applicability, and can effectively realise simple, accurate, and efficient measurement of ship bollard force.