Abstract: The hollow cone-shaped foundation is an innovative foundation for onshore wind turbines. Model tests were carried out to investigate the influences of foundation sizes and loading eccentricity on the bearing behavior and earth pressure distribution along the foundation embedded depth under monotonic horizontal loading. Results show that the horizontal bearing capacity of the cone-shaped foundation increases with the increase in the diameter of the foundation and the decrease in the loading eccentricity. When the normalized loading eccentricity, (H is the loading eccentricity and is the diameter of the foundation top plate), increases from 0.5 to 1.0, the bearing capacity decreases by approximately 43%. When the ratio of the base plate diameter to the top plate diameter of the cone-shaped foundation is higher than 0.28, the bearing capacity of the cone-shaped foundation is larger than that of the regular circular gravity-based foundation under the same top plate diameter and foundation height. During horizontal loading, the cone-shaped foundation rotates about the rotation center. The rotation center moves downwards and forwards with the increase in horizontal loading, and then tends to be a stable position. The sand in front of the foundation is in the passive earth pressure zone. The size of the passive earth pressure zone decreases with the increase in the horizontal load. A method of predicting the effective area between the foundation and the sand is proposed in terms of the force equilibrium. The effective area predicted using the proposed method agrees well with the model test results. The error between the calculated result and the test result is 4.5%.

Key words: hollow cone-shaped foundation, model tests, horizontal bearing capacity, rotation center, earth pressure