Shared anchor foundations experience loads from various directions throughout their operational lifespan. As a result of environmental loads or the possibility of anchor chain failures, the loading direction of the shared foundation may alter, affecting its normal functionality. This study investigates the bearing capacity of the shared caisson in sand using an advanced model and numerical methods under multidirectional loading. Moreover, the research investigates soil responses to clarify the mechanisms governing bearing capacity. The study delves into factors such as load angles, sand density, and previous load magnitudes to comprehend their impact on the bearing capacity of shared caissons. The findings suggest that subsequent loading on dense soil enhances bearing capacity, whereas loading on loose soil reduces it. Key factors influencing the shared caisson's bearing capacity include plastic deformation of the surrounding soil and density changes resulting from previous loads. A coefficient was proposed for designing the shared caisson, taking into account multidirectional loads, thereby providing insights for future shared anchor foundation designs.