吸力桶形基础沉贯与所施加的吸力密切相关，吸力值设置太小会导致吸力基础沉贯速度过慢，施工效益降低；吸力值设置太大将产生较高的桶内土塞，吸力基础下沉不到预定位置，从而使其承载力达不到设计要求，或引起砂土地基产生管涌破坏，因此必须确定合理的吸力值以满足工程建设需要。通过吸力桶形基础的静力平衡条件获得了沉贯所需最小吸力值；根据桶壁底部土体破坏特性，并依据Hencky应力方程建立了桶壁内、外侧土体之间的有效应力表达式，求解了土塞加速上升时的临界吸力值；基于吸力桶形基础内部砂土的管涌破坏机制确定了最大吸力值，结合最大和最小吸力的理论公式得到了吸力桶形基础的最大沉贯深度。最后，采用实例数据验证了所提出的最小、临界和最大吸力理论公式的合理性。

Penetration of the suction caisson closely depends on the suction pressure. If the magnitude of suction is set to be smaller, it will lead to a lower penetration velocity and increasing construction costs. The soil plug rises higher otherwise. Thus, the suction caisson cannot reach the desired depth, resulting in either insufficient bearing capacity for the requirements of foundation design, or the failure of sand foundation due to piping. The aim of the paper is to determine a reasonable suction range to meet requirements of engineering practice. The minimum suction is determined by using the static equilibrium method. The critical value of suction is obtained by the formulation of the effective stresses on the inside and outside of the bucket wall in terms of the Hencky’s stress equation. The maximum suction is obtained by using the mechanism of sand piping inside bucket. In addition, the maximum penetration depth of the caisson is determined in terms of the maximum and minimum suctions. Finally, the proposed calculation of suction are verified by the published data, and they have a very good agreement.