Concrete mortar segregation during vertical pipeline gravity transportation will form a weak part in the shaft lining, which poses a challenge for deep mine shaft safety. The specific gravity difference between aggregate and slurry will cause relative motion; the relative velocity is detrimental to the mortar workability, which plays a significant role in mortar segregation. A prediction model of the relative velocity between slurry and aggregate was proposed and verified by numerical simulation results. This approach adopts the interference coefficient to revise the aggregate collision loss. The corresponding relationship among aggregate relative velocity, mortar rheological properties and particle shape was analysed to explain the mortar segregation mechanism. Segregation can be prevented by increasing the mortar viscosity and shape coefficient and decreasing the density difference and aggregate diameter to reduce the relative velocity. This work is favourable for concrete mortar quality control for gravity transportation and shaft lining construction safety.

垂直管道重力输送过程中混凝土砂浆的偏析会在竖井衬砌中形成薄弱部分，这对深部矿井竖井安全构成了挑战。骨料和泥浆之间的比重差将引起相对运动；相对速度对砂浆的可加工性有害，这在砂浆的偏析中起着重要作用。提出了砂浆与骨料之间相对速度的预测模型，并通过数值模拟结果进行了验证。该方法采用干扰系数来修正总碰撞损失。分析了骨料相对速度，砂浆流变性和颗粒形状之间的对应关系，以解释砂浆的偏析机理。可以通过提高砂浆粘度和形状系数并减小密度差和集料直径以降低相对速度来防止偏析。这项工作有利于控制重力输送和轴衬施工安全的混凝土砂浆质量。