为解决全断面砂卵石地层地下工程的地下水控制问题，提出盆形冻结止水技术。首先，采用三轴力学试验研究冻结砂卵石的压缩力学特性和蠕变力学特性；然后，采用大尺度物理模型试验和数值模拟方法研究盆形冻结的温度场扩展规律，并根据研究结果进一步提出盆形冻结积极冻结期的群孔布置技术和维护冻结期的精细化控制技术。结果表明： 1）低围压（小于3 MPa）条件下，三轴抗压强度与围压呈正线性相关，然后围压继续增大时，强度基本不变； 基于损伤理论建立冻结砂卵石全过程蠕变模型。 2）荷载对冻胀率及融沉系数影响最大，细粒土质量分数次之，原状饱和砂卵石是不冻胀材料，并由此建立饱和砂卵石冻胀率及融沉系数三维预测模型。 3）基于大型物理模型试验及数值模拟结果，盆形冻结可以在地下水渗流条件下形成完整的盆形结构，起到有效止水的效果。 4）盆底冻结管在冻结过程中表现出与单管冻结迥异的“群孔效应”，根据试验结果提出包含冻结管间距、土体导热系数、渗流速度3因素的积极冻结期冻结管合理间距的确定与布置技术。 5）为节约维护冻结期的能源，提出隔排切割冻结管、仅保留盆壁冻结管2种维护形式以对冻结区域进行精细化控制，经过分析，2种方式均可以有效满足盆形结构维护期的冷量供给，保持完整的盆形形态。

A basinshaped freezing waterstopping technology is proposed to control groundwater in underground engineering of fullsection sandy gravel strata. First, the compression and creep mechanical properties of the frozen sandy gravel are examined using a triaxial test. Second, the developing pattern of the temperature field in basinshaped freezing is investigated using largescale physical model tests and numerical simulations. Finally, a layout method for the freezinghole group during the freezing period and a precision control technology during the maintenance period are proposed. The following conclusions are obtained: (1) The triaxial compressive strength of the sandy gravel is positively and linearly correlated to the confining pressure under a confining pressure of less than 3 MPa, but remains unchanged when the confining pressure is increased. The whole process creep model of frozen sandy gravel is established on the basis of the damage theory. (2) Load has the greatest influence on the frost heave rate and melt sink coefficient, followed by fine soil content. The original saturated sandy gravel is a nonfrost heave material, and a threedimensional prediction model for the frost heave rate and melt sink coefficient of saturated sandy gravel is established. (3) The results of largescale physical model experiments and numerical simulations indicate that basinshaped freezing can form a complete basinshaped waterproof structure under groundwater seepage conditions, effectively stopping the water. (4) During the freezing process, the bottom freezing pipes exhibit a "superposition effect", which is completely different from that of a single pipe. A layout method for the freezing pipes during the active freezing period, including the spacing of the freezing pipes, thermal conductivity of the soil, and seepage velocity, is proposed on the basis of the experimental results. (5) To save cooling energy during the maintenance period, two schemes of freezing pipe cutting every other row and freezing pipe cutting at the bottom are proposed to finely control the freezing area.