中国西藏察达沟谷内存在有大量冰碛土，随着西部大开发的进行，该地区将有众多基础性工程建设于该冰碛层冻土地基上。为探究该地区冰碛土冻结深度和冻胀变形的影响因素，通过正交设计，在室内开展开放系统下多因素多水平单向冻结试验，研究了开放系统单向冻结下各因素对冰碛土冻结深度和冻胀变形的影响及显著性大小，同时对冻结后土体不同高度水分重分布进行分析，并给出冻结深度和冻胀变形的多元回归方程。研究表明：对冻结深度和冻胀变形影响最为显著的因素分别是冻结端温度和初始体积含水率。各因素对冻结深度显著性影响大小排序为：冻结端温度>冻结时间>冻结端降温速率>初始体积含水率>压实度；对冻胀变形影响大小排序为：初始体积含水率>冻结端温度>压实度>冻结时间>冻结端降温速率；当冷端温度低、冻结时间长时，冻结锋面上方3~8 cm处存在冻结缘，此处为水分迁移和水冰相变的关键区域，会作为蓄水带进一步加剧土体的冻胀；根据正交试验结果，建立了可有效预测该地区冰碛土在多因素影响下的冻结深度和冻胀变形的多元回归方程。研究结果对相关地区冰碛土工程安全性评价与防冻害设计具有一定参考价值。

The presence of large amounts of moraine soil in the Chada Gully of Xizang， China， with the development of the western regions， there will be numerous infrastructure projects built on moraine frozen soil foundations. To investigate the influence factors of frost depth and frost heave deformation of moraine soil in this area， carry out multi-factor and multi-level unidirectional freezing tests under the open system indoors through orthogonal design， having investigated the effects and magnitude of the significance of different factors on frost depth and frost deformation of moraine soils under unidirectional freezing conditions in an open system， at the same time， analyzed the redistribution of moisture in the moraine soil at different heights after freezing， and established the multivariate linear regression equations of multi-factors with the frost depth and frost heave deformation. The study shows that the most significant factors affecting frost depth and frost heave deformation are freezing side temperature and initial volumetric water content， respectively. The significant influence of each factor on frost depth is as follows： freezing side temperature>freezing time>freezing side cooling rate>initial volumetric water content>compaction， of which the freezing side temperature （negative temperature） and freezing time are positively correlated with the frost depth， and the other three factors have a small influence on it. The influence on frost heave deformation is as follows： initial volumetric water content>freezing side temperature>compaction>freezing time>freezing side cooling rate， and initial water content is positively correlated with the freezing side temperature and the frost heave deformation， compaction is negatively correlated with it， and the cooling rate and freezing time have less influence on it. Due to the large pores of the solid particles of the moraine soil， the freezing process moisture continues to migrate to the cold end， and free water and gaseous water form a poly-ice layer at the cold end. When the temperature of the cold end is low and the freezing time is long， there exists a freezing edge 3~8 cm above the freezing front， the soils here are saturated， with large amounts of free ice and free water， which is the key area for water migration and water-ice phase transition， when the bottom of the soil body is recharged， this area acts as a water storage zone further exacerbating the frost heave of the soil body. According to the orthogonal test results， a multiple linear regression equation was established to effectively predict the frost depth and frost heave deformation of the moraine soil in this area under the influence of multiple factors， and this equation can be utilized in the engineering field to quickly classify the freezing grade of the soil body. The results of the study have certain reference values for the safety evaluation and anti-freezing design of moraine soil projects in the relevant area.