为了探索不同气候条件下膨胀土路基的含水量、土压力、温度、竖向胀缩变形等特征参数的基本变化规律，分别选取湖南省高速公路建设中经常遇到的弱膨胀土和中等膨胀土作为实验土样，按90%的压实度填筑，在不同排水边界条件模拟路堤在4种不同气侯条件下2组膨胀土路堤模拟实验，结果表明，膨胀土路堤中含水量、土压力、温度和胀缩变形等均受大气影响，且与路堤土的类型、密实度、排水边界条件关系密切：① 埋藏较浅，含水量的变化受大气影响越大，路基中含水量越高，受气候条件影响越明显；② 膨胀土路堤中的土压力变化是膨胀土路堤中含水率和气候条件综合作用的结果；③ 对路基温度变化影响最大的是日照，其次是降雨，阴天影响最小；④ 竖向胀缩变形主要发生在路堤基顶积水阶段。因此，在具体工程建设中，防渗保湿和合理设计排水系统是防治膨胀土路基遭受破坏的关键。
In order to explore the basic laws of the characteristics parameters of expansive soil moisture, soil pressure, temperature, vertical expansion and contraction deformation in the different climatic conditions, the weak expansive soil and the medium expansive soil which frequently appears in highway construction in Hunan Province were selected as the test samples. According to 90% of the compaction degree to fill, in different drainage boundary conditions, two groups of expansive soil embank simulation experiment was taken in four different climate conditions, the results indicate that the water content, soil pressure, temperature, and swelling and shrinkage deformation of expansive soil embankment are all governed by atmospheric effects, and are close related to the embankment soil type, density, drainage boundary conditions: (1) The shallower subgrade buried, the greater impact of atmosphere on water content changes is . The higher water content, the clearer impact of climate conditions is. (2) The changes of earth pressure in expansive soil embankment are caused by the moisture content and expansive soils pressure in different climatic conditions and different moisture content. (3) The biggest infection factor is successive sunshine, followed by rain; cloudy day only has a minimal impact. (4) Vertical expansion and contraction change mainly occur in the top water phase of road embankment foundation. Thus, in specific construction projects, anti-seepage and moist maintenance and rational design of drainage system are the key technologies for the prevention and treatment of expansive soil damage
