为贯彻落实绿色发展理念,促进红层渣土资源再利用,以甘肃天水地区的红层泥岩碎屑为研究对象,开展压实泥岩碎屑试样的侧限膨胀试验,建立改进的Huder-Amberg膨胀模型,获取试样最终含水率随轴向压力变化的函数,绘制试样压缩模量随含水率增大而劣化的曲线,并基于湿度场理论提出一种分层模拟路基吸湿膨胀变形的数值计算方法。研究结果表明:①压实红层泥岩碎屑遇水仍具有较强的膨胀性,最大膨胀应力为120.0 kPa,侧限膨胀率为0.163;②外加轴向压力从最大膨胀应力值降为0时,压实泥岩碎屑试样的最终含水率从20.6%升至40.0%、压缩模量从3 605.8 kPa降至34.1 kPa;③分层确定填筑路基的湿度线膨胀系数方法,与不分层法计算相比,路基吸湿膨胀变形更大,用于工程设计更加保守和安全;④泥岩碎屑遇水产生超过相关规范要求的膨胀变形是其不宜直接作为路基填料使用的根本原因,掺入2%的水泥改性可有效解决以上问题。

To advance the concept of green development and promote the reuse of red layer residue resources, confined expansion tests were conducted on compacted red layer mudstone clast samples from the Tianshui area of Gansu Province as a research object.An improved Huder-Amberg expansion model was established to obtain the function of final moisture content varying with axial pressure and the curves of compression modulus degradation with increasing moisture content. Furthermore, a layered numerical calculation method based on humidity field theory was proposed to simulate water-induced expansion deformation in roadbeds. The findings indicate that: 1) despite compaction, the red layer mudstone clasts exhibited substantial expansion when exposed to water, reaching a maximum expansion stress of 120.0 kPa and a confined expansion ratio of 0.163. 2) As applied axial pressure decreased from the maximum expansion stress value to zero, the final moisture content of the compacted mudstone clast samples increased from 20.6% to 40.0%, concurrently with a decrease in compression modulus from 3 605.8 kPa to 34.1 kPa. 3) The method for determining the water-induced linear expansion coefficient in layered roadbed construction resulted in greater water-induced expansion deformation compared to non-layered methods. This approach is considered more conservative and safer for engineering design. 4) The water-induced expansion of mudstone clasts exceeded the requirements specified in relevant standards, making them unsuitable for direct use as roadbed filler. However, adding 2% cement can effectively address this issue.