Review and investigation on stress sensitivity of naturally sedimentary soils

The mechanical behaviour of the naturally sedimentary soils generally differs from that of the reconstituted ones, due to the soil structure developed during the depositional and post-depositional processes. It has been well reported that the engineering disasters associated with oversize deformation and slope instability often occur due to damage or loss of the resistance originated from the soil structure. For quite some time, the mechanical behaviour of the reconstituted soils has been used as a reference for assessing the role of the soil structure in the mechanical behaviour of the naturally sedimentary soils. This study focuses on the stress sensitivity defined as the ratio of the consolidation yield stress of the naturally sedimentary soils to the equivalent one on the uniquely normalized compression line. The start-of-the-art methods for assessing the stress sensitivity are introduced. Based on the author's best knowledge, their advantages and disadvantages are analyzed. The development of the intrinsic compression framework is summarized by examining the related limitations. The unified normalised compression line propsoed by the author and her research team is recomended to investigate the changing law of the soil structure resistance during compression. The risk of the engineering disasters associated with its damage or loss is understood to call for high concern in engineering practice. Finally, the development trend of the approaches for assessing stress sensitivity is discussed. The compression zone of the naturally sedimentary soils without the soil structure resistance is suggested to be used as a reference for the development and improvement of the stress sensitivity framework in the future.