# Deformation Study of Strongly Structured Clays Considering Damage Effects
###### Abstract  
Settlement values calculated per the current \"Code for Design of Building Foundations\" demonstrate significant discrepancies when compared to the actual measured settlement values observed after disturbing a strong, cohesive soil foundation. This inconsistency introduces uncertainties in engineering design. To investigate the deformation behavior of highly structured clay, which is particularly sensitive to disturbances, this study employed a shaking table to subject undisturbed soil samples to various disturbance levels. The shaking frequencies were set at 20 Hz, 35 Hz, and 50 Hz, with durations of 30, 60, 90, and 120 min. One-dimensional compression tests were performed to examine the relationship between soil deformation parameters and overburden pressure, alongside an analysis of the deformation process and pore structure damage in the highly structured clay. A fitting process using Origin software was utilized to develop a deformation modulus calculation model that accounted for disturbance and damage effects, aiming to enhance the accuracy of foundation settlement predictions. The results indicate that the proposed empirical formula for the deformation modulus is highly reliable, which is essential for improving the precision of foundation settlement calculations and ensuring engineering safety.  
structural clay; degree of disturbance; degree of injury; characteristic of deformation +
Footnote †: journal: Applied sciences  
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curve of remolded soil at approximately the 0.42 e\({}_{0}\) point. Regarding the quantitative assessment of disturbance degree, scholars [PERSON] [18] and [PERSON] [19] proposed methods based on the slopes of compression curves before and after disturbance, along with pore water pressure measurements. [PERSON] et al. [20] evaluated disturbance degree by examining the ratio of effective stress in the soil prior to and following shield tunneling.  
Although these studies lay a foundation for understanding the deformation characteristics of structured clays, they largely overlook the interactions between overburden pressure, damage degree, and disturbance degree on soil deformation effects, particularly lacking quantitative analyses of soil damage degree. Therefore, it is crucial to incorporate damage degree and investigate the deformation behavior of highly structured clays sensitive to disturbance in engineering applications.  
This study examines the interactive effects of overburden pressure, damage degree, and disturbance degree on the deformation behavior of highly structured clay. Through one-dimensional compression tests, the behavior of this clay under various disturbance conditions was analyzed, with particular attention given to the impact of vibration duration and frequency on deformation characteristics. The findings reveal the evolving trends of pore structure damage as overburden pressure increases. The comprehensive effects of disturbance degree, damage degree, and overburden pressure on soil deformation characteristics are summarized, and an empirical formula for the deformation modulus that considers both soil damage and disturbance factors is proposed. This provides a theoretical foundation and reference model for the design and construction of foundations and subgrades that involve structured clay.