Dissipation Of Pore Water Pressure Research Articles

Consolidation and seepage solutions in enclosure space based on non-zero-constant values boundary.

Research is ongoing to find solutions to the problem of Consolidation and seepage in saturated clay in enclosure space. Firstly, the boundary of non-zero-constant values is established, considering the seepage boundary of the clay is affected by pumping water or lowering boundary pressure on the site. Secondly, the differential equation is established to reflect the spatial and temporal variations of excess pore water pressure dissipation in the clay in enclosure space, and the solution is derived using variable separation methods. Finally, based on results of the solution derived, contour maps of the water pressure are drawn corresponding with the different inhomogeneous boundary conditions.

Centrifuge modeling of levees with geocomposite chimney drain subjected to flooding

The objective of the present study is to evaluate the performance of a levee section when subjected to flooding and subsequent seepage through centrifuge model tests. For this, six centrifuge model tests were conducted on a 240 mm high levee model at 30g in a 4.5 m radius large beam geotechnical centrifuge available at the Indian Institute of Technology Bombay, India. A custom-developed flooding simulator is employed to induce identical flood rates on the upstream side of the levee models. Further, using (a) geocomposite (GC) and (b) sand-sandwiched geocomposite (SSGC) as internal chimney drain, the suitability of GC material for dissipation of pore-water pressure (PWP) is also studied. The results of the centrifuge tests are presented and discussed in terms of the development of upstream flood function, subsequent PWP development within the levee body, and the surface settlements observed at the levee's crest. Further, the influence of an internal chimney drain, the material used for its construction, and its type and composition on the seepage response of the levee is discussed in detail. The performance GC chimney drain placed within the levee section subjected to flooding-induced seepage is compared with a conventional sand chimney drain. It is observed that a GC-based chimney drain with sand cushioning on both sides in the horizontal portion of the chimney drain performs well. Further, digital image analysis of SEM micrographs of exhumed GC after centrifuge tests and the analyzed PWP data during sustained flooding-induced seepage is found to corroborate well.

Assessment of Axial Resistance of Piles Considering Consolidation Setup and Aging Setup Using Direct Pile Cone Penetration Test Methods

This paper focuses on evaluating the increase in axial pile resistance subjected to both consolidation and aging setups. Consolidation and aging setup models were first developed to estimate the setup parameters based on databases collected from literature, which include 10 instrumented piles for consolidation setup and 26 test piles for long-term aging. The eight top-performing pile cone penetration test (CPT) methods that were evaluated in a previous study were used to estimate the side resistance of soil layers at 14 days after pile driving. The developed consolidation and aging setup models were then used to extrapolate the results to evaluate the side resistance of each soil layer at the end of consolidation and for long-term aging. The estimated side and total resistances were compared with the measurements from pile load tests considering both consolidation and aging setups. The resistances estimated before and after completion of excess pore water pressure dissipation indicates that significant aging takes place after consolidation setup. The value of consolidation setup parameter ( Ac) was 0.53, and, for aging, the setup parameter ( Ag) was 0.23 in clay and 0.16 in sand. The results show that all pile CPT methods with/without using a consolidation setup model tend to underestimate the unit side resistance of clay soil layers. The use of pile CPT methods in combination with an aging model improved the accuracy of pile CPT methods, and this was verified using load test results for five piles subjected to aging. The Philipponnat and University of Florida (UF) methods showed the best performance on estimating the total resistance of piles subjected to aging.

Time-dependent performance of large piled raft in clayey soil

In this study, three-dimensional numerical analysis has been performed to comprehend the time-dependent behavior of large piled rafts founded in saturated clayey soil, explicitly for the time of superstructure construction and post-construction up to the end of soil consolidation. The performance under different construction times for the corresponding unpiled raft and the piled raft with uniform pile length configuration of varying pile number, spacing, and length have been examined and then compared with that of non-uniform length configuration for the same total pile length. The dissipation of excess pore water pressure, average settlement, and differential settlement are presented and discussed in detail. A quicker dissipation rate of excess pore pressure is noted with either fewer piles, wider pile spacing, or shorter-length piles. An increase in construction time results in a lesser total average settlement at the end of consolidation. The piled raft with uniform pile length configuration shows a higher differential settlement than the unpiled raft. However, by adopting a suitable non-uniform length configuration, negligible differential settlement, higher load-carrying capacity, and a significant reduction in pile material volume can be achieved. Predictive expressions have been proposed to estimate the average and differential settlements of piled raft with uniform length configuration.

Correction effect of jet-grouting on high-speed railway subgrade lateral deformation

Viable remediation of the large lateral deformation of high-speed railway (HSR) subgrades, especially in soft soil areas, is still absent. An integrated rectification scheme of high-pressure jet-grouting (HPJG) combined with stress-release techniques was conducted to rectify the large lateral deformation of an operational HSR subgrade in the soft soil area of China, but without any refined design and mechanical analysis before rectification due to the emergency. The objective of the study is to post-evaluate the rectification effects utilising field monitoring data and numerical calculations. The monitoring data showed that the maximum lateral deviation of the subgrade was 69.1 mm, which almost met the expected correction requirements. However, the influence of the excess pore water pressure (EPWP) dissipation on the correction deviation was not considered in the scheme. Therefore, a numerical model was established to further investigate this effect and corresponding mitigation methods. The calculated results revealed that EPWP in the foundation dissipated mostly within 6 months after rectification, and the deformation loss accounted for 30.7% of the total deviation. Prolonging the interval of two-row pile construction can be a plausible approach to mitigate the deviation loss. The findings provide a feasible method for correcting large lateral deformation of HSR subgrades.

Simplified analytical solution for time dependent deformation of soft soil improved with pervious column considering load transfer between column and soil

This paper presents a simplified analytical solution to analyse the coupled excess pore water pressure dissipation and deformation response of a composite stone column – soft soil foundation. The mathematical formulation is derived considering the combined radial – vertical flows of excess pore water pressure in stone column and soft soil areas (orthotropic permeability for each area), and adopting the settlement pattern for the composite ground suggested by an existing study in the literature. The homogeneous consolidation formulations are solved first to develop Green’s function for final excess pore water pressure solutions, employing the method of separation of variables and eigenfunction expansion technique. Then, the final solutions for excess pore water pressure corresponding to the nonhomogeneous consolidation formulations are derived in terms of Green’s formula, which can be expanded readily into a double series solution. The obtained analytical solutions can be used to examine the variation of excess pore water pressure against time at any point in the composite foundation. Thus, the consolidation settlements of stone column and soft soil areas and the differential settlement between them can be captured. The average differential settlement between the soil and column areas is used to compute the shear strains and shear stresses in the composite ground during the consolidation process. The proposed analytical solution is validated via a worked example in conjunction with a verification exercise against finite element simulation. The analytical predictions are presented in terms of the total vertical stress variations and excess pore water pressure dissipations against depth and time, the settlements and average degrees of consolidation for stone column and surrounding soft soil, and the shear stress distribution in the soil region. The capability of proposed analytical solution is also verified against field measurements of a full-scale test of soil - column composite ground (pervious column). The verifications show that the obtained analytical solution can predict the coupled excess pore water pressure dissipation – deformation response of soft soils improved by pervious columns such as stone columns and soil- deep cement mixing columns reasonably well.

The development of unit shaft resistance along driven piles in subsiding soil

The influence of bitumen coating on the development of unit shaft resistance along driven steel and precast concrete piles resulting from subsiding surrounding soft soil (gyttja) induced by fill placement at terrain was investigated. All piles were instrumented with conventional discrete-point vibrating wire strain gauges and distributed fibre optic sensors to achieve high-resolution strain measurements. The magnitude of the mobilised unit shaft resistance along uncoated piles was observed to be primarily related to an increase in effective stress resulting from the dissipation of excess pore water pressures. The unit shaft resistance along bitumen-coated piles was found to be primarily related to the rate of relative movement between pile and soil, which highlights the effectiveness of bitumen coating in reducing shaft resistance.

Analytical solution for consolidation of saturated viscoelastic soils around tunnels with general Voigt model

This paper presents a novel analytical solution for the consolidation behavior of viscoelastic saturated soft soil subjected to large-scale ground loading. The rheological properties of clay are described using the general Voigt model. Based on the Terzaghi-Rendulic theory, the governing equations for the dissipation of excess pore water pressure in the surrounding soil mass of a tunnel are established under the first and second boundary conditions. The governing equations are solved using the complex variable method. The obtained solutions are verified by reducing them to the forms of three traditional rheological models, demonstrating the reliability of the proposed approach. Finally, based on the established solutions, the dissipation characteristics of excess pore water pressure around the tunnel are analyzed. The case results indicate that the soil permeability coefficient (k), the independent Newtonian viscosity coefficient (K0) and Hooke’s spring modulus (E0) in the general Voigt model have significant influences on the dissipation of excess pore water pressure and the degree of consolidation. A larger k, K0, and E0 lead to faster dissipation and consolidation development, while a greater tunnel buried depth (b) results in slower consolidation process. The influence of k on excess pore water pressure dissipation is more significant than that of K0 and E0. For the first boundary type, consolidation is instantaneous when k > 0.1 m/d. For the second type, when k < 0.0001 m/d, excess pore pressure remains unchanged within 100 d. The permeability condition of the tunnel has a considerable impact on the distribution of excess pore water pressure in the soil layer directly above the crown. When the tunnel is fully permeable, the effects of k, K0, and E0 on the dissipation of excess pore water pressure are more pronounced in the early stage, with almost complete dissipation of excess pore pressure above the tunnel before 100 d. However, when the tunnel is completely impermeable, their effects are more prominent in the later stage, and by 100 d, the maximum excess pore pressure within the depth range is 25 % of the initial.

Evaluating hydraulic parameters in clays based on in situ tests

Abstract The permeability of soil is an important factor controlling the flow of water through the subsoil. The article presents the results of studies of hydraulic parameters for overconsolidated clays using in situ tests. Using the excess pore pressure normalization technique, both in the case of monotonic and dilatory dissipation tests, and the time at which 50% dissipation of excess pore water pressure takes place, as well as taking into account the rigidity index of the analyzed soil, it was possible to estimate the permeability and consolidation coefficients for the analyzed clays. Based on these studies, simple relationships between the permeability coefficient and the soil behavior-type index are proposed. Proposed formulas may be applied for overconsolidated cohesive soils with soil behavior-type index values within the range of 2.05–3.30 and described in Robertson’s chart as overconsolidated silty clays, clays and heavily overconsolidated and cemented fine-grained soils. Although our proposal of determining flow parameters has been calibrated only for two analyzed cases, its utility for wider use in other overconsolidated fine-grained soils may also be taken into account.

Semi-numerical analysis of negative skin friction on permeable pile due to consolidation induced by piling

A semi-numerical approach is proposed to estimate the dissipation of excess pore water pressure and the development of negative skin friction at the normal impervious pile and the permeable pile after piling. An impeded drainage boundary associated with the opening ratio and opening size is introduced to simulate the drainage condition at the soil-permeable pile interface. In the proposed mathematical framework, analytical approaches are adopted to solve the linear equations, and numerical techniques are utilized to address the nonlinear problems so that the adaptivity and efficiency of the mathematical framework can be well balanced. Through comparisons with the field tests, the model tests, and the theoretical answers, the correctness and rationality of the proposed method are validated. Through a parametric study, the key design parameters of the permeable pile are investigated, and the following design tips are obtained: 1. The opening ratio plays the most important role in the drainage efficiency of the permeable pile; 2. Increasing the number of openings is preferred rather than increasing the size of openings, especially when the opening ratio is determined.

Finite-difference solution for dissipation of excess pore water pressure within liquefied soil stabilized by stone columns with consideration of coupled radial-vertical seepage

The implementation of stone columns is a widely accepted method for improving the stability of liquefiable soil. A comprehensive understanding of the behavior of the composite ground is crucial for accurate design and calculation in practical applications. Several existing mathematical models were established to assess characteristics of the stone column-improved ground by typically ignoring the vertical seepage within liquefiable soil. This negligence will inevitably lead to significant calculation errors, particularly when the vertical permeability of liquefiable sites is high or the installation spacing of stone columns is large. In this context, a new mathematical model which accounts for coupled radial-vertical seepage within liquefiable soil is proposed to determine the reinforcement performance of stone columns. The equal strain assumption and new boundary conditions are incorporated to obtain numerical solutions with the finite difference method. Then the present solution is degenerated to the conventional calculation model to verify the reasonability of the proposed model. Finally, a parametric analysis is conducted to investigate the impacts of crucial parameters on the performance of stone columns for excess pore water pressure variation during soil liquefaction. The results reveal that the peak value of the maximum excess pore water pressure ratio increases with the increment of both the column spacing and cyclic stress ratio. Moreover, the increasing radial and vertical consolidation parameters Tb and Th will accelerate the dissipation rate of the excess pore water pressure of liquefiable sites. Furthermore, the conventional model neglecting the vertical seepage will underestimate the variation rate of the excess pore water pressure, and the calculation error will become larger with the increase of Th.

Prediction Analysis on Coefficient of Consolidation Values in Improved Soft Clays

Consolidation is a phenomenon in soil mechanics that often causes geotechnical problems. One solution to overcome consolidation phenomena is by speeding up process of pore water pressure dissipation. The type of soil improvement to upgrade the performance of soft clay is by applying pre-fabricated vertical drain (PVD) and pre-compression simultaneously. Geotechnical instrumentations such as settlement plates, piezometers, and inclinometers were installed at the field of study to monitor magnitude of settlement during consolidation process. After the final settlement was achieved, the consolidation parameters such as coefficient of consolidation, and rate of settlement, were back calculated. Prediction analysis of consolidations parameters was performed by means of Asaoka method. The results of this study is very interesting and provide useful engineering information. It is interesting to note that this case study may be beneficial use to practicing engineers and researchers.

Integration of Sentinel–1 and Landsat–8 data for identifying deformation risk of hydraulic engineering in seasonally frozen salinization regions

Hydraulic engineering has positive effects on agricultural production and soil desalination. However, freeze–thaw cycles can cause instability in canal slopes, emphasizing the need for effective deformation monitoring. Using Sentinel-1B data acquired from November 2017 to August 2019 and applying the small baseline subset (SBAS) InSAR method, two unstable canal segments with vertical deformation rates exceeding –40 mm/year were identified in Songyuan, Northeast China. The canal slopes uplifted in winter and experienced accelerated subsidence in spring, with the shady slope experiencing a deformation rate approximately 10 mm/year faster than the sunny slope. Further investigation, integrating Landsat–8 data collected from November 2017 to August 2019, revealed that the shady slope received less thermal radiation than the sunny slope, with an average annual temperature difference on the land surface of approximately 1 ℃. In winter, the saline–alkali soil particles formed a thick unfrozen water film, which, driven by temperature and soil–water gradients, migrated towards the freezing front, froze, and caused soil frost heave. The shady slope experienced longer freezing periods and deeper frozen depths, up to 240 cm, causing more unfrozen water migration and greater uplift deformation than the sunny slope. In spring, as temperature rose, the soil thawed from the surface downward. Notably, the shady slope thawed at a slower rate than the sunny slope, forming a frozen lens near a depth of 100 cm. Frozen lens acted as a barrier for meltwater infiltration, impeding the dissipation of pore water pressure, making the shady slope prone to surface landslides. The integration of multiple data sources is beneficial for identifying deformation risk in hydraulic engineering.

A semi-analytical solution for consolidation of soft ground improved by locally permeable pipe piles under time-dependent loads

Excessive pore-water pressure in soft soil can compromise pile bearing capacity, leading to foundation failure and posing a risk to structure stability. Hence expedited dissipation of excess pore-water pressure is critical. Permeable pipe piles offer an alternative to accelerating this consolidation process. In this study, a modified vertical equal-strain consolidation model of composite foundations with locally permeable pipe piles under arbitrary time-dependent loads is investigated. The integral transform and boundary transform methods are used to obtain a semi-analytical solution to this consolidation problem. The proposed solution’s validity and correctness are further confirmed via theoretical degradation and numerical analysis. Subsequently, a sensitivity analysis in terms of opening parameters, pile-soil modulus ratio, soil’s hydraulic conductivity ratio and pile’s length-diameter ratio is conducted. The results indicate that the consolidation rate of the permeable pipe pile composite foundations demonstrates a significant enhancement over impermeable pipe pile composite foundations, especially for deep and soft foundations with high hydraulic conductivity ratios. The consolidation efficiency improves with the increase of pile’s opening ratio, opening length and opening depth until it reaches a plateau at larger opening parameters. The research can provide theoretical support for design and construction of infrastructure with permeable pipe pile composite foundations.

Investigating Deformation Mechanism of Earth-Rock Dams with InSaR and Numerical Simulation: Application to Liuduzhai Reservoir Dam, China

Ground deformation is the direct manifestation of the earth-rock dam's hazard potential. Therefore, it is essential to monitor deformation for dam warning and security evaluation. The Liuduzhai Dam, a clay-core dam of a large reservoir in China, was reinforced with plastic concrete cut-off walls between 13 January 2009 and 29 May 2010, as it was subject to leakage and deformation. However, the deformation development and the mechanism of the dam are still unclear. In this study, the deformation fields before and after the reinforcement of the Liuduzhai Dam were yielded by using the Interferometric Synthetic Aperture Radar (InSAR) technique. Furthermore, a numerical simulation method was employed to obtain the dynamic seepage field of the dam during the InSAR observation period. The results indicated that the average deformation velocity and maximum deformation velocity are −11.7 mm/yr and −22.5 mm/yr, respectively, and the cumulative displacement exceeds 100 mm, which shows typical continuous growth characteristics in a time series. In contrast, the dam deformation tended to be stable after reinforcement, with the average deformation velocity and maximum deformation velocity being −0.4 mm/yr and −1.2 mm/yr, respectively, behaving as cyclical deformation time series. According to the results of InSAR and seepage analysis, it is shown that: (1) dynamic seepage was the main mechanism controlling dam deformation prior to reinforcement; (2) the concentrated load caused by construction and the rapid dissipation of pore water pressure caused by the sudden drop of the infiltration line were the reasons for the acceleration of deformation during and after construction; and (3) the plastic concrete cut-off walls effectively reduced the dynamic seepage field, while the water level fluctuations were the main driving factor of elastic deformation of the dam after reinforcement. This study provides a novel approach to investigating the deformation mechanism of earth-rock dams. Furthermore, it has been confirmed that InSAR can identify the seepage deformation of dams by detecting surface movements. It is recommended that InSAR deformation monitoring should be incorporated into future dam safety programs to provide detailed deformation signals. By analyzing the temporal and spatial characteristics of the deformation signal, we can identify areas where dam performance has degraded. This crucial information aids in conducting a comprehensive dam safety assessment.

Seismic site response analysis of liquefiable soil deposits focusing on the ground surface response spectrum

A numerical algorithm is developed for conducting one-dimensional non-linear ground response analysis of layered sites, capable of reproducing liquefaction phenomena and accounting for the simultaneous dissipation of excess pore water pressure through soil grains. Τhe shear wave propagation algorithm is based on the plasticity constitutive model for sand Ta-Ger, expressed in a one dimensional p-q space form. This model demonstrates remarkable versatility in representing complex patterns of the cyclic behavior of sand, such as stiffness decay and strength reduction due to pore-water pressure buildup. The calibration of the model is based on shear modulus reduction and damping curves for drained loading conditions, as well as liquefaction resistance curves for undrained conditions. A detailed presentation of the numerical model formulation is provided, outlining the numerical approach for solving the wave propagation and consolidation differential equations. To validate model predictions, the recorded seismic ground response of the Port Island array during the 1995 Kobe earthquake is utilized. Furthermore, the model is applied to estimate the elastic response spectra at the surface of soil profiles with liquefiable layers (ground type S2) as per EC8:2004. The investigation involves the ground response analysis of various soil p3rofiles, all including a liquefiable zone, excited by a suite of earthquake motions at their base. The acceleration time histories are extracted from the PEER Ground Motion Database, having characteristics compatible with the NGA-estimated response spectrum at the bedrock as well as key seismological parameters such as the earthquake magnitude Mw and the horizontal distance from the fault RJB. Two different methods are employed for selecting the base excitations: amplitude-scaled records to match a target response spectrum and spectral-matched records. From the results, an idealized response spectrum is derived in terms of the design spectrum parameters S, η, ΤΒ and TC. The findings demonstrate that the idealized ground surface response spectrum is minimally sensitive to the method used for base excitation selection.

Monotonic and Cyclic Simple Shear Response of Well-Graded Sandy Gravel Soils from Wellington, New Zealand

In the 2016 Kaikoura earthquake, liquefaction of gravelly soils from reclaimed fills occurred in CentrePort, Wellington, New Zealand. This study presents constant volume monotonic and cyclic simple shear tests on well-graded gravel with sand collected from CentrePort. A large-scale cyclic simple shear device is utilized to evaluate the monotonic, cyclic, and postcyclic responses of the sandy gravel soils. Specimens prepared at various relative densities were subjected to a vertical effective stress of 100 kPa and then monotonically and cyclically sheared. After the cyclic loading, the postcyclic response was evaluated, including volumetric compression or monotonic shear with or without dissipation of excess pore water pressure. Shear wave velocity was measured before and after the cyclic loading. The results show that the well-graded sandy gravel has a high potential for liquefaction, with higher relative density specimens having higher liquefaction resistance. Postcyclic volumetric strain is primarily correlated with density and maximum shear strain during cyclic loading. Postcyclic reconsolidation causes densification of the liquefied specimens, resulting in higher monotonic shear resistance, while postcyclic monotonic shear without dissipation of excess pore water pressure reveals that substantial shear strain is required to develop the shear resistance. Shear wave velocity was significantly reduced after liquefaction, but recovered to slightly higher than its precyclic shear values after reconsolidation. Compared to other gravelly and sandy soils, the well-graded sandy gravel showed a similar or slightly higher liquefaction resistance than gap-graded and uniform gravels. Moreover, the well-graded sandy gravel had a relatively lower ultimate postcyclic volumetric strain due to a small variation between its maximum and minimum void ratios. The results advance our understanding of the liquefaction resistance and subsequent postcyclic responses of the well-graded sandy gravel soils.

Modelling biogeochemical clogging affecting piezometers in acid sulfate soil terrain

This study offers an analytical solution for radial consolidation that captures the biogeochemical clogging effect in acid sulfate soils. Field sites and personal communication with industry practitioners have provided evidence of piezometers exhibiting retarded pore pressure readings that do not follow conventional soil consolidation and seepage principles when installed in coastal acidic floodplains. This retarded response together with a variation in pH, ion concentrations, and piezometric heads provided evidence of clogging at and around the piezometers. This paper uses the proposed biogeochemical clogging model, which is an analytically derived system of equations to estimate the excess pore water pressure dissipation of piezometers installed in clogging-prone acid sulfate soils. The inclusion of the total porosity reduction attributed to biological and geochemical clogging improves the predictions of the retarded dissipation of excess pore pressure, especially after about 1 year. This method is validated for two previously identified acidic field sites in coastal Australia, where piezometers measured a very slow rate of dissipation. It is concluded that this model has potential to accurately monitor the performance of critical infrastructure, such as dams and embankment foundations built on acidic terrain.

EFFECT OF CHANGE IN THE COEFFICIENT OF PERMEABILITY ON CONSOLIDATION CHARACTERISTICS OF CLAYS

The settlement rate and pore water pressure dissipation rate are mainly controlled by the permeability of soil. Both laboratory and field tests show that the permeability is varied during the loading and consolidation process. It is known that consolidation process is accompanied by decrease in void ratio which leads to decrease in the coefficient of permeability. The importance of the decrease of the coefficient of permeability on the time rate of settlement and pore water pressure needs to be investigated.This paper takes into account the change in coefficient of permeability during consolidation and studies its effect on consolidation characteristics of a clay layer. The finite element method is used in the analysis and the package Geo-Slope is adopted through coupling the programs SIGMA/W and SEEP/W. The relationship between the applied pressure and permeability was determined experimentally for three samples.It was concluded that the effect of permeability is clear at later times of consolidation due to decrease in void ratio and hence slower dissipation of pore water pressure. Taking into account variable permeability leads to longer times of consolidation. At later times (after 400 days), the excess pore water pressure predicted for the case of variable permeability is greater thanconventional case by about (10 – 12) %.

Influence of water content on clay deformation characteristics subjected to periodic intermittent loading

The influence of clay's drainage and reconsolidation behavior during the intermittent period on clay's deformation needs to be further studied. Dynamic loads, such as traffic and earthquake, etc., have a certain intermittent period during the loading process. This study examined the deformation behavior of the clay obtained from Nanchang under various cyclic stress ratios (CSR) and water content conditions. The results demonstrated that minor strain rebound occurs in all intermittent periods. Aside from that, drainage reconsolidation during intermittent periods alters the pattern of strain accumulation during subsequent loading periods, and cyclic stress levels and water content conditions can impact the intermittent effects. In contrast, the development of strain in the samples under intermittent loading is more negatively impacted by high CSR and low water content (deviation from optimal water content). The hysteresis curve continued to change throughout the test, the accumulation and dissipation of excess pore water pressure changed, and it was found that the samples' resilient modulus had increased, indicating an improvement in the samples' resistance to deformation.