Coefficient Of Volume Change Research Articles

Evaluation of citric acid-treated natural fibres as sustainable additives for improving expansive soil performance in highway construction

This study addresses the evaluation of citric acid-treated natural fibres as sustainable additives for improving soil performance in highway construction. A series of tests were conducted on the soil to assess its baseline properties. The natural soil exhibited a Plasticity Index (PI) of 30 and Linear Shrinkage of 12%, along with a Liquid Limit (LL) of 65 and Plastic Limit (PL) of 35. Additionally, the fines content (<0.075 mm) and sand content (0.075–4.7 mm) were determined to be 79.6% and 20.4%, respectively. The soil's mineral composition included Quartz (5%), Orthoclase (3–5%), Montmorillonite (2.6%), and Illite (18.2%), with key components identified through chemical analysis: SiO2 (52.721 wt%), Fe2O3 (16.132 wt%), and Al2O3 (15.202 wt%). Subsequently, a range of tests were performed with varying additives to assess their impact on the soil's engineering properties. The sample containing 6% Sawdust (SD) additive exhibited notable improvements in multiple aspects. This sample achieved a maximum dry density (MDD) of 1856 kg/m³, surpassing the control (1900 kg/m³) and the 10% Rice Husk Ash (RHF) sample (1698 kg/m³). Furthermore, the 6% SD sample demonstrated enhanced Unconfined Compressive Strength (UCS) of 320 kPa, as opposed to the control's 121 kPa. Triaxial shear strength followed a similar pattern, peaking at 41 kPa for the 6% SD sample. The California Bearing Ratio (CBR), the 6% SD sample showcased significant improvements, achieving 41% for Unsoaked CBR and 36% for Soaked CBR. These results outperformed the control (25%) and the 4% RHF sample (37%). Additionally, the hydraulic conductivity of the 6% SD sample was notably lower at 4.98 ×10–8 cm/s compared to the control (3.35 ×10–8 cm/s) and the 4% RHF sample (4.58 ×10–8 cm/s). The Coefficient of Volume Change (Mv) further supported the superior performance of the 6% SD sample with a value of 0.6, indicating reduced settlement potential compared to the 4% RHF sample (Mv: 0.7). Based on the results, the 6% Sawdust (SD) additive consistently demonstrated the most favourable engineering properties for the expansive clay soil. hence, it is recommended that the 6% SD sample be considered as an optimal choice for enhancing subgrade material, leading to improved performance and sustainability in highway construction.

Correlation between one-dimensional consolidation coefficients and different basalt fiber lengths and RHA-cement contents in fiber-reinforced stabilized expansive soils

Recently, environmentally friendly soil reinforcement and stabilization techniques, used to reconstitute weak expansive soils, are on the rise, calling for an in-depth analysis of the consolidation projections on the engineering structures built on them. This study investigated one-dimensional consolidation coefficients by conducting a series of oedometer tests on expansive soils reinforced with basalt fibers of different lengths, stabilized with rice husk ash (RHA) as an environmentally friendly cement-reducing aggregate, and nominal dosages of cement in specified combinations. The correlation between the coefficients of consolidation (cv), volume change (mv), and permeability (k) and different basalt fiber lengths and RHA-cement contents in ultimate soil composite material was quantified using equations and graphical forms. Furthermore, scanning electron microscopic imagery (SEM) was conducted to examine the structural modifications within the reinforced and stabilized soil specimens upon one-dimensional consolidation. The results showed that basalt fiber-reinforced specimens, comprised of 5% RHA and 3% cement mixtures, showed the lowest one-dimensional consolidation coefficients with a notably greater reduction at high-stress states than the control specimen. Additionally, the coefficients of volume change (mv) and permeability (k) decreased with the increased compactive effort, with a clear and significant reduction in the basalt fiber-reinforced stabilized soil composites. This study also proposed the best material combination scheme and analytical equations for evaluating the cv, mv, and k considering basalt fiber lengths at different pressure levels. The ultimate soil composites had superior properties, and thus, can be used as fill or subbase material for such engineering structures as embankments, pavements, and foundations.

Perencanaan Pondasi Borepile Pada Jembatan, Studi Kasus : Jembatan Utama Cisadane

The most important part in a bridge construction is the foundation. Bore pile foundation is planned for 2 abutments and 5 piers. The entire foundation uses a diameter of 1 meter with a depth of 20-30 meters. Calculation of axial bearing capacity using the reese and wright method produces a single pile axial bearing capacity of 268.090 - 470.697 tons. The efficiency of the pile group using the Converse-Labarre method and the axial bearing capacity of the pile group is 5870,246 - 33176,233 tons. Single pile settlement using a semi-empirical method and resulted in a decrease of 50,100 - 59,490 mm. The settlement of the pile group used the vesic method and resulted in a decrease of 6,627 - 13,302 cm. consolidation decrease using the coefficient of volume change and resulted in a decrease of 104,024-576.047 mm with a time of 5,694-26,731 years. The calculation of lateral bearing capacity and pile deflection using the Broms method resulted in the lateral bearing capacity of the pile group of 3024-20580 tons and deflection of 1.485-5.888 mm. foundation reinforcement using the reference of SNI 2847-2019. Longitudinal reinforcement using 10D32 and stirrup reinforcement D16-50 and D16-75. Pile cap planning refers to SNI 2847-2019, resulting in a pile cap thickness of 1.5-4 meters. The X direction and Y direction reinforcement used are D32-150 for the pier and D32-150 and D25-150 for the abutment. The calculation of the cost budget plan uses the unit price analysis method and the resulting total cost is 73.574.031.053.

A universal model for describing responsive performances of both positively and negatively responsive smart gating membranes

In this study, a universal model is developed for describing the responsive performances of both positively and negatively responsive smart gating membranes with structural and responsive parameters. The model is derived by assigning the membrane pore size change ratio before and after immobilizing responsive gates and the volume change coefficient as well as the stacking effect coefficient of responsive gates as independent dimensionless variables. The reliability and fitting precision of the proposed model have been validated by the experimental results of positively thermo-responsive and negatively Pb2+-responsive gating performances of smart gating membranes, which are prepared by immobilizing poly(N-isopropylmethacrylamide-co-4-acrylamidobenzo-18-crown-6) (PNMB) microgels in porous poly(ether sulfone) (PES) membranes as functional gates that exhibit both thermo-induced shrinking and Pb2+-induced swelling responsive characteristics. All the experimental data of both positively and negatively responsive gating performances of smart gating membranes fit well with the developed model. The proposed model provides new insights for describing and explaining the responsive gating performances of both positively and negatively responsive smart gating membranes, and offers rational guidelines for designing and fabricating smart gating membranes with desired responsive gating performances by predetermining the structural and responsive parameters of smart gates for various applications.

Consolidation Properties of Soil/Modified Bentonite Backfill in Salt Solution

The consolidation properties of soil-bentonite (SB) backfills containing 20% of the weight of sodium-hexametaphosphate-modified calcium bentonite (SHMP-20CaB) and prepared with 0 mM to 1000 mM calcium chloride (CaCl2) solution were evaluated. The results indicated that both consolidation stress and CaCl2 concentration had significant effects on the consolidation behaviors of the SHMP-20CaB backfill. In general, an increase in consolidation stress resulted in a decrease in the void ratio (e) and in the coefficient of volume change (mv), alongside an increase in the coefficient of consolidation (cv). The increased CaCl2 concentration yielded a dropped void ratio, and a nonlinear decreased compression index (Cc) and rebound index (Cs), respectively, from 0.18 to 0.13 and from 0.022 to 0.010, and a nonlinear increase cv. A threshold CaCl2 concentration of 100 mM was observed at the inflection points of the Cc, Cs, and cv. In contrast, the mv was insensitive to the CaCl2 solutions. The deterioration in e, Cc, and Cs and the increase in cv were the result of a compressed diffuse double layer of the bentonite by the CaCl2 solution, which thus exerted certain negative effects on the consolidation behaviors of the SHMP-20CaB backfill.

Effect of Stone Columns on Strength and Consolidation Characteristics of Black Cotton Soil

One fifth of the land mass in India is covered by black cotton soil (BCS). Due to low permeability, poor strength and high compressibility, they pose huge engineering problems. In the present study, the influence of stone column on the consolidation and strength behaviour of black cotton soil is meticulously studied. Laboratory tests are carried out on both end bearing and floating type stone columns, having diameters (d) 50 mm, 60 mm and 70 mm with l/d ratios 3, 4 and 5 (l being the length of stone column), installed in black cotton soil. The load-settlement and consolidation behaviour of unreinforced and reinforced black cotton soil are compared. It has been found that for d = 60 mm and l/d = 3, the load carrying capacity for reinforced BCS increases by 23% and 20% for end bearing and floating type stone columns, respectively. Moreover the void ratio (e), coefficient of compressibility (av), coefficient of volume change (mv), coefficient of consolidation (Cv), coefficient of permeability (k) and compression index (Cc) of black cotton soils are significantly affected by the l/d ratio and diameter of the stone column. The present study reflects the efficiency of stone columns as suitable ground improvement technique for BCS.

The effect of temperature on some engineering and consolidation properties of soft soil

This article defines the effect of temperature on some engineering and consolidation properties of soft soil. The purpose of this research, therefore, was to determine the technical characteristics of soft clay consolidation behavior, specifically in terms of temperature influence on varying values of soil established mechanical parameters, including soft soil compression index (Cc), swelling index (Cs), volume change coefficient (mv), consolidation coefficient (Cv), and the permeability coefficient (k). In this analysis, the use of soft clay in an undisturbed condition was sourced from a swampy location in South Kalimantan Province, Indonesia. Also, the temperatures applied to the specimens were 22o C, 40o C, 60o C, and 70o C. The results showed the influence of temperature modifications on soil compressibility, where extensive heat was responsible for abundant soil compressibility. In addition, the associated parameters, termed soil compression index value (Cc), consolidation coefficient (Cv), and the swelling index (Cs), observed an increase by 3%, 33%, and 22%, respectively. Furthermore, existence of high temperatures limited the unstable soil volume, where the volume change coefficient (mV) tends to decrease by 3%. Also, varying temperatures essentially altered soil permeability, where the seepage properties of soft clay showed the tendency to increase by 32%, with rising soil temperature.

Effect of rubber tire on behaviour of subgrade expansive Iraqi soils

In this study focuses on improving an expansive soils geotechnical properties treated by tire crumble and decreasing the natural contamination by this waste material. The waste rubber of tire in the form of crumble with size ranging between 0.08 to 2 mm with proportion from 0 to 10% was used in this examination. Routine tests such as compaction, unconfined compressive strength, consolidation and swelling pressure test have been done on untreated and treated soils with crumble tire rubber. According to the test results it was found that, the maximum dry density of treated samples decrease with increased tire crumble content, while a slight reduction in the optimum moisture content was found simultaneously. Also, the results of unconfined compression tests showed that, the crumble tire rubber could not improve the properties despite the fact that that the soil still in the hardened consistency. In like manner results demonstrate that using crumble rubber might be successful procedure in upgrading the soil characteristics against swelling potential of soils by approximately 29.8, 43.4, 49.39, 14.77 times than untreated soil for (1, 3, 5, 10%) tire crumble rubber content. In addition the results show increasing crumble tire rubber content from 1 to 5% gave low displacement values by about (26.01 - 43.9)% than its value in untreated samples. Finally, it has additionally seen that using of crumble tire rubber aides in decreasing the compression index, consolidation coefficient, permeability coefficient and volume change coefficient.

Consolidation Characteristics of Artificially Structured Kaolin‐Bentonite Mixtures with Different Pore Fluids

The consolidation characteristics of kaolin, bentonite, their mixtures, and natural clays have been widely evaluated. However, the effect of pore fluid on the consolidation characteristics of artificially structured kaolin‐bentonite mixtures should be more investigated. In this study, the oedometer tests were carried out on mixtures of kaolin with 10%, 20%, and 30% bentonite reconstituted with distilled water and 1 M NaCl. The testing samples with an “artificial structure” were prepared using the preconsolidation procedure. The test results show that bentonite greatly affects the consolidation behavior of mixture samples, especially when the pore fluid is distilled water. In the case of distilled water, the addition of bentonite to kaolin clay significantly increased the compression index (Cc), swelling index (Cs), and coefficient of volume change (mv). In this case, the mv of mixture samples increased significantly at low effective axial stress (σ′a) levels (less than the preconsolidation pressure) and then decreased as the σ′a further increased. In the case of 1 M NaCl as the pore fluid, the Cc, Cs, and mv slightly changed with the increase of bentonite content. The research results also confirmed that the effect of saline water on the compression index was noticeable when the liquid limit of soil with distilled water was higher than 110%, and the compression index of soil with distilled water was higher than 1. Regarding the coefficient of consolidation (Cv), the Cv of kaolin sample increased as the σ′a increased, and this trend was independent of the pore fluid chemistry. By contrast, the Cv − σ′a trend of mixture samples depended not only on the pore fluids but also on the stress level.

An Investigation into the Compressibility and Lateral Stresses of Sand–Carpet Mixtures Using a Large Oedometer Apparatus

In this paper, the deformation properties of sand, reinforced with carpet waste, are investigated by carrying out a set of large-scale oedometer tests under different overburden pressures. The oedometer apparatus employed in this study has been equipped with vertical and lateral pressure cells, which allow the value of the soil’s coefficient of lateral pressure at rest, to be determined as well as its compressibility. Carpet waste was added to sand at weight percentages of 0, 5, 10 and 15%. Results were indicative of a reduction in the coefficient of lateral pressure at rest, K0 with the increase in carpet content of the mixtures. The reduction in the value of K0 amounted to 10% at a carpet content of 15%. The compressibility properties of the mixtures were evaluated as well, by recording one-dimensional displacement in the samples. Results demonstrated an increase in the coefficient of volume change with the increase in carpet content, particularly for lower levels of overburden pressure. Predictive models were developed based on the multi-linear regression (MLR) procedure to predict the coefficient of lateral pressure at rest and coefficient of volume change for the sand–carpet mixtures normalized to the values of sand.

Coefficient of Consolidation and Volume Change for 3-D Consolidation

The settlement is the most serious problem of fine soil. This settlement is caused by a phenomenon called soil consolidation. Most previous studies were concerned with studying one (1-D) and two-dimensional (2-D) consolidation. That in some cases does not give a simulation of reality representation. It was necessary to study the three-dimensional (3-D) consolidation to simulate what happens to the fine soil in nature. Therefore, the consolidation behavior of four fine soils was studied in this paper. The studied soil samples were collected at the foundation levels of four different sites in El-Qalubia governorate, Egypt. A series of laboratory consolidation tests were carried out as one, two and three dimensional consolidation by using manufactured Oedometer apparatus. So, the effect of consolidation conditions (1-D, 2-D and 3-D) on consolidation coefficient (Cv) and volume change coefficient (mv) was investigated. Also, an empirical equation was correlated the relationship between Cv and mv.

Coefficient of Consolidation and Volume Change for 3-D Consolidation

The settlement is the most serious problem of fine soil. This settlement is caused by a phenomenon called soil consolidation. Most previous studies were concerned with studying one (1-D) and two-dimensional (2-D) consolidation. That in some cases does not give a simulation of reality representation. It was necessary to study the three-dimensional (3-D) consolidation to simulate what happens to the fine soil in nature. Therefore, the consolidation behavior of four fine soils was studied in this paper. The studied soil samples were collected at the foundation levels of four different sites in El-Qalubia governorate, Egypt. A series of laboratory consolidation tests were carried out as one, two and three dimensional consolidation by using manufactured Oedometer apparatus. So, the effect of consolidation conditions (1-D, 2-D and 3-D) on consolidation coefficient (Cv) and volume change coefficient (mv) was investigated. Also, an empirical equation was correlated the relationship between Cv and mv.

Influence of various concentration of lead on consolidation parameters of bentonite

ABSTRACT Influence of concentrations of lead (Pb2+) on consolidation behaviour of bentonite was investigated. Various parameters such as coefficient of consolidation (cv ), coefficient of volume change (mv ), time for 90% of consolidation (t90) and compression index (Cc ) and Swelling potential and swelling pressure in the presence of the various lead concentration ranging from 250 to 1000 mg/L. The results manifested that with the increase in lead concentration, the swelling pressure, swelling potential and cv increased; however, Cc, mv and t90 of the bentonite decreased. A decrease in diffuse double layer (DDL) thickness as the Pb2+ gets adsorbed by bentonite is responsible for the change in these parameters. The results show that the impact of Pb2+ on bentonite was more dominant at higher concentration. Results also revealed that with the rise in vertical consolidation pressure, t90 increased, whereas cv decreased. However, mv increased initially and then decreased after reaching a peak value.

English

The geotechnical properties of Daki Biyu district in the Federal Capital Territory, Abuja, Nigeria was investigated to ascertain the suitability of the sub-surface soil to support massive infrastructure such as high rise building and industries that might be carried out in the future. The particle size distribution shows that the soil is predominantly sandy-clay to sandy-gravels. The plasticity indices suggest low to medium compressibility while the co-efficient of volume change (Mv) and the coefficient of consolidation (Cv) are generally low for most of the pressure ranges. The average allowable bearing capacity values of 150 kN/m2 -240 kN/m2 and an average of 460 kN/m2 -700 kN/m2 for the ultimate bearing capacity agrees with the national building code (1983) for safe bearing capacity for cohesionless soils. The sub-surface soils were found to possess good geotechnical properties that are capable of supporting infrastructural development. Key words: Geotechnical investigation, bearing capacity, compressibility, consolidation, borehole log.

Constant rate of strain consolidation of organic clay: in Kolkata region

Constant rate of strain (CRS) consolidation test is an alternative testing method to estimate the consolidation parameters of fine grained soils, which has gained popularity in countries, such as USA, Japan, Hong Kong, and Canada, because of its several merits over conventional incremental loading (IL) method. Constant rate of strain test is also important to study the effect of strain rate on consolidation behavior of soils. Organic soils are considered problematic soils because of their low strength and higher compressibility. In this paper, an attempt has been made to determine consolidation parameters of a number of undisturbed and remolded organic soils in the Kolkata region with organic content 14–45% by testing them at different strain rates (1·2, 0·24, 0·12, 0·048, and 0·012% min−1) using an indigenously built CRS cell. Incremental loading tests were also conducted to verify the dependability of CRS results. Results indicate that 1·2 and 0·24% min−1 strain rates generate high pore pressure ratio (PPR), which are beyond the recommended values. Present investigation revealed that vertical effective stresses, pre-consolidation pressure, coefficient of consolidation, coefficient of volume change, hydraulic conductivity, etc., are strain-rate dependent. Higher strain rate is found to produce higher effective stress and consolidation parameters. Constant rate of strain test results obtained from undisturbed organic clays (OCs) and a number of remolded organic and inorganic soils particularly at 0·12, 0·048, and 0·012% min−1 strain rates are in line with that of IL tests.

Effect of Clay Mineralogy on Coefficient of Consolidation

The coefficient of consolidation (Cv) signifies the rate at which a saturated clay undergoes 1-dimensional consolidation when subjected to an increase in pres- sure. Measured in cm2/s, C~ is a function of hydraulic conductivity, k (crn/s), coefficient of volume change, mv (cm2/kg), and unit weight of pore fluid, ~w (kg/cm3), and is expressed as:

The Determination of Glacial Till Specific Storage in North Dakota

AbstractSpecific storage (Ss) was calculated for 107 glacial till core samples collected in 1962 from 93 drilling sites at U.S. Air Force Intercontinental Ballistic Missile launch and launch control facilities located in North Dakota. Core sample depths ranged from 8 to 26 m. Consolidation tests were performed on the till samples using a floating ring consolidometer. The coefficient of volume change (mv), which is defined as the volume change per unit volume per unit increase in effective stress, was calculated for this study using previously reported consolidation test data. Ss calculated for the 107 till samples ranged from 2.0 × 10‐4m‐1 to 1.1 × 10‐3m‐1, with a mean value of 5.6 × 0‐4m‐1.Till is easily compressible and, as a result, Ss is not constant, but rather a function of loading. With increased depth, effective stress (σ0) increases and Ss decreases. Based on data from 107 till cores in this study, the relationship between σ0 and Ss is described by: Ss= 0.049σ0−0.84, (r2= 0.60, p&lt;0.0001), where σ0= in situ effective stress in kPa, and Ss= specific storage in m‐1.

Volume change indices during loading and unloading of an unsaturated soil

The paper presents the volume change theory and the designation of associated soil properties that must be measured for an unsaturated soil. The equipment required for the measurement of each of the relevant volume relationships is described. Several testing procedures for obtaining the volume change indices during loading and unloading of an unsaturated soil are presented. Typical results from loading and unloading tests on compacted silt and compacted glacial till specimens are presented and analyzed. The analysis is given in order to illustrate the application of the volume change theory to practical problems. Key words : unsaturated soil, volume change indices, constitutive relations, coefficients of volume change, oedometer tests.

Effects of coagulation condition on consolidation of soybean protein coagulate.

The modified coefficient of consolidation, Ce, of soybean protein coagulated was not significantly affected by the applied expression pressure but was greatly affected by the coagulation condition. The value of Ce was high when soybean protein was coagulated at a high temperature, with the calcium concentration to give about half of maximum amount of bound calcium, and with moderate stirring. The value of Ce was analyzed in terms of the average specific resistance to liquid permeation, and the coefficient of volume change, of the soybean protein coagulate.

In-Situ Volume-Change Properties by Electro-Osmosis - Theory

The basic concept involves incorporation of a simple electrode system in a field probe, measurement of pore-water pressure changes at the electrodes as a function of time in response to a DC field, and measurement of the electro-osmotic flow rate of water. Mathematical solutions for pore-water pressure responses for different electrode geometry and drainage conditions at the electrodes are presented dimensionless form, so that measurement of pore-water pressure responses at the electrodes as a function of time for a relatively short period should enable computation of the coefficient of consolidation, c sub v and the ratio of the coefficient of electro-osmotic conductivity to hydraulic conductivity,k sub e/k sub h. Unique solutions for k sub e, k sub h, and the coefficient of volume change, m sub v, are shown to be possible using measured electro-osmotic flow rate in a closed loop between electrodes and comparison with theory. (AUTHORS)