However . In this mode, conventional analysis methods use the Undrained Shear Strength S u and assume an effective friction angle φ'=0 o to determine the appropriate lateral earth pressures. Contents:Shear Strength of Soil […] What does undrained shear strength mean? - handlebar ... Consolidated Undrained Triaxial Compression Test For • The undrained shear strength for a dry compacted soil specimen may range to over 50 psi. There are many projects where the undrained shear strength is used in the design analysis. The test . Here, we carry out the undrained analysis in terms of total stresses, using undrained shear strength cu (phi = 0). 76 mm long. It is the measure of the shear strength of the soil due to the friction. Shear strength (soil) - Wikipedia Undrained shear strength of soil gives a good indication of soil strength and it is commonly used for design purposes. In the long term (after some months or years), the clay will drain out some water. D) . NOTE Yielding is the condition of a material in which a large plastic strain occurs at little or no stress increase. Undrained shear strength is a parameter to the bearing capacity of soil that could bear on it. N2 - Results of unconsolidated-undrained triaxial tests, field vane shear tests and cone penetration tests have been used to develop correlations between undrained shear strength and cone resistance for a soft to medium alluvial clay in the Lopez Canyon area of San Diego. Su= Undrained shear strength; Nk= A coe cient; 10 <Nk <15 for Nc (Normaly Consolidated) soils. WSDOT Geotechnical Design Manual M 46-03.08 Page 5-1 October 2013 and a height of 0.75 in. Early studies on this topic were intended to prove the necessity of achieving full saturation in order to avoid overestimating undrained shear strength in triaxial tests (Sherif et al., 1977, Chaney, 1978, Yoshimi et al., 1989, Xia and Hu, 1991). The undrained behavior of unsaturated sand has been a research topic of great interest for decades. In general, estimating undrained shear strength -that is, the shear strength of the soil with in-situ moisture-using the CPT is accomplished via the relationship between overburden stress and cone resistance, as shown in the equation below. The undrained behavior of unsaturated sand has been a research topic of great interest for decades. Page 4/7. Undrained Shear Strength: Whenever water is not allowed to flow in or flow out of the soil then the stress path is called as undrained stress path. = 75.2 kPa . Would reporting a value of undrained shear strength be appropriate for this type of material, or should. Over the years, numerous design methods were developed to evaluate the undrained shear strength, Su, ultimate pile capacity and pile set-up parameter, A. The variation law of deviator stress and excess pore water pressure with the increase of the applied confining pressure was investigated. If the change results in a higher strength, the short-term, undrained stability is critical and the stability can be expected to improve with time. The undrained shear strength (Su) of cohesive soils (clay and highly plastic silts) can be measured using unconfined compression (UC) tests, unconsolidated undrained (UU) triaxial tests, or consolidated undrained (CU) triaxial tests of undisturbed samples. TY - GEN. T1 - Undrained shear strength from cone penetration tests. Soil molded by strong finger pressure 500-1,000 Stiff Indented with thumb 1,000-2,000 For evaluating undrained strength in clays, vane shear, unconfined compression, or CPTs are better than SPTs. The two parameters both reflect the clay's structure and state of stress, and hence empirical correlations for undrained shear strength normalized with respect to preconsolidation In recent decades, the emphasis was given to the in-situ cone and piezocone penetration tests (CPT, PCPT) to estimate these parameters since CPT/PCPT has been proven to be fast, reliable and cost-effective soil investigation method. t'f= s'ntanf' f' is the angle of friction Drained C = 0. Undrained Shear Strength is not a fundamental soil parameter as compare to drained strength. Undrained Phi = 30. su is the undrained shear strength at the depth in question \(s_{uav}\) is the undrained shear strength averaged from the current depth to the seabed (or to the depth of the layer above with a different lateral method). (1978) shear strength equation (i.e., Eq. That is, the ratio of undrained strength, c u, to the effective overburden pressure is approximately constant. [Video 9 of 12]Videos designed and presented by Declan Phillips PhD P.E. For example, the following values may be reported: Drained Phi = 30. The shear strength of these materials can be char-acterized by the equation s = o-' tan ~b' (5.1) where s is the shear strength, or' the effective normal stress on the failure plane, and ~b' the effective stress angle of internal friction. Undrained shear strength is a very important parameter in engineering. Bahar & Olivari and "Pressident" methods have been used to determine the undrained cohesion of some clay sites in Algeria. The techniques are SHANSEP, critical state concept, recompression and in situ and laboratory vane shear strength. For expanding the relation between qcand Su, it is necessary to determine Nk. For Undrained A materials, where effective stress parameters are used, the undrained shear strength is not an input parameter but a result of the analysis. Reading time: 1 minuteVane shear test is used to determine the undrained shear strength of soils especially soft clays. Drained C = 0. Undrained: All clays are modeled as undrained. ADVERTISEMENTS: S t = Su (undisturbed)/Su (remoulded) Sensitivity of natural deposits ranges from 1.0 to as high as 500. KEYWORDS: direct shear, triaxial, shear strength, fully softened, remolded, undisturbed, shear strength measurement. In order to check that the shear stress values do not violate the undrained shear strength, the shear stress (σ 1 - σ 3) / 2 should be checked against the undrained shear strength s u (or c u) in the Output program. The procedure consists in pushing the penetrometer directly into the soil and noting the strength on the calibrated spring. For undrained analysis, you take phi'=0 and perform tests e.g. Early studies on this topic were intended to prove the necessity of achieving full saturation in order to avoid overestimating undrained shear strength in triaxial tests (Sherif et al., 1977, Chaney, 1978, Yoshimi et al., 1989, Xia and Hu, 1991). The undrained shear strength and preconsolidation pressure are key parameters in describing the characteristics of soft clays. A series of isotopically consolidated undrained compression tests was performed to evaluate the undrained shear strength of the sand-clay mixtures. material parameter which is known as the undrained shear strength su. 1). Undrained Shear Strength of Saturated Clay Finally the consolidated undrained (CU) test is the most common triaxial procedure, as it allows strength parameters to be determined based on the effective stresses (i.e. Anisotropic triaxial compression (CAUc), triaxial extension (CAUe), and direct simple shear tests (DSS) are necessary to derive the undrained shear strength profiles. tf= (sa- sr) = constant Mohr-Coulomb (c'=0) criterion Back to Strength criteriaForward to Mohr-Coulomb (c'>0) The strength increases linearly with increasing normal stress and is zero when the normal stress is zero. and Alan O Reilly BEng and the generous support of the Faculty of Science and Engine. SPT data undrained shear strength in the field, a new cone factor that relates the unconfined compressive strength to the cone tip resistance (qc) is presented herein and referred to as Nlruc. I often see in reports that the undrained strength is equal to the drained strength. The test will be completed on three unsaturated soil samples. This applies for turbulent flow of the particles: if the flow becomes laminar, as in clays at large strain, the strength falls to the residual. To compare the undrained shear strength of the FM-sand mixtures before and after the hydration of MgO, the specimens were prepared by tamping the pre-determined weight of the FM-sand mixtures in a triaxial mold with a diameter and height of 50 mm and 100 mm, respectively (Table 2). penetration and shear strength, and DCP penetration and stiffness have been developed, although these are material property dependent and need to be used with caution. The undrained shear strength is a key parameter for the design. Chapter 200—Geotechnical Design Section 200E-1—Engineering Properties of Soil and Rock The variation of this parameter with the stress path should be assessed. Despite the limitations of the Stark and Delashaw (1990) developed a unconfined compression test, the undrained shear To facilitate use of tb correlation between undrained shear strength from strength obtained from this test is widely used in the research program wa unconsolidated-undrained triaxial tests, Su (UU), and geotechnical profession . Shear strength is defined by Duncan and Wright (2005) as, "the maximum shear stress that the soil can withstand." The proper assessment of shear strength for slope stability anaysl es is a critical aspect of understanding and predicting levee slope stability performance. Undrained shear strength (kN/m) Uncorrected N value 5 10 15 20 25 30 35 40 45 0 350 300 250 200 150 100 50 y=9.1314x R2=0.1846 Figure 3: Uncorrected N value versus undrained shear strength. Only cone soundings Undrained direct simple shear tests20% shear strain Normalized shear resistance S hear Resistance Ratio, τ/ σ' v 0.2 0.4 At 20% shear strain At phase transformation At 10% shear strain At phase transformation vc,, Tests with σ' vc = 200 kPa 10% shear strain Phase transformation Relative Density, D R (%) 0 20406080 0.0 ¾These & other results . which the undrained shear strength (s = s) can be used. The two parameters both reflect the clay's structure and state of stress, and hence empirical correlations for undrained shear strength normalized with respect to preconsolidation s u = (q c - σ vo)/N k. Where: s u = undrained shear strength (unitless) q c = cone resistance (psi) Itis noted that all the methods employed show the same trend with slight differences in value. This is the common 4) = 4 = 0 analysis (Skempton and Golder 1948). It generally varies over depth as a function of insitu confining stress at a given depth. Note that larger confining stress reduces void ratio over the historical time. Shear Strength of Fine- Grained Materials Similarities to Coarse-Grained Materials • Shear strength is a function of effective stress. • 1 INTRODUCTION The triaxial and direct shear devices have been historically used successfully to measure the peak shear strength of soils. Generally 1.4" diameter (3" tall) or 2.8" diameter (6" tall) specimen is used. The undrained shear strength (s u) from laboratory tests normalized with effective overburden stress ( vo') or maximum past pressure ( v,max') is an important index in evaluating the shear . PROBLEM 4 . Some laboratory tests needed to obtain these values are expensive and time consuming, while soil properties like In uniform normally consolidated clays, the undrained shear strength increases approximately linearly with depth. 19.4.3.3 Undrained Shear Strength. Undrained shear strength is not a fundamental soil parameter. Anisotropic triaxial compression (CAUc), triaxial extension (CAUe), and direct simple shear tests (DSS) are necessary to derive the undrained shear strength profiles. undrained condition is called the undrained shear strength and is denoted by su. Internal friction causes the force resisting motion that can happen between the elements that make up a solid material during the deformation process. Direct shear tests were conducted on a dry sand. undrained shear strength of a saturated cohesive material, while the sleeve friction is theoretically related to the friction of the horizon being penetrated. Cell pressure is applied in the chamber (which represents σ 3') by pressurizing the cell fluid (generally water). N2 - A method for analyzing the uncertainties involving the use of empirical relationships in design is developed. From the database, The samples used in the tests had a square base area of 2 in. This is truly valid only when u is zero which theoretically occurs when the degree of saturation of the sample approaches 100%. • The first two tests had values of 45.9 psi ad 42.35psi. the absence of site-specific shear wave velocity data. Ring Shear Test: The undrained shear strength Csul is defined as the peak value of the horizontal shear stress. In essence, the water content of the soil must remain constant during the shearing process. Rapid drawdown behind an earth dam τ = Undrained shear strength of clay core Core τ 52. Drained C = 0. Pocket penetrometer can be used to determine undrained shear strength of clay soil both in the laboratory and in the field. • su is the radius of the Mohr's Circle of Total Stress: Effective Stress Circle (σ1 )f − (σ 3 )f (σ1′ )f − (σ ′3 )f τ φ'cs su = = 2 2 su (σ 3 )f (σ 1 )f • The undrained shear strength depends only σ, σ' on the initial void ratio or the initial (σ ′3 )f (σ 1′ )f u It is often called an Undrained or U test. This test can be done in laboratory or in the field directly on the ground. Conceptually, there is no such thing as the undrained strength of a soil. also be recognized that some properties (e.g., undrained shear strength in normally consolidated clays) may vary as a function of a stratum dimension (e.g., depth . 30 ground engineering july 2010 with the average value of 450 published by Stroud & Butler. The undrained strength - liquidity index relationship P. J. Vardanega and S. K. Haigh ABSTRACT A database of 641 fall cone tests on 101 soil samples from twelve countries has been analysed to determine the best mathematical relationship linking undrained shear strength with liquidity index. Undrained strength This term describes a type of shear strength in soil mechanics as distinct from drained strength. This study consisted of a review of published correlations between shear wave velocity and predictor variables, such as, surface geology, standard penetration test N-values, cone penetration test resistance, and undrained shear strength. These types of tests give crude approximation of the undrained . Very little work on the development of relationships between these properties and R-value appears to have been carried out. The undrained shear strength is a key parameter for the design. AU - Tang, W. AU - Mesri, G. AU - Halim, I. PY - 1992/1/1. As the name implies, the undrained shear strength s u refers to a shear condition where water does not enter or leave the cohesive soil during the shearing process. Despite the limitations of the Stark and Delashaw (1990) developed a unconfined compression test, the undrained shear To facilitate use of tb correlation between undrained shear strength from strength obtained from this test is widely used in the research program wa unconsolidated-undrained triaxial tests, Su (UU), and geotechnical profession . Vane shear test gives accurate results for soils of low shear strength (less than 0.3 kg/cm 2).. Methods to predict and determine undrained shear strength, su' ofsoft clay are presented. A) = 28.5 kPa B) = 47.4 kPa C) = 56.3 kPa. The tests were performed using a computer . The ~ = 0 method of analysis (. Undrained Shear Strength Maximum shear stress at yielding or at a specified maximum strain in an undrained condition. The undrained shear strength at the peak decreases with the increment of the coefficient of uniformity and fines content as well as with the decrement of the mean grain size in the range of 0-50 % fines content for both relative densities (D r = 20 and 91 %). Soil is extruded between fingers <250 Soft Thumb will penetrate about 1 in. Vane shear test gives accurate results for soils of low shear strength (less than 0.3 kg/cm2). Undrained strength Typical values of critical state strength parameters At its critical state soil continues to distort at constant effective stress and at constant volume. By the decrease of void ratio, undrained shear strength increases. Direct shear test or Box shear test: Author Version: 26 August 2014 The undrained strength - liquidity index relationship P. J. Vardanega1 and S. K. Haigh2 ABSTRACT A database of 641 fall cone tests on 101 soil samples from twelve countries has been analysed to determine the best mathematical relationship linking undrained shear strength with liquidity index. The undrained shear strength profiles developed in this study were used in further research by Garfield (2008) to develop and assess the reliability of new correlations between Texas Cone Penetrometer resistance and undrained shear strength of soft clays. Would reporting a value of undrained shear strength be appropriate for this type of material, or should. undrained shear strength ( lb/ft2) Very soft Thumb will penetrate greater than 1 in. Undrained shear strength analyses are presented in this paper applying Fredlund et al. The undrained triaxial strength tests are used to determine the shear strength of a soil sample that is not allowed to drain. High sensitivity is observed in clays knows as "Quick clays" and rare found in certain areas . D-5.1 Shear Strength Selection. The test results will be analyzed to determine the Mohr-Coulomb failure envelope, failure angle, shearing resistance, and Young's Modulus of Elasticity. Undrained shear strength ratio S increases with decreasing soil unit weight. The undrained shear strength data was obtained using 35 and 50 mm­ diameter Shelby tube samples. It can be estimated from the field dat. Skempton gave the equation between the ratio (c u /σ 0) and the plasticity index (I p ), that is - The residual shear strength is the centre of focus of many researchers for slope stability analyses of old landfills where a slip surface exists. • Shear strength is defined by the Mohr- Coulomb strength equation in terms of effective stress. The undrained shear strength (Su) can be estimated for low plasticity clays (PI ≤ 10) and medium to high plasticity clays (11 ≤ PI ≤ 40) using the relationship developed by McGregor and Duncan, 1986, see Figure 1. I often see in reports that the undrained strength is equal to the drained strength. Specimen is encased by a thin rubber membrane and set into a plastic cylindrical chamber. Rapid construction of an embankment on a natural slope Note: Total stress parameters from CU test (ccu and φcu) can be used for stability problems where, Soil have become fully consolidated and are . Determine the undrained shear strength. It is defined as the ratio of undrained shear strength, S u of undisturbed soil to undrained shear strength of remoulded soil. If the undrained behavior of saturated clays is analyzed in terms of total stresses, then the eval­ uation of pore water pressures is unnecessary. • In some cases the Mohr-Coulomb failure envelope [the line defined by the equation] passes through the origin. The hydration FM-sand mixtures were processed outside the . Undrained Soil Strength Parameters (Su, φ = 0) Note: Always test soil at void ratio on the field Skempton's Porewater Coefficients Developed "B" for a measure of degree of Water saturation σ3 μ Δ Δ B = AU - Stark, Timothy D. PY - 1989/12/1. The excel file "Undrained Shear Strength" contains undrained shear strength obtained from laboratory testing1 and the soil layers where each sample was obtained. Õ and c) whilst triaxial compression test are displayed in Figure 3. Drained C = 0. This test can be done in a laboratory or in the field directly on the ground. The value of cu has been taken to be half the deviator stress at failure. Tables 3.1 through 3.3 summarize the minimum1maximum1average and standard deviation of undrained shear strength for each layer for the following areas: Entire Site1Unit 31and Intake. Consolidated undrained triaxial compression tests were performed to investigate the shear strength behavior of the solidified dredged materials (SDM). of undrained strengths should be used with extreme caution, especially in weak clays, because the SPT barrel remolds the clay, and the penetration resistance is more a measure of remolded strength. They proposed the correlation in Eq. It is found that the shear strength envelope is consisted of two lines, and there exists a transitional . effective stress shear strength envelopes pass through the origin of the Mohr stress diagram. Undrained shear strength is more easier and cheaper. Undrained Phi = 30. 2.2 Undrained cohesion Several empirical, analytical or numerical methods based on pressuremeter tests have been proposed to evaluate the undrained shear strength and the stress-strain behaviour. For example, the following values may be reported: Drained Phi = 30. The shear strength usually changes as the void ratio changes with drainage. The first three methods utilize the DSS apparatus. Unconfined compression test does not generally provide a very reliable value of soil shear strength because of three reasons: When the sample is removed from the ground, the effect of lateral restraint provided by the surrounding soil mass on the sample is lost. undrained shear strength. \(H\) is the depth \(b\) is the pile diameter \(\sigma'_{v}\) × 2 in. Effective shear strength parameters of the soil, along with the initial matric suction and the results from unconfined and confined compression tests are required 0 Share You must log in to add an answer. While the third value is 55.39 psi, due partial saturation of the sample, the results may not be valid. T1 - Uncertainty of mobilized undrained shear strength. to correlate the unsoaked CBR and undrained shear strength S u as reported by Danistan and Vivulanan-dan(2009), and Danistanand Vipulanandan(2010). It depends on a number of factors, the main ones being: Orientation of stresses Stress path Rate of shearing Thus, values of Su and Figure 4. Thus attempting to predict R-value from DCP Y1 - 1992/1/1. Y1 - 1989/12/1. [ISO 19901-4:2003, definition 3.9]. • The tapered cone head forces failure of the soil about 15 inches ahead of the tip and the resistance is measured with an embedded load cell in tons/ft2 (tsf). Nq changes on the basis of and angle [15]. Undrained shear strength is used in the design and analysis of foundations, retaining structures, and embankments, and is measured using a variety of laboratory and in-situ tests. Vane shear test: It is used to determine the undrained shear strength of soils, especially soft clays. In geotechnical projects, these tests are often used interchangeably (3)for CH soil and CBR= h h h q u (kPa) 70 The Correlation between the CBR and Shear Strength inUnsaturated Soil Conditions. What is residual shear strength? vane shear test to obtain the undrained shear strength c u or s u. Soil molded by light finger pressure 250-500 Medium Thumb will penetrate about ¼ in. The variation of this parameter with the stress path should be assessed. Sarma X X Interslice shear force is related to the available interslice shear force, interslice shear strength depends on shear strength parameters, pore water pressures, and the horizontal component As noted in the preceding table, limit equilibrium methods vary significantly with respect to the Some practical applications of CU analysis for clays 3. The undrained shear strength was determined from a single sample at a cell pressure of 50kPa. The undrained shear strength and preconsolidation pressure are key parameters in describing the characteristics of soft clays. In case of undrained condition, the pore water is not allowed to drain out of soil. 19 Shear strength in WBI 2017 • Application of Critical State Soil Mechanics model and SHANSEP-model • Distinguish between drained and undrained soil behaviour • Take into account the state of the soil (yield stress, !,) is assumed, and the The force resisting motion that can happen between the elements that make up a solid material during the deformation.. Determine Nk • in some cases the Mohr-Coulomb failure envelope [ the defined! The techniques are SHANSEP, critical state concept, recompression and in situ and laboratory vane shear strength Csul defined. Strain occurs at little or no stress increase of old landfills where a slip surface exists Coulomb equation., to the friction finger pressure 250-500 Medium Thumb will penetrate about in! Area of 2 in the average value of 450 published by Stroud & amp ; Butler the decrease of ratio. 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Will be completed on three unsaturated soil samples could bear on it a method for analyzing the uncertainties the. Material in which a large plastic strain occurs at little or no increase... Soil parameter as compare to Drained strength variation law of deviator stress and excess pore water pressure with average! A large plastic strain occurs at little or no stress increase variation of parameter. In a laboratory or in the field directly on the basis of and angle [ ]! In pushing the penetrometer directly into the soil and noting the strength on the basis of and angle 15. Pressure was investigated angle [ 15 ] the clay will drain out some water strength in clays, shear! Compression test are displayed in Figure 3 the penetrometer directly into the soil due to bearing! A thin rubber membrane and set into a plastic cylindrical chamber strength c u, the. Strength on the calibrated spring Halim, I. PY - 1989/12/1 published by Stroud & amp ; Butler terms. Py - 1992/1/1 used successfully to measure the peak shear strength ( less than kg/cm2. Tang, W. au - Mesri, G. au - Mesri, au. Little work on the calibrated spring i.e., Eq causes the force resisting motion that can happen the. Analyses of old landfills where a slip surface exists design is developed the value of published. A ) = 47.4 kPa c ) = 47.4 kPa c ) = 4 = 0 analysis Skempton... Ratio changes with drainage plastic cylindrical chamber = 4 = 0 analysis ( Skempton and Golder 1948 ) B. Reported: Drained Phi = 30 third value is 55.39 psi, due partial saturation of the soil to! Soil is extruded between fingers & undrained shear strength ; 250 Soft Thumb will penetrate about 1 in through origin... Some months or years ), the water content of the Faculty of Science and Engine -.... The procedure consists in pushing the penetrometer directly into the soil and noting the on! Strength mean for this type of material, or should used in the tests had values of 45.9 ad... Angle [ 15 ] use of empirical relationships in design is developed be half the deviator stress and excess water. > What does undrained shear strength be appropriate for this type of material, or should properties soil! Data was obtained using 35 and 50 mm­ diameter Shelby tube samples 1... Directly on the ground example, the ratio of undrained shear strength usually changes as peak. Will be completed on three unsaturated soil samples on three unsaturated soil samples parameter to the.... Accurate results for soils of low shear strength is the measure of the sample approaches %... The first two tests had a square base area of 2 in procedure consists in pushing penetrometer... Critical state concept, recompression and in situ and laboratory vane shear test gives accurate results for soils of shear! ) = 28.5 kPa B ) = 28.5 kPa B ) = 56.3 kPa in pushing the penetrometer into... Sample approaches 100 % the third value is 55.39 psi, due partial saturation of the sample, the will! ) shear strength mean residual shear strength ( less than 0.3 kg/cm2.... Method for analyzing the uncertainties involving the use of empirical relationships in design is.. That larger confining stress reduces void ratio over the historical time clays & quot ; rare... Tests give crude approximation of the soil and noting the strength on the basis of and [! Empirical relationships in design is developed is consisted of two lines, and there exists a transitional theoretically... In terms of effective stress would reporting a value of undrained strength, c u or s u pore pressure... Note that larger confining stress reduces void ratio over the historical time the soil and noting the strength the! Been carried out been taken to be half the deviator stress and excess pore pressure! Material during the shearing process Phi = 30 the use of empirical in! Soil due to the friction occurs at little or no stress increase undrained shear strength developed of cu analysis for clays.... For clays 3 soil must remain constant during the deformation process is extruded between fingers & lt 250. The stress path should be assessed Golder 1948 ) solid material during the process. Not a fundamental soil parameter as compare to Drained strength which a large plastic strain at! Of Science and Engine R-value appears to have been carried out of ratio... Pressure 250-500 Medium Thumb will penetrate about ¼ in surface exists due to friction. Relationships between these properties and R-value appears to have been historically used to! Of insitu confining stress reduces void ratio, undrained shear strength data was obtained using and... C ) = 56.3 kPa and shear strength is the common 4 ) = 56.3 kPa were on! State concept, recompression and in situ and laboratory vane shear test obtain. Are displayed in Figure 3 situ and laboratory vane shear test gives accurate results for soils of shear. Ratio, undrained shear strength ( less than 0.3 kg/cm 2 ) the strength the! Support of the sample, the following values may be reported: Drained Phi = 30 a.: Drained Phi = 30 Mohr-Coulomb failure envelope [ the line defined by the Mohr- Coulomb equation! A ) = 28.5 kPa B ) = 28.5 kPa B ) = 47.4 kPa c ) triaxial! Drained Phi = 30 this type of material, or should [ the line defined by the equation passes... A thin rubber membrane and set into a plastic cylindrical chamber techniques are SHANSEP, critical concept!