Shear Box Research Articles

Investigation of effect of water content on railway granular supplementary layers

Purpose. To determine the relationship between water content of continuously graded granular supplementary layers for railway substructure and their inner shear resistance and load bearing capacity. Methodology. Four different samples were produced as standard granular products from andesite. Two of them are common base courses for road construction in Hungary, the other two are common railway supplementary layers. The author performed laboratory measurements (multi-level shear box tests) that are adequate for the evaluation of inner shear resistance. The measurements of load bearing capacity and Proctor tests were executed in the laboratory of Colas Hungaria Ltd. The author performed measurements with the optimal water content values of each sample, as well as lower and higher values than them. This can show how the given granular material is sensible to the change of water content. Findings. It was proved that the granular supplementary layers, which are standardized products in road construction (as base courses), also seems to be adequate in railway construction; they are not so sensible to the variation of their water content. It does not mean that the other two granular layers are not adequate for railway substructures, but the application of road products have to be considered as substitute products. Originality. The author tried to emphasize the adequacy of rock mining for construction of ballasted railway tracks, as well as the optimal use of mineral wealth in every country with its results. Practical value. The obtained results of the present paper can be useful in the area of rock mining, and railway infrastructure engineering. During construction procedures the optimal water content values should be taken into considerations for compaction to be able to reach maximal compactness (density), but too high water content has to be avoided, which is based on the results. They can be also considered in the design phase.

Use of the Cam-Clay Model in Finite Element Calculations after Identification of Soils from Simple Mechanical Tests

In order to make the use of complex elasto-plastic behavior models more accessible, we attempted to identify the Cam-Clay model in two samples of tropical and lateritic soils (from Senegal/West Africa) from casagrande box shear and oedometric tests. This methodology was used as a substitute for triaxial trials. In this article, we first verify the test results by the finite element method with the Optum software. We use a simulation of the tests with the modified Cam Clay model as the behavior model. Then, we simulate the oedometric test on tropical soils with the Castem software and also use the modified Cam Clay model. These calculations make it possible to write the criterion of plasticity of the material starting from the expression of the surface of load while passing by the calculation of the volumetric and deviatoric stresses.

ENGINEERING PROPERTIES OF LATERITIC SOIL IN OTUN AREA, EKITI STATE, NIGERIA

Lateritic soils at Otun Ekiti, Ekiti state, southwestern Nigeria were investigated with respect to their geotechnical properties and their suitability for subgrade and sub – base construction materials. Four disturbed lateritic soil samples (sample A, B, C and D) were selected for the various laboratory techniques. The grain size analyses, the specific gravity tests, the atterberg limit tests, compaction, California bearing ratio and shear box tests were carried out on the samples. The grain size analysis shows that sample A is gravelly silt-clayey sand. Sample B is silt – clayey gravel composition. Sample C is gravelly silt-clayey while Sample D is silt-clayey gravel. Atterberg consistency limit test indicate that sample A has 30.0%, liquid limit 19.5% plastic limit, 10.5% plasticity index, 9.1% shrinkage limit. Sample B has liquid limit of 27.0%, 16.2% plastic limit, 10.8% plasticity index and 7.4% shrinkage limit. Sample C has a liquid limit of 32.4%, plastic limit of 15.6%. It has a plastic index of 16.8%, Shrinkage limit of 9.7% while Sample D has a liquid limit of 36.2%, plastic limit of 17.7%. It has a plastic index of 18.5% and 11.1% as shrinkage limit. Thus, the soil is classified to be intermediate plasticity which can be used for sub – grade and sub – base materials. The soil samples are above the activity (A) line in the zone of intermediate plasticity (CL) which suggests that they are inorganic soils. Based on engineering use chart, the workability as construction engineering is good to fair particularly as erosion resistance in canal construction. However, the high shrinkage limit may also reduce erosion in this area because of cohesion of the plastic clay material. The California Bearing Ratio (CBR) values are within 2 – 3% (mean = 2.75%) and 2 - 4% (mean = 2.75%) in sample A and sample B respectively while California Bearing Ratio (CBR) of 2 - 4% (mean = 2.75%) and 2 – 3% (mean = 2.75%) in sample C and sample D respectively. This implies that the materials can be used as a sub-grade to base course material for support of flexible pavements. The compaction tests for the optimum water content for sample A is 15.0% and 13.0% for standard and modified proctor respectively. The standard and modified proctor for sample B is 15.0% and 14.0% respectively. The compaction tests for the optimum water content for sample C and D is 15.0% and 14.0% for standard and modified proctor respectively. The compaction tests for Sample A indicate a higher fine fraction and thus a higher optimum moisture content while sample B, C and D has higher coarse fraction with lower optimum moisture content. The cohesion falls within 70-90Kpa (mean = 79Kpa) and the angle of internal friction ranges from 260 - 320 with mean of 280 for standard and modified compaction energies respectively. The results obtained from geotechnical analysis suggest that the soil is good to fair as erosion resistance in canal construction because of its high bearing capacity and it can also be used as sub – grade and base course in road construction. Keywords: Lateritic soil, Construction, Erosional and Geotechnical.

The Effect of Freeze-thaw Cycles on The Geotechnical Properties of Clayey Soil Treated with Lime

Fine-grained soils (cohesive soils) exposed to freezing-thawing cycles exhibit to notable alterations ontheir physical and mechanical characteristics. The environmental conditions' influences on soil geotechnical properties are significant, especially when stabilized by hydrated lime. This study was carried out to explore the effect of freeze-thaw cycles on cohesive soil stabilized by various hydrated lime percentages (zero%, 5%, 10%, and 15%) by dry mass, which cured for 28 days at 30°C. One-dimensional consolidations, unconfined strength, and shear box tests were performed for untreated and treated soil samples subjected to 0, 1, 2, and 3 freeze-thaw cycles. Duplication of freeze-thaw cycles significantly impacts some geotechnical properties and decreases them such as LL, UCS, Cc, Cr, and C. The PL and ϕvalues of the samples treated by hydrated lime and subjected to freeze-thaw cycles observed to be increased, which were due to the important role of hydrated lime addition. It is concluded that the hydrated lime can be effectively utilized to minimize the impacts of freeze-thaw periods on shear strength and compressibility of cohesive soil.

Chemically induced changes in the geotechnical response of cementing paste backfill in shaking table test

Abstract Cemented paste backfill (CPB) is extensively used for underground mine support and/or tailings management. However, CPB behavior under cyclic loadings might be affected by the chemistry of its pore-water, which often contains sulphate ions. Till today, no studies have addressed the effect of sulphate on the response of CPB to cyclic loadings by using shaking table technique. This study presents new findings of assessing the effect of the sulphate in the pore water of CPB on its geotechnical response to cyclic loading by using shaking table. CPB mixtures were prepared (with and without sulphate), poured into a flexible laminar shear box, cured to 4 h, and then exposed to cyclic loading using one-dimensional (1D) shaking table. Several parameters (e.g. pore water pressure, settlement, lateral deformation, acceleration, electrical conductivity, effective stress, and liquefaction susceptibility) were monitored or determined before, during, and after shaking. Obtained results indicate that the sulphate-bearing CPB cured to 4 h can be prone to liquefaction under the studied conditions. However, sulphate-free CPB samples are resistant to liquefaction. These results are expected to contribute to a better understanding of the effect of water chemistry on the cyclic behavior of CPB, consequently enhancing the cost-effective design of CPB structures.

Frequency- and intensity-dependent impedance functions of laterally loaded single piles in cohesionless soil

This paper investigates the frequency-dependent pile-head impedance characteristics of a model soil-pile foundation system under large amplitude loads, inducing soil yielding. Testing was conducted on a scaled single pile embedded in sand under a 1g condition. A laminar shear box mounted on a unidirectional shaking table was used to house the soil-pile foundation system. Quasi-static loads and dynamic loads were applied to obtain the force–displacement relationships and pile-head impedance functions, respectively, through the pile head connected to a loading actuator providing fixity to the pile head in all directions, except horizontal. In the quasi-static case, loads with three different velocities were applied to study the rate-dependent characteristics of the lateral bearing capacity of the pile. The Stereo-PIV system was employed to measure the surface soil displacement around the pile. The lateral bearing capacity changed with the loading velocity, but the soil near the pile showed a consistent failure pattern despite a significant change in velocity. Lateral pile-head dynamic impedance functions were obtained for low-to-high amplitude harmonic loading for a wide range of frequencies. The dynamic stiffness was seen to converge to that of the secant static stiffness with an increase in the amplitude of the dynamic loading for all the excitation frequencies.

A novel experimental study to investigate the interface properties of rammed earth

Rammed earth is a monolith structure constructed by compacting partially saturated soil in layers within a formwork. Few studies have pointed out the lack of experimental data on rammed earth layer interface strength and their importance in design consideration. Currently available testing procedures such as shear box, triaxial, triplet, push-over and diagonal compression tests have their own limitations, mainly their cost, which make them unlikely to become a standard procedure. This paper introduces a wedge tool technique to explore interface shear strength properties with ease. Three pairs of metallic wedges with different testing inclination angles (45, 30 and 20°) were designed and tested for two soils. Specimens tested at these inclinations provide a combination of shear and normal stress acting on the interface. Tests on two different soils showed that the new device can measure cohesion and the angle of internal friction with a correlation coefficient higher than 0·8; the results were found to be consistent with values classically obtained for these kinds of materials. The indirect shear test procedure developed is a robust way of measuring shear parameters while being simpler and less expensive than existing devices.

Seismic wave input method for high earth dams considering the transmission amplification effect of the bedrock–overburden interface

The method for determining the input ground motion of concrete and earth dams on bedrock is not applicable to earth dams on overburden soil due to the transmission amplification effect of the seismic waves at the bedrock–overburden interface. Moreover, the free-field and artificial boundary parameters of the overburden foundation cannot be calculated using analytical methods because of the nonlinear characteristics of the soil under strong earthquakes. Therefore, the nonlinear variations in the artificial boundary parameters and the equivalent load with the dynamic shear strain of the soil must be considered. First, the influencing factors of the transmission amplification effect under different types of waves are analyzed. Second, a method for determining the input ground motion with consideration of the transmission amplification effect is developed. Then, the free-field response at the truncation boundary of the overburden soil is obtained on the basis of the shear box model. The equivalent nonlinear viscoelastic artificial boundary element attached to the boundary soil element of the overburden foundation is generated; the stiffness and damping matrix of the viscoelastic artificial boundary element change with the shear strain of the boundary soil element. Subsequently, a nonlinear wave input method suitable for overburden foundations is established. Finally, the error degrees of the seismic response of the overburden foundation–dam system with respect to the far-field artificial boundary are compared using the methods of nonlinear wave input, fixed and free boundaries, and the viscoelastic boundary combined with the equivalent inertial force input. The efficiency and accuracy of the nonlinear wave input are high. The influence degree of the ground motion considering the transmission amplification effect on the response of the earth dam is also analyzed. Moreover, the influence mechanisms of the dynamic parameters of the overburden soil and bedrock on the transmission amplification effect and the seismic response of the overburden–dam system are discussed.

Characteristics of void distribution and aggregate degradation of asphalt mixture specimens compacted using field and laboratory methods

Asphalt mixtures compacted in the field and in a laboratory show obvious differences in their internal structures, and this affects the evaluation of pavement performance. Hence, in this study, to find a laboratory compaction method most similar to the field method, the effect of the field method and multiple laboratory compaction methods on the internal structure of asphalt mixture specimens was investigated. First, based on the principle of keeping the same compaction degree, specimens cored from field specimens were prepared with six laboratory methods. Then X-ray computed tomography (X-ray CT) and digital image processing (DIP) technologies were used to analyze the internal structure of the specimens, including the spatial distribution and particle size of the voids, as well as the aggregate degradation. Finally, the similarity of the laboratory specimens to the field specimens was evaluated. The results indicated that the spatial distribution of the voids was affected by the compaction methods. The edge effect was different in specimens with different heights. The symmetry of the distribution curve of the air voids was affected by the distribution of the compaction effort. The void particles in a certain size range occupied most of the volume, and the size distribution of the void particles inside the specimens was affected by the compaction methods. In the compaction process of the static load method, the aggregates were constrained and seriously broken, while the dynamic load and the kneading action could protect aggregates from being broken. In general, the partial specimens compacted using a Superpave gyratory compactor (SGC) and a shear box compactor (SBC) were more similar to the field specimens than other laboratory specimens. This study offers a reliable basis for studying the internal structure of asphalt mixture specimens compacted using different methods and for guiding laboratory compaction based on the field method.

Shaking Table Tests and Numerical Analysis on the Seismic Response of Karst-Crossing Socketed Piles in Dry Sandy Soil Foundation

The foundation piles in karst areas have different mechanical properties from those in other areas. Targeting a critical highway bridge in a karst area, this paper designs two kinds of foundation pile models: friction pile, and KCSP, based on theories on dynamic tests. Then, shaking table tests were carried out to ascertain the features of pile strain distribution of KCSP under earthquakes. During the tests, a large laminar suspended shear box was adopted to mimic the boundary effect of soil. In addition, numerical simulations were conducted to disclose the effects of karst cave on pile strain. The test results indicate that: the peak strain of KCSP increased with the peak acceleration; For both KCSP and friction pile, the peak strain decreased first and then increased along the depth; The presence of karst cave can adversely affect the seismic response of foundation pile; The taller the karst cave, the larger the peak strain of the pile; the peak strain of KCSP was larger at the two ends, and smaller in the middle. The numerical analysis shows that: the peak strain of foundation pile in karst cave increased significantly with cave height; The peak strain of the pile passing through multiple caves was similar to that of the pile passing through only one cave, under the same cave height; But the multi-cave scenario differed from the single-cave scenario in peak strain distribution. The research results provide new insights into the seismic design of pile foundation of bridges in karst areas.

Use of concrete shear box for measuring the Bingham parameters of SCC

Flow characterization and controlling of fresh property of Self-compacting concrete (SCC) is most critical than conventional vibrated concrete (CVC) since slight variation in ingredients can have adverse effect on fresh properties, strength and durability of hardened concrete. Therefore rheological studies are important to overcome the insufficiencies of empirical tests.In the present work, the Bingham parameters of SCC were assessed by using the new instrument concrete shear box. The mixes were designed based on absolute volume concept starting with a volumes of paste (Vp). Three different Vp 0.37, 0.39 and 0.41 with water contents of 175 and 195 lt/m3 and cement contents of 300 and 450 kg/m3 along with GGBS as filler was used. Normal stresses of 0.10, 0.20 and 0.30 MPa along with three different displacement rates of 1, 5 and 15 mm/min were used under static load condition. The result indicate the usefulness of concrete shear box, as an additional instrument for measuring the Bingham parameters of SCC viz., yield stress and plastic viscosity and invalidates the use of Bingham model with higher flowability of 800 mm and beyond.

Testing and modeling of frozen clay–concrete interface behavior based on large-scale shear tests

The shear behavior of the frozen soil−structure interface is important for accurately predicting the interface responses of structures adopted in the cold regions. The purpose of this study is to experimentally and theoretically investigate the shear behavior of frozen clay–concrete interface under engineering conditions. A large-scale direct shear apparatus with a temperature-controlled shear box is used to test the interface behavior. Test specimens consisting of a cement concrete block and frozen soil with initial water content ranging between 14.6% and 24.6% were prepared at different conditions of temperatures (15.4 to −9.8 °C), shear rates (0.03–0.9 mm min−1), and normal stresses (50–200 kPa). It is found that the peak shear strength is linear developing with increasing of normal stress, initial water content, and temperature. It increased from 67.7 to 133.3 kPa as the initial water content increased from 14.9% to 24.6% at temperature of −6.8 to −6.6 °C, and it increased from 51.2 to 80.6 kPa with temperature decreasing from 15.4 to −9.8 °C at initial water content of 14.6%–14.9%, furthermore it has a power law relationship with shear rate. The final vertical displacement increases with the decreasing temperature, and increasing initial water content. While, it is slight or could be ignored at lower shear rates (e.g. 0.03 mm min−1 and 0.15 mm min−1) and it is −0.25 mm and −0.28 mm at shear rate of 0.3 mm min−1 and 0.9 mm min−1, respectively. In addition, the evolution of vertical displacement also varies with test condition, the growth rate at beginning increases with increasing initial water content and decreasing temperature or ice content, which is because of the ice film effects the particle size. Moreover, a disturbed state concept model combined with linear and nonlinear characteristics is developed to describe the interface shear behavior. The disturbance D reflects the interface mechanical response and responds differently trend for different test conditions, increasing faster with increasing temperature and decreasing initial water content or shear rate. The testing results, including the test and model results, can be used to simulate the performance of engineered geotechnical assets such as earth dams or irrigation channels with concrete linings in cold regions.

Determination of the seismic signatures of landslides in soft soils: A methodology based on a field scale shear box

We present a novel field experimental setup that can be used for studying the characteristics of landslide seismicity. The setup consists of a concrete, filled with soil, cylinder that moves along a surficial soil corridor. The emitted seismic signals are due to soil friction. The cylinder acts as an upscaled sheer-box allowing control over a number of parameters: the magnitude of normal stress on the failure plane, the degree of saturation and the type of soil. This allows for the simulation of soil friction within, or between, different geological layers under different conditions. Results are site specific, but can be easily reproduced for any geological environment. We validate this methodology by comparing the spectral characteristics of the signals emitted by the movement of the cylinder to those induced by a controlled failure of a 2.5 m high vertical face at a nearby site with very similar geology. We find a very good agreement between the two. This methodology can be used as a site investigation tool for the optimization of the deployment geometry of seismic networks for landslide monitoring, as well as to inform machine learning algorithms on automatic detection and classification of recorded signals during seismic monitoring of landslides.

Behavior of Fully Encapsulated Cable Bolt in Various Double-Shear Methods and the Sequence of Wire Failure in the Newly Developed Shear Apparatus

The use of long-tendon ground support elements (cable bolts) is now a common practice in modern underground coal mines, hard rock mines, tunnels, and other underground structures. The paper briefly introduces the development of test methods for rock and cable bolts, including single- and double-shear methods, in the last 30 years and focuses on the novel development of the fourth generation of cylindrically shaped shear test apparatus (MK-IV Double Shear Box) for assessing tendon performance in shear based on the experience gained from the development of previous versions of shear experiment apparatus. The results were compared with similar test findings using a rectangular-shaped double-shear apparatus with and without friction across joint faces. The sequence of wire failure was studied by using the newly developed double-shear test apparatus, and the performance of abnormal phenomena in the double-shear tests was analyzed. The sequence of wire failure can be inferred based on the positive and negative values of strain gauge readings, and the wire of cable bolt under shearing may be broken in the joint area. The failure possibly occurred from one side to the other instead of from top to bottom. The modified double-shear test apparatus with a long section of concrete cylinder was proposed to conduct further research on cable bolt debonding.

Assessment of pipe powder in soil improvement applications: an optimization by response surface methodology

Experimental design methods have become very popular approaches in engineering studies thanks to providing some advantages to reduce time period of experiments. In this study, shear strength characteristics of sandy soils were investigated by using central composite design (CCD) approach which is one of the response surface methods. Shear box test results performed at different time intervals were used to design CCD. In model application, the effect of time period under constant load (TPUL) and pipe powder (PP) content (8–12–16%) were used as independent factors to observe shear strength characteristics. Regression equations, variance analysis results, and factor interactions of response variables were used as statistical parameters to analyze CCD performance. Experimental results showed that TPUL is a significant parameter. CCD analysis also determined the importance of TPUL and suggested 14 days as the best time period. CCD results also showed that the optimum PP content can be selected as 12%.

Effect of interparticle behavior on the development of soil arching in soil-structure interaction

Direct shear tests have been commonly used to study the frictional stresses during pipe-jacking. Particle angularity and mineralogy will influence the shear strength with apparent cohesion contributing to the arching effect during soil-structure interaction via pipe-jacking. Past researchers found it challenging to physically study particle behavior along the shear band during shearing due to the opaque nature of the equipment. This study used an original transparent shear box to conduct direct shear tests on tunneling rock spoils of sandstone and shale. Sequential images were captured during shearing and analyzed using GeoPIV software to demonstrate localized activities which were found to influence the apparent cohesion. Furthermore, the findings were successfully used to assess the arching phenomenon observed during pipe-jacking and other established pipe-jacking case studies. Rounded particles with strong mineralogy were found to be more likely to produce an arching effect as compared to angular particles with weaker minerals.

Large direct shear testing to evaluate the interaction behaviour of murrum soil and geosynthetics for the reinforced soil construction

Soil is being considered to be a natural resource as a construction material. At few circumstances, it exhibits poor performance due to inadequate engineering properties. In this regard, many researchers have been making constant endeavours to put forth innovative ideas to make the soil to function as per the requirement. These research works are effective in suggesting new techniques to improve its properties to make poor soils suitable for various types of constructions. The ‘Reinforced Soil’ technique was first conceived by Henry Vidal in 1966. It is considered to be a cost effective solution in the field of construction. The simple mechanism of reinforced soil and economy in cost of construction and less time for project implementation has made it an instant success. The technique is well appreciated by many researchers and field engineers alike for ease of making a variety of temporary as well as permanent structures. Further, with the advent of new reinforcing materials such as geosynthetics, there has been increasing usage of application of this technique for various types of infrastructure facilities. Soil–reinforcement interaction is one the governing factors in the design of reinforced soil structures. This interaction between soil and geosynthetic materials is influenced by interfacial frictional forces developed between soil and geosynthetic material. In this paper an attempt was made to investigate the effectiveness of three different types of reinforcing materials viz., woven geotextile, non–woven geotextile and geogrid by taking into consideration of the interfacial frictional forces developed with individually with murrum soil. A laboratory study was undertaken with large direct shear box to evaluate interaction behaviour and the development of interfacial frictional forces by considering shear stress. The experimental study could offer a probable solution for relative performance of three different types of geosynthetic reinforcement with varied tensile strength in terms of the shear stress parameters.

Seismic Performance of Footings on Stone Columns Treated Dry Sand Beds

An extensive experimental study has been carried out to study the seismic performance of footings on stone columns treated dry sand beds. Physical models have been prepared in a laminar shear box of size 1 m3 on the shaking table which has a single degree of freedom motion for representing horizontal shaking action under seismic vibrations. Effect of the configuration of stone columns, aspect ratio of footing, relative density of sand bed, frequency and peak ground acceleration (PGA) of cyclic input motion on vertical settlement of footing has been studied. Optimum length of stone columns has been found to lie between 13–16 times the diameter. Direction of shaking perpendicular to length of footing has been found to be more critical. Effect of aspect ratio has been found to be more pronounced at larger PGA. Influence of the frequency on response of footings has also been quantified.

Friction and Shear Properties of Pine Biomass and Pellets.

Knowledge on the mechanical properties of granular biomass is important for the design and efficient operation of equipment used for handling, storage, and processing. Their mechanical properties are used as a measure of material quality. In this study, the mechanical properties of granular biomass obtained from pines (sawdust, shavings, long shavings, and pellets) were determined under a moisture content range of 10–50%. The coefficient of sliding friction µ of four construction materials was determined using a 210-mm-diameter direct shear tester (Jenike’s shear box). To measure the shear resistance of the biomass materials (represented as torque T), a prototype vane tester was constructed. The characteristics of shear resistance with respect to time T(t) were determined for material samples under normal pressure p ranging from 5 to 30 kPa and a vane rotation rate of 3 rpm. Measurements were performed for five geometries of the rotor, reflecting typical deformation conditions encountered in the processing of granular biomass. The coefficient of sliding friction was found to be affected by the type of material, moisture content, and normal compressive pressure. Depending on the biomass material, the highest µ, which ranged from 0.50 to 0.62, was obtained for black steel, whereas the lowest µ, which ranged from 0.27 to 0.52, was obtained for aluminum. The lowest coefficient of sliding friction was observed for dry materials and high normal pressure. The torque T was observed to be affected by the rotor shape, material, normal pressure, and moisture content. The parameters presented provide information useful for the design of transport equipment and processing of granular wood biomass.

Effect of Sample Size on TDA Shear Strength Parameters in Direct Shear Tests

Tire-derived aggregate (TDA), a relatively new construction material, has been gaining acceptance as a backfill material for embankments, trenches, and earth-retaining structures because of its lightweight and excellent geotechnical properties. Type A TDA has a basic geometric shape, with particles approximately 12 to 100 mm in size. As a result of the simplicity and accuracy of the direct shear test, most laboratories choose this test in preference to more complex tests. However, TDA requires large-scale direct shear apparatus because of the consistently large size of its particles, and few facilities own this type of apparatus. Depending on the shear box dimensions, the aspect ratio of the particle size to the box dimensions may lead to variations in the shear strength results of the sample being evaluated. This research focuses on studying the effect of TDA sample size on the shear strength results of direct shear tests by using five different shear box sizes. The findings show that the angle of internal friction increases slightly as the dimensions of the shear box decrease. It was found that the maximum variation in the angle of internal friction and the cohesion results of the different shear boxes was only 1.9° and 2.4 kPa, respectively. These differences should be taken into consideration when TDA shear test results are used in the geotechnical design. It is recommended that a shear box with an aspect ratio (W/Dmax) greater than or equal to 4 should be used when evaluating the shear strength parameters of TDA.