A direct shear test is conducted on a large specimen of dry sand (square cross section...

A direct shear test is conducted on a large specimen of dry sand (square cross section with following dimensions: 7.5 cm x 7.5 cm x 3.0 cm [height], Mass = 271.0 g) with a normal stress of 500 kPa. Failure occurred when the horizontal force was 1.96 kN. For the same sand, tests were also conducted to determine the specific gravity and the maximum and minimum void ratios. These tests yielded the following results: Gs= 2.65, emax=0.80, emin = 0.45. a) Calculate the relative density of the sand specimen b) Determine the friction angle of the soil. c) A triaxial specimen (H= 8.0 cm, D = 3.8 cm, Dr~45%) is prepared using the same sand. The test is performed on a saturated specimen with a chamber pressure of 500 kPa and an initial value of the pore pressure u of 100 kPa. Assuming that the results of the direct shear test can be used to predict those of the triaxial test, at what value of the total axial stress does the triaxial specimen fail?

Expert Solution

Ally Wells answered 1 year ago

Direct shear tests were performed on a dry, sandy soil. The size of the specimen was...

Direct shear tests were performed on a dry, sandy soil. The size of the specimen was 50 mm x 50 mm x 20 mm (LxWxH). Test results are given in the following table. Find the shear stress parameters. Estimate the major and minor principal stresses, and the orientation of the principal stresses at failure for Test 2 Test No. Normal Force (N) Shear force at failure (N) 1 90 55 2 135 80 3 315 190

Generally, how reliable are Shear Box Tests for dry sand? What are common factors in the...

Generally, how reliable are Shear Box Tests for dry sand? What are common factors in the testing procedure or design which influence reliability? How can one tell if results are reliable? In general terms, as normal force is increased on a sample, what can be expected?

A sand specimen is isotropically consolidated in a triaxial test apparatus to 420 kPa and then...

A sand specimen is isotropically consolidated in a triaxial test apparatus to 420 kPa and then sheared with the drainage valves open (i.e., an S or CD test). At failure, (σ1 – σ3) is 1046 kPa. Determine the major and minor principal stresses at failure and the effective internal friction angle (assume c' = 0). Plot the Mohr diagram. (Problem originally from Holtz and Kovacs, 11-10) Another specimen of the same sand as in Problem 1 (i.e., same f' and...

A steel alloy specimen having a rectangular cross section of dimensions 19.1 mm × 3.0 mm...

A steel alloy specimen having a rectangular cross section of dimensions 19.1 mm × 3.0 mm (0.7520 in. × 0.1181 in.) has the stress-strain behavior shown in the Animated Figure 6.22. If this specimen is subjected to a tensile force of 95120 N (21380 lbf) then (a) Determine the amount of elastic strain induced. (b) Determine the amount of plastic strain induced. (c) If its original length is 590 mm, what will be its final length after this force is...

Circular bars subjected to torsion experience Pure Shear over the cross section. Then, why a classroom...

Circular bars subjected to torsion experience Pure Shear over the cross section. Then, why a classroom chalk subjected torsion experience brittle failure by tension cracking at 45° to the circular cross section? Do some research and explain how shafts made of ductile materials fail when subjected to torsion. Compare and contrast both the brittle failure in chalk and ductile failure in shaft. Explain your answer using the plotted graphs.

Determine the limiting values of the width a of a waveguide of square cross section which...

Determine the limiting values of the width a of a waveguide of square cross section which will transmit a wave of length lambda in the TE10 mode but not in the TE11 or TM11 modes.

Determine the location of the shear centre of the C-shaped rolled-steel beam cross-section C150x19.3 with respect...

Determine the location of the shear centre of the C-shaped rolled-steel beam cross-section C150x19.3 with respect to the centre of the web. Indicate whether it is to the left or right of the centre of the web. Assume the section to be thin walled and neglect the rounding of corners.

An aluminum rod with a square cross section is 1.2 m long and 5.0 mm on...

An aluminum rod with a square cross section is 1.2 m long and 5.0 mm on edge. (a) What is the resistance between its ends? (b) What must be the diameter of a cylindrical copper rod of length 1.2 m if its resistance is to be the same as that of the aluminum rod? The resistivity of aluminum is 2.75 × 10-8 Ω·m and the resistivity of copper is 1.69 × 10-8 Ω·m.

The cantilever is affixed to the free end of a square cross-section piezoelectric (PZT) block, which...

The cantilever is affixed to the free end of a square cross-section piezoelectric (PZT) block, which is fixed at the other end. Draw the schematic of the lumped-parameter model of the cantilever-PZT system, obtain the mathematical model of this mechanical system, and derive the lumped mass and stiffness of the PZT knowing that la = 0.01 m (length of PZT block), a = 0.005 m (side length of PZT cross-section), EPZT = 55 GPa (Young’s modulus), ?PZT = 7500 kg/m3...

A polymer rod is tested to determine its viscoelastic response. The rod’s cross-section is square with...

A polymer rod is tested to determine its viscoelastic response. The rod’s cross-section is square with the side of 5mm. The rod’s length before loading is 500mm. A tensile force of 500N is applied to the rod and the rod’s length under load was measured as a function of time. Instantly after applying the load, the rod is stretched to 508mm. After 24 and 48 hour under load, the rod’s length was measured as 550mm and 570mm, respectively. The load...

Question