The following table gives the variation of the field standard penetration number (№60) in a sand deposit: Depth (m) N60 1.5 6 3.0 12 4.5 15 6.0 20 7.5 9.0 18 26 The groundwater table is located at a depth of 12 m. The dry unit weight of sand from 0 to a depth of 12 m is 17.6 kN/m³. Assume the mean grain size (D50) of the sand deposit to be about 0.8 mm. Estimate the variation of the relative density with depth for sand. Use the equation Dr (%) = = N60 (0.23+0.06/D50) 1.7 1 9 σo/Pa 0.5 (100) (Enter your answers to three significant figures.) Depth (m) N60 Dr. (%) 1.5 6 3.0 12 4.5 15 6.0 20 7.5 18 9.0 26

2- Subsurface geotechnical investigations carried out in a deposit of sand provided the field standard penetration numbers N60 as given in the table below. During the geotechnical investigations, it is also observed that underground water table is encountered at a depth of 2.0 m below the ground surface. Laboratory tests have shown that physical properties of deposit of sand are as: Dry unit weight = 17.6 kN/m³ and saturated unit weight = 19.6 kN/m³. Determine, for an earthquake magnitude of 8.25, if liquefaction will occur at the site. Assume that maximum peak ground acceleration at the site is: amax = 0.25g. (6 points) DEPTH (M) N60 (BLOWS/30CM) 3 5 6 7 9 11 12 14 18 21 Note: the gravitational acceleration could be taken as 9.81 m/s².

Question Attached

Problem attached

Determine the relative density at each depth using attached equation. Assume moderately compressible sand and hence Qc = 1.

Determine the relative density at each depth using attached equation. Assume moderately compressible sand and hence Qc = 1.

21 The results of a constant head permeability test for a fine sand are as follows: Diameter of the sample = 37 cm Length of sample = 92 cm Constant head difference = 78 cm Time of collection = 337 secs Weight of water collected = 375 grams Find the seepage velocity in cm/min. if the void ratio is 0.6. Round off to four decimal places.

A cone penetration test result of a deposit of normally consolidated dry sand are given below. Estimate the drained friction angle of the sand using Kulhawy and Mayne's equation. The unit weight of the sand is 100 pcf. Depth ft 5.0 10.0 15.0 20.0 25.0 30.0 45 38 42 40 Tip resistance of cone, qc psi 300 600 800 1200 1400 1800

Refer to Problem 3.5. Using Eq. (3.28), determine the averagerelative density of the sand. Assume it is a fine sand.Use Eq. (3.13) to obtain (N1)60.

In a deposit of normally consolidated dry sand a cone penetration test was conducted. Following are the result: Depth(m) Point resistance of cone, qc (MN/m²) 1.5 2.06 3.0 4.23 4.5 6.01 6.0 8.18 7.5 9.97 9.0 12.42 Assuming the dry unit weight of sand to be 16kN/m³, estimale the average peak friction angle, ф’, fo the sand. Use ф’=tan ¯1((0.38+0.27log(qc/ σ’o))