a) In an SPT test, the hammer entered the first 15 cm into a sandy soil with 10 blows. The next 15 cm was obtained with 2 blows and the last 15 cm was obtained with 3 blows, What is SPT value of this soil? Comment about the denseness of the soil. 6. b) Calculate the Rock Quality Designation (RQD) value and comment on the quality of the given rock.

a) In an SPT test, the hammer entered the first 15 cm into a sandy soil with 10 blows. The next 15 cm was obtained with 2 blows and the last 15 cm was obtained with 3 blows, What is SPT value of this soil? Comment about the denseness of the soil. 6. b) Calculate the Rock Quality Designation (RQD) value and comment on the quality of the given rock.

Principles of Geotechnical Engineering (MindTap Course List)

9th Edition

ISBN:9781305970939

Author:Braja M. Das, Khaled Sobhan

Publisher:Braja M. Das, Khaled Sobhan

Chapter17: Subsoil Exploration

Section: Chapter Questions

Problem 17.15P

See similar textbooks

Similar questions

A soil excavation was done until 4m below the surface of the soil. It was identified that the shallow ground water level is 2m below the ground level and the upper is dry. The properties of the soil are: Gs = 2.7, e = 0.50, and ϕ’ = 30degrees. Assuming no seepage. What is the value of the in-situ soil’s unit weight above G.W.T. in kN/m3? What is the maximum neutral stress at the deepest point of excavation in kPa? What is the value of the total stress of soil at the surface of the ground water table in kPa? What is the value of the effective stress at the deepest point of excavation in kPa?
A. Determine shear strength of the soil in the review level (Right answer 46.2 kPa) B. Determine The closed shear strength of the soil in the Review level (Right answer 10 kN/m2)
Question 10 A 50 m run of core drilled horizontally from an underground drift allowed to recover 42 m ofrock core and 38 m of this core was in pieces longer than 100 mm. In the 4 m of recoveredrock core with pieces smaller than 100 mm, 2 meters contained fresh and sharp breaks(fractures).(a) Determine the Rock Quality Designation (RQD) value and the corresponding rock qualitydescription. (b) Describe the limitations of using RQD to evaluate rock quality and make suggestions onhow you can minimize the sources of error.
(b) Describe rock parameters that obtained from the following testing: (i) Seismic Velocity test (ii) Brazilian test (iii) Slake durability test (iv) Schidmt hammer test (v) Triaxial Compression Test (vi) Point load test
Regarding impact resistance, determine what energy is mobilized by rock of 150-mm size falling out of a dump truck 1.5-m to the geotextile, if the geotextile rests on the following: (a) A “soft” soil of unsoaked CBR = 3 (b) A “firm” soil of unsoaked CBR = 9 (c) A “hard” soil of unsoaked CBR = 16
In the excavation of a certain foundation pit, draining water causes upward seepage. The water head difference is 60cm, the length of water flow through the soil is 50cm, the saturated unit weight y=20.5 kN/m². Determine whether the heaving sand happens or not. Give the reason if happens or not
In a site consisting entirely of clays, an electric friction conepenetrometer measures the cone resistance qc at a depth of8.0 m as 0.75 MN/m2. The water table is at 3.0 m below theground level. The unit weights of the clay above and belowthe water table are 16.5 kN/m3 and 19.0 kN/m3, respectively.Estimate the undrained shear strength, preconsolidationpressure, and overconsolidation ratio at this depth.
An embankment consists of clay fill for which c′ = 25 kN/m2 and φ = 27° (from consolidated undrained tests with pore-pressure measurement). The average bulk unit-weight of the fill is 2 Mg/m3. Estimate the shear-strength in kPa of the material on a horizontal plane at a point 20 m below the surface of the embankment, if the pore pressure at this point is 180 kN/m2 as shown by a piezometer.
A shallow square foundation for a column is to be constructed. It must carry a net vertical load of 1000 kN. The soil supporting the foundation is sand. The standard penetration numbers (N60) obtained from field exploration are as follows: FIG. 17.15 The groundwater table is located at a depth of 12 m. The unit weight of soil above the water table is 15.7 kN/m3, and the saturated unit weight of soil below the water table is 18.8 kN/m3. Assume that the depth of the foundation will be 1.5 m and the tolerable settlement is 25 mm. Determine the size of the foundation.
A 1.5 m thick strata of sand has a dry unitweight of 15 kN/m3. A contractor passes a vibratory roller over this strata, whichdensifies it and increases its dry unit weightto 16.5kN/m3. Compute its new thickness. Hint: consider 1 m x 1 m column of soil.
The results of a three consolidated undrained tri-axial test on saturated clay are as follows: Compute the angle of internal friction a. 15.03 degreesb. 12.06 degreesc. 18.40 degreesd. 31.05 degrees
2. How to evaluate the rock properties according to the distribution curves and give at least two coefficients of that.