PROBLEMA 1.1 BRAJA M.DAS ANALISIS GRANULOMETRICO

Summary

In this tutorial, Enrique Zuleta explains a soil mechanics exercise based on a geotechnical engineering textbook. He walks viewers through calculating soil distribution curves using granulometry data, discussing the percentage of fine particles and various sieve sizes. The process includes determining values like D10, D30, and D60, which correspond to the particle sizes at specific percentages of fines. Additionally, the tutorial covers calculating coefficients such as C60 and C30/10, which provide insights into soil characteristics. The video aims to help students and professionals understand soil behavior and prepare for further analysis in geotechnical studies.

Takeaways

• 😀 The video tutorial is presented by Enrique Zuleta, who explains a geotechnical soil mechanics exercise from the book 'Fundamentals of Geotechnical Engineering'.
• 😀 The exercise focuses on the granulometric distribution curve, which involves calculating the mass of soil retained by sieves and determining the percentage of fines that pass through each sieve.
• 😀 The process begins with calculating the total mass of the soil sample, which is 450 grams after summing the individual mass values from the sieves.
• 😀 The next step is calculating the percentage of soil retained by each sieve, using the formula: (Mass retained / Total mass) * 100.
• 😀 For each sieve, the percentage of fines is determined by subtracting the retained mass percentage from the previous sieve's percentage.
• 😀 A table is created to show the percentage of soil retained in each sieve, which is then used to calculate the fines percentages for each sieve.
• 😀 The diameters for 10%, 30%, and 60% fines (D10, D30, D60) are calculated through interpolation using logarithmic scales for diameter and linear scales for percentage of fines.
• 😀 The D10, D30, and D60 values represent the diameters at which 10%, 30%, and 60% of the soil particles are finer than those diameters, respectively.
• 😀 The D10 value is calculated by interpolating between the 100-mesh and 200-mesh sieves, resulting in a diameter of approximately 0.0878 mm.
• 😀 Similarly, D30 and D60 are calculated using interpolation between appropriate sieves, resulting in diameters of 0.1891 mm and 0.409 mm, respectively.
• 😀 The video also explains how to calculate the coefficients of uniformity (Cu) and curvature (Cc) using the formulas Cu = D60 / D10 and Cc = (D30^2) / (D10 * D60).
• 😀 The tutorial concludes by encouraging viewers to like, share, and subscribe for more content on geotechnical topics, including further exercises and curve plotting.

Q & A

What is the main focus of the exercise described in the video?

The main focus of the exercise is the calculation of granulometric distribution curves and various parameters like the percentage of fines, D10, D30, and D60 diameters, and the coefficients Cc and Cu for a soil sample.

What does the term 'granulometric distribution' refer to in soil mechanics?

Granulometric distribution refers to the classification of soil particles based on their size, typically represented by a granulometric curve, which shows the percentage of soil retained on various sieves.

How is the total mass of the soil sample determined in the exercise?

The total mass of the soil sample is calculated by summing up the mass retained on each sieve, with the final total mass being 450 grams in the example.

What is the formula used to calculate the percentage of soil retained on each sieve?

The percentage of soil retained on each sieve is calculated using the formula: (mass retained on sieve / total mass) * 100.

What is the method used to calculate the percentage of fines in the soil sample?

The percentage of fines is calculated by taking the difference between the current percentage of retained soil and the percentage from the previous sieve.

How are the D10, D30, and D60 diameters determined from the granulometric data?

The D10, D30, and D60 diameters are determined by interpolating the diameters corresponding to 10%, 30%, and 60% of fines on the granulometric curve. This interpolation is done using logarithmic scales for the diameters.

Why is logarithmic interpolation used for calculating diameters like D10, D30, and D60?

Logarithmic interpolation is used because the diameters on the granulometric curve are represented on a logarithmic scale, ensuring that the calculations are more accurate and aligned with the distribution of particle sizes.

What is the purpose of calculating the coefficients Cc and Cu in this exercise?

The coefficients Cc (curvature coefficient) and Cu (uniformity coefficient) are used to describe the shape and distribution of the soil particles. These coefficients help in classifying the soil's granulometric characteristics.

How is the coefficient Cu calculated?

The coefficient Cu is calculated by dividing the diameter D60 by D10, i.e., Cu = D60 / D10. This ratio indicates the uniformity of the soil.

What is the formula for calculating the coefficient Cc?

The coefficient Cc is calculated using the formula: Cc = (D30^2) / (D10 * D60), where D30, D10, and D60 are the diameters corresponding to 30%, 10%, and 60% of fines, respectively.