Introduction to Site Investigation
40 Questions
0 Views

Choose a study mode

Play Quiz
Study Flashcards
Spaced Repetition
Chat to lesson

Podcast

Play an AI-generated podcast conversation about this lesson

Questions and Answers

What is the primary purpose of site investigation (SI)?

  • To assess the aesthetic value of the construction site
  • To evaluate the potential environmental impact of the construction
  • To gather information about the stratification and engineering properties of the soils (correct)
  • To determine the availability of construction materials
  • Which of the following is NOT a principal engineering property of interest in site investigation?

  • Permeability
  • Strength
  • Density (correct)
  • Deformation
  • How does site investigation impact the design of foundations?

  • It provides insights into construction techniques.
  • It measures the performance of completed structures.
  • It offers a review of environmental regulations.
  • It informs the suitability and design parameters for the site. (correct)
  • What could potentially lead to engineering failures according to the principles of site investigation?

    <p>Improper site investigation</p> Signup and view all the answers

    What can be discovered through a proper site investigation?

    <p>Presence of sinkhole risks</p> Signup and view all the answers

    Which factor is critical to ensure the success of foundation design based on site investigation?

    <p>Reliability of knowledge obtained from site investigation</p> Signup and view all the answers

    What does the program of site investigation involve?

    <p>An outline for data collection and analysis</p> Signup and view all the answers

    What is a key objective of site investigation?

    <p>To assess the suitability of the site for the proposed construction</p> Signup and view all the answers

    What is the formula to calculate frictional resistance (Fr) in relation to cone resistance (qc)?

    <p>Fr = (frictional resistance)/(cone resistance)</p> Signup and view all the answers

    Which equation describes the relationship between Fr and D50 for an electric cone?

    <p>Fr (%) = 1.45 - 1.36log D50</p> Signup and view all the answers

    What does D50 represent in soil mechanics?

    <p>The size through which 50% of soil will pass</p> Signup and view all the answers

    In the equation Dr = 68[log(qc / pa) - 1], what does pa represent?

    <p>Atmospheric pressure</p> Signup and view all the answers

    What is the purpose of the vane shear test?

    <p>To measure the in situ undrained shear strength of clay soils</p> Signup and view all the answers

    What is the standard rotation rate during the vane shear test?

    <p>0.1 degrees/sec</p> Signup and view all the answers

    What does the Overconsolidation Ratio (OCR) indicate in the context of soil properties?

    <p>How much stress a soil can withstand compared to its past maximum stress</p> Signup and view all the answers

    What does Cu represent in the context of the vane shear test?

    <p>The in situ undrained shear strength of clay soils</p> Signup and view all the answers

    What does a highly compressible sand Qc value indicate?

    <p>Qc = 0.91</p> Signup and view all the answers

    Which of the following statements accurately reflects the relationship between Dr and qc?

    <p>Higher qc leads to a lower Dr</p> Signup and view all the answers

    What factor is represented by K in the formula for calculating shear strength?

    <p>Vane constant</p> Signup and view all the answers

    What is the significance of the maximum torque, T, during the vane shear test?

    <p>It is the torque applied to induce failure in the soil</p> Signup and view all the answers

    Which of the following is NOT a recommended value of Qc for various types of sand?

    <p>Low compressible sand = 1.5</p> Signup and view all the answers

    How does the geometry of the vanes affect the calculation of the vane constant, K?

    <p>Both the height and the diameter of the vanes are important</p> Signup and view all the answers

    For tapered vanes, what is the formula to determine K when the ratio of height to diameter, h/d, equals 2?

    <p>K = 7πd</p> Signup and view all the answers

    What is the primary advantage of using the vane shear test?

    <p>It minimizes soil disturbance during testing</p> Signup and view all the answers

    What equation is used to determine undrained shear strength (Cu)?

    <p>$C_u = \frac{q_c - s_o}{N_k}$</p> Signup and view all the answers

    Which of the following variables can the value of N vary between when determining undrained shear strength?

    <p>11 to 19</p> Signup and view all the answers

    What does the parameter $s_o$ represent in the equation for Cu?

    <p>Total vertical stress</p> Signup and view all the answers

    In the correlation using horizontal effect stress, what is the constant value associated with $q_c$?

    <p>0.1714</p> Signup and view all the answers

    Which equation represents the correlation between $q_c$ and the Drained Friction Angle for sand?

    <p>$f = tan[0.38 + 0.27log(\frac{q_c}{s_o})]$</p> Signup and view all the answers

    What does the variable $N_{60}$ represent in the correlation equation for $q_c$ and $N$?

    <p>Standard penetration test value</p> Signup and view all the answers

    What does the term 'Overconsolidation Ratio (OCR)' generally refer to in foundation engineering?

    <p>The ratio of preconsolidation pressure to current vertical stress</p> Signup and view all the answers

    In the equation for the correlation between $q_c$ and $N$, which parameter is multiplied by $c$ to find $N_{60}$?

    <p>D50</p> Signup and view all the answers

    What is the primary purpose of the Plate Load Test (PLT)?

    <p>To determine the ultimate bearing capacity of soil</p> Signup and view all the answers

    Which of the following tests is not categorized as a laboratory test in foundation engineering?

    <p>Plate Load Test</p> Signup and view all the answers

    In preparing a boring log, which of the following information is essential?

    <p>Boring information including type and depth</p> Signup and view all the answers

    What does the ultimate bearing capacity indicate in a Plate Load Test?

    <p>The maximum load before a sudden increase in settlement occurs</p> Signup and view all the answers

    Which test is specifically used to measure the permeability of soil?

    <p>Permeability test</p> Signup and view all the answers

    Which of the following methods is used to assess soil particle size in the laboratory?

    <p>Sedimentation</p> Signup and view all the answers

    During site investigations, subsurface stratification can be obtained through which of the following?

    <p>Visual observation of soil samples</p> Signup and view all the answers

    What is a key detail that must be recorded regarding groundwater in a boring log?

    <p>Date observed and elevation of water table</p> Signup and view all the answers

    Study Notes

    Introduction to Site Investigation

    • Site Investigation (SI) is crucial for understanding the subsurface conditions prior to construction of structures like buildings and bridges.
    • SI involves gathering data about soil stratification and engineering properties including strength, deformation, and permeability.
    • Proper SI helps identify risks (e.g., sinkholes) and determines the reliability of foundation design.

    Objectives of Site Investigation

    • Obtain knowledge about ground conditions to determine site's suitability for proposed constructions.
    • Essential for estimating design parameters like strength and compressibility.

    Vane Shear Test

    • Used during drilling to measure in situ undrained shear strength (Cu) of clay soils.
    • Torque applied at a standard rate rotates vanes, inducing soil failure; maximum torque (T) is measured.
    • The equation relates Cu to T and the vane constant (K), essential for assessing soil strength.

    Correlation of Soil Properties

    • Relationships exist between various soil factors such as relative density (Dr), compressibility, and bearing capacity.
    • Dr can be correlated with cone resistance (qc) and atmospheric pressure to assess effective stress.
    • Specific formulas exist to determine relationships between undrained shear strength (Cu), preconsolidation pressure, and overconsolidation ratio (OCR) for clays.

    Testing Methods

    • In-Situ Tests: Includes Plate Load Test (PLT) that assesses soil's ultimate bearing capacity through loading and observing settlement.
    • Laboratory Tests: Analyze physical properties (moisture content, specific gravity), particle size, and perform various strength tests (direct shear, unconfined compression, triaxial).

    Reporting Procedures

    • Sequence of site investigation includes planning, implementation, and reporting.
    • Preparation of boring logs details information on drilling company, type and location of borings, subsurface stratification, groundwater elevation, and in-situ test results.

    Boring Logs

    • Essential for documenting subsurface conditions and includes:
      • Initial drilling company information
      • Subsurface stratification observations
      • In-situ test data, such as Standard Penetration Test (SPT) results
      • Soil sample collection details, including type and depth of samples.

    Practical Application

    • Example site investigations, like for bridge proposals, involve assessing subsoil and groundwater conditions through collected boring data.

    Studying That Suits You

    Use AI to generate personalized quizzes and flashcards to suit your learning preferences.

    Quiz Team

    Description

    This quiz covers the essentials of Site Investigation (SI), including its objectives and methods like the Vane Shear Test. Understanding SI is crucial for evaluating subsurface conditions and ensuring safe construction practices. Test your knowledge on soil properties and their importance in foundation design.

    More Like This

    Geotechnical Investigations Overview
    5 questions
    Site Investigation and Soil Analysis
    28 questions
    Use Quizgecko on...
    Browser
    Browser