SITE INVESTIGATION

Question 1

simply is the process of the
collection of information, the appraisal of data,
assessment, and reporting without which the
hazards in the ground beneath the site cannot be
known.

Answer 1

site investigation

Question 2

carried out in order to
enable a geotechnical and geoenvironmental
assessment of the ground conditions and analysis
of the engineering and environmental
considerations related to the proposed
development.

Answer 2

Site investigation

Question 3

The reason for a site investigation

Answer 3

✓ The composition of soil layers and bedrock

✓ Groundwater conditions

✓ Durability, compressibility, and strength of soil, rocks, soil strata

✓ Chemical composition of groundwater on site

✓ Composition of foundations on nearby site

Question 4

STAGES OF SITE
INVESTIGATION

Answer 4

• Preliminary Site Investigation
• Detailed Site Investigation
• Supplementary Investigation and Construction Control
• Background Information before
  Subsurface Investigation

Question 5

Background Information before
Subsurface Investigation

Answer 5

1.Minimizes Damage
2. Saves on Costs
3. Helps Determine the Construction
Materials
4. Increases the Safety of the Project

Question 6

Are the most commonly conducted geophysical surveys for
engineering investigations.

Answer 6

SEISMIC
METHODS

Question 7

depend upon
velocities of acoustical energy in earth materials.

Answer 7

Seismic methods

Question 8

Any mechanical vibration is initiated by a source and travels to
the location where the vibration is noted.

• The vibration is merely a change in the stress state due to a
  disturbance.
• The vibration emanates in all directions that support
  displacement. It readily passes from one medium
  to another and from solids to liquids or gasses and in reverse.

Answer 8

SEISMICWAVES

Question 9

direction of travel

Answer 9

the ray, ray vector, or ray path.

Question 10

TWO MAJOR
CLASSES OF
SEISMIC
WAVES

Answer 10

1. BODYWAVES
   
   • P-WAVES
   • S-WAVES
2. SURFACEWAVES
   
   • LOVEWAVES
     * RAYLEIGHWAVE

Question 11

These are the
fastest traveling of all seismic
waves and are called
compressional or pressure or
primary wave

Which pass through the volume
of a material.

Answer 11

BODY WAVES

Question 12

Travel through all media that
support seismic waves; air
waves or noise in gasses,
including the atmosphere.

Answer 12

P-WAVES

Question 13

transverse or shear wave

travel slightly slower than
P-waves in solids.

have particle
motion perpendicular to the propagating
direction, like the obvious movement of a
rope as a displacement speeds along its
length.

These transverse waves can only
transit material that has shear strength.

Answer 13

S-WAVES

Question 14

do not exist in liquids and
gasses, as these media have no shear
strength

Answer 14

S-waves

Question 15

Are produced by surface impacts,
explosions, and waveform changes at
boundaries.

travel
slower than body waves.

Answer 15

SURFACE WAVES

Question 16

A type of seismic surface wave in which
particles move with a side-to-side motion
perpendicular to the main propagation of the earthquake. The amplitude of this motion decreases with depth.

cause the rocks they
pass through to change in shape.

Answer 16

LOVE WAVES

Question 17

An undulating wave that travels over the
surface of a solid, especially of the ground
in an earthquake, with a speed independent
of wavelength, the motion of the particles
being in ellipses.

A point in the path moves back, down, forward, and up
repetitively in an ellipse like
ocean waves .

Answer 17

RAYLEIGH WAVE

Question 18

have continued to allow the
production of better seismic equipment.

Answer 18

Digital electronics

Question 19

may be a hammer striking the
ground or an aluminum plate or weighted plank, drop
weights of varying sizes, rifle shot, a harmonic
oscillator, waterborne mechanisms, or explosives. The
energy disturbance for seismic work is most often
called the “shot,

” an archaic term from petroleum

seismic exploration.

Answer 19

seismic source

Question 20

sensor receiving seismic energy

These sensors are either
accelerometers or velocity transducers, and
convert ground movement into a voltage.

Answer 20

GEOPHONES

Question 21

The equipment that records input
geophone voltages in a timed sequence

Answer 21

SEISMOGRAPHS

Question 22

The ratio of the reflected energy to incident energy

Answer 22

reflection
coefficient

Question 23

one may measure
potentials, currents, and electromagnetic fields that occur
naturally or are introduced artificially in the ground.

Answer 23

electrical methods,

Question 24

CLASSIFICATION

OF ELECTRICAL

METHODS

Answer 24

1. self-potential (SP)
2. telluric currents and
   magnetotellurics,
3. resistivity,
4. equipotential and
   mise-à-la-masse,
5. electromagnetic (EM),
6. induced
   polarization (IP)

Question 25

is a passive electrical geophysical method based upon the measurement of spontaneous or natural electrical potential developed in the earth due to: 1)electrochemical interactions between minerals and subsurface fluids; 2) electrokinetic processes resulting from the flow of ionic fluids; or 3) thermoelectric mechanisms from temperature gradients in the subsurface

Answer 25

self-potential (SP) technique

Question 26

Also called Earth Current, natural electric current flowing on and beneath the surface of the Earth and generally following a direction parallel to the Earth’s surface.

Answer 26

TELLURIC CURRENT

Question 27

A measure of the resistance of a given size of a specific material to electrical conduction. may also be referred to as the specific electrical resistance, or volume resistivity.

Answer 27

Resistivity

Question 28

was one of the first electrical methods and was used as far back as 1912 by Schlumberger. As explained elsewhere in this volume, when electric energy is applied to two points at the ground surface, an electric current will flow between them because of their difference in electrical potential.

Answer 28

EQUIPOTENTIAL METHOD

Question 29

Is still used in mining exploration and occasionally in geotechnical applications. uses the conductive mass under investigation as one of the current electrodes.

Answer 29

MISE-A-LA-MASSE

Question 30

MISE-A-LA-MASSE

Answer 30

translated as “excitation of the mass,

Question 31

Use transmitters to create strong time-varying primary magnetic fields that induce electrical currents to flow in conductive rocks. These currents, in turn, create secondary electromagnetic fields that are detected by receiver antennae.

Answer 31

ELECTROMAGNETIC (EM) METHODS

Question 32

Resistivity are two electrical properties measured in near- surface sediments as indirect hydrocarbon indicators. They are usually measured at the same time by inserting two electrodes into the earth surface and passing a current through them.

Answer 32

INDUCED POLARIZATION (IP)