PPT 6

Question 1

_______ is the process of adapting the program to the
unique features of the site.
*It contains proposed plans that are spatially organized on the site.

Answer 1

Conceptual design

Question 2

Sustainable, context-responsive site
planning has three fundamental
percepts:

Answer 2

• Design with nature
• Design with culture
• Design places for people

Question 3

Planning for Site Utilities

From site inventory:

Answer 3

1. Site Topography
2. Hydrology Study
3. Soil Investigation

Question 4

Spatial variation in elevation
produces slopes that have both a
gradient and an orientation.

Answer 4

SITE TOPOGRAPHY

Question 5

• Types of Soil Protection

Answer 5

o Retaining Walls
o Gabions
o Geotextile

Question 6

retaining wall

Answer 6

A _______ is a structure built for the purpose of holding back, or
retaining or providing one-side lateral confinement of soil or other
loose materials.

Question 7

Types of Retaining Walls

Answer 7

Gravity Retaining wall
Semi-gravity Retaining Walls
Cantilever Retaining Walls
Counterfort Walls
Buttress Walls
Other Types

Question 8

used for walls of up to about 10-12ft in height.
It is usually constructed with plain concrete
and depends completely on its own weight for
stability against sliding and overturning.

Answer 8

Gravity Retaining wall

Question 9

fall between the gravity and cantilever types.
they depend on their own weights plus the
weight of some soil behind the wall to provide
stability.

Answer 9

Semi-gravity Retaining Walls

Question 10

• the most common type of retaining wall.
• generally used for heights from about 10-25ft.
• stem: the vertical wall
• toe: the outside part of the footing that is
  pressed down into the soil.
• heel: the part that tends to be lifted.

Answer 10

Cantilever Retaining Walls

Question 11

retaining walls with cross walls are behind the
stem (i.e., inside the soil) and not visible.

Answer 11

Counterfort Walls

Question 12

retaining walls with visible cross walls (i.e., on the toe side).

Answer 12

Buttress Walls

Question 13

commonly placed at a property boundary or next to an existing building.
- abutments may very well have wing wall extensions on the sides to retain the
soil in the approach area.
- in addition to other loads, abutments will have to support the end reaction
from the bridge.

Answer 13

Other Types

Question 14

______ are made of wire gabion baskets or cage filled with rocks.
This construction is among the strongest available and used
commercially to stabilize shorelines and riverbanks from erosion.

Answer 14

Gabion walls

Question 15

__________ are synthetic fabrics
with physical and engineering
properties that are used to
enhance soil properties or to
improve structural performance.

Answer 15

Geotextiles

Question 16

plastic nets or grids
used for soil reinforcement.

Answer 16

geogrids

Question 17

impervious
rubber or plastic sheets used for water
or vapor barriers.

Answer 17

geomembranes

Question 18

a combination
of a fabric, grid, or membrane.

Answer 18

geocomposites

Question 19

Geotextiles
Applications of Geotextiles

Answer 19

1. Separation – geotextiles will prevent two soil layers
   of different particle sizes from mixing with each
   other, as is illustrated the image below.
2. Drainage – efficiently collect superfluous water
   from structures, such as rainwater or surplus water,
   from the soil and discharge it.
3. Filtration – ideal interface for reverse filtration in
   the soil adjacent to the geotextile. The complex
   needle-punched structure of the geotextile
   enables the retention of fine particles without
   reducing the permeability of the drain.
4. Reinforcement – heavy geotextiles can be used to
   reinforce earth structures by means of fill materials.
   Its high soil fabric friction coefficient and high
   tensile strength is an ideal reinforcement solution.
5. Protection – geotextiles are an ideal protection
   from erosion. A layer of geotextiles can be placed
   to prevent leaching of fine material. They can be
   used for rock beaching or as mattress structures.
   They can even easily be placed under water.

Question 20

________ is a geosynthetic material, made of polymers, that is used to
reinforce soil behind retaining walls. Installed in horizontal layers
between wall courses and extending into the soil behind a wall,
geogrid stabilizes the soil and so increases a wall system’s mass and
stability.

Answer 20

Geogrid

Question 21

Understanding the potential impact of floodwater on a site is crucial
to any developer looking to invest in a building scheme or any
planner, engineer or architect acting as an adviser to such
development.

Answer 21

HYDROLOGICAL STUDY

Question 22

HYDROLOGICAL STUDY

Answer 22

a. Analysis of rainfall – runoff

• hydrological analysis based on
  rainfall data in the locality.
  b. Delineate Channels and
  Waterways
• delineate catchment and
  identify critical waterways.
  c. Evaluate the capacity of
  existing drainage
• evaluate capacity of road side
  drainage to receive flow.
• proposed size of drainage.
  d. Recommend Flood Control
  System
• drainage mains (layout and sizes)
• detention pond or lagoon
• recommend finish grade
  elevations.

Question 23

Site planning requires an
understanding of soils and how
they affect hydrology,
construction, erosion control,
and plant growth.

Answer 23

SOIL INVESTIGATION

Question 24

Implications of soils for Site Construction

Answer 24

a. Earthworks

• excavation for utilities, cut and fill, grading, soil protection, landscaping.
  b. Footings and Foundations
• the weight of building or structure
  is supported by the soil beneath.
  c. Drainage Requirements
• the relationship between water
  and soil needs to be understood for the
  management of site drainage to be
  successful (including both surface and
  subsurface water).

Question 25

Geotechnical Exploration and Soil
Investigation

Answer 25

a. Land Use Feasibility

• by generally identifying the
  portions of a site that are suitable or
  unsuitable for development, the
  planner can prepare a conceptual site
  plan.

b. Site Specific Investigations
- geotechnical explorations are
conducted to identify subsurface
conditions and to gather samples for
laboratory testing when the structural
designer needs data.

c. Critical Conditions

• critical conditions may include
  features unique to a particular region,
  such as acid soils, limestone sinkholes,
  perched groundwater tables, peat
  deposits, or organic soil deposits.

Question 26

Soil Characteristics

Answer 26

a. Soil Phases

• from the geotechnical or
  engineering viewpoint, soil may be defined
  as an accumulation of solid particles
  b. Physical Properties
• these properties can include particle

size, shape, and mineralogy, along with
structure, texture, color, organic matter
content, pH, and others.

Question 27

Soil Classification

Answer 27

a. USDA Textural Classification
System

• first developed to describe soils
  for agricultural purposes.
• textural designations are based
  on three major particle size groups:
  sand, stilt, and clay.
  b. USCS (ASTM D-2487)
• the USCS distinguishes soils based
  on their engineering performance as a
  construction material, and it considers
  texture, gradation, plasticity, and
  organic matter content.
  c. Grain Size
• classification systems
  generally describe soil particles as
  cobble, gravel, sand, stilt, and clay,
  based on size.

Question 28

Engineering Properties of Soils

Answer 28

a. Bearing Capacity

• bearing capacity is defined as what a soil is able to support per unit area.

b. Shear Strength

• shear strength determines the stability of a soil and its ability to resist failure
  under loading

c. Frost Penetration

• in northern climates, silty soils and soils with a wide, fairly evenly distributed
  range of particle sizes, referred to as well-graded soils, are subject to frost action.

d. Shrinkage and Swell

• clay soils and soils containing clayey fines tend to shrink as they dry and
  expand as moisture content increases.