1
Q
- 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.
-This means that the development objectives and protect vision are already set in place.
A
Conceptual Design
2
Q
- balances human needs (rather than human wants) with the carrying capacity of the natural and cultural environments. It minimizes environmental impacts, and it minimizes importation of goods and energy as well as the generation of waste.
A
Sustainable design
3
Q
These general precepts give rise to a more explicit set of principles for physical planning at the site scale.
Responsiveness to site and contextual conditions demands consideration of a diverse set of physical attributes and regulatory constraints.
A
Context-Sensitive Design
4
Q
- Spatial variation in elevation produces slopes that have both a gradient and an orientation.
A
Site Topography
5
Q
A retaining wall is a structure built for the purpose of holding back, or retaining or providing one-side lateral confinement of soil or other loose materials.
A
Retaining Wall
6
Q
- 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.
- It is usually so massive that it is unreinforced.
- Tensile stresses calculated by the working
-stress method are usually kept below 1.6 𝑓 ′ 𝑐.
A
Gravity Retaining Wall
7
Q
- 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.
- Semi-gravity walls are used for approximately the same range of heights as the gravity walls and usually have some light reinforcement.
A
Semi-gravity Retaining Walls
8
Q
- 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.
A
Cantilever Retaining Walls
9
Q
- retaining walls with cross walls are behind the stem (i.e., inside the soil) and not visible.
- crosswalls are used when the bending moment at the junction of the stem and footing become so large.
- Used in heights greater than 20-25ft.
A
Counterfort Walls
10
Q
- retaining walls with visible cross walls (i.e., on the toe side).
- are somewhat more efficient than counterforts because they consist of concrete that is put in compression by the overturning moments, whereas counterforts are concrete members used in a tension situation, and they need to be tied to the wall with stirrups.
A
Buttress Walls
11
Q
- 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.
A
Other Types
12
Q
- are made of wire gabion baskets or cage filled with
rocks. - Gabion baskets are secured together to create the desired length.
- This construction is among the strongest available and used
commercially to stabilize shorelines and riverbanks from erosion.
A
Gabion Walls
13
Q
- are synthetic fabrics
with physical and engineering
properties that are used to
enhance soil properties or to
improve structural performance. - are a subset of
geosynthetics
A
Geotextiles
14
Q
plastic nets or grids used for soil reinforcement.
A
Geogrids
15
Q
impervious rubber or plastic sheets used for water or vapor barriers.
A
Geomembranes
16
Q
a combination of a fabric, grid, or membrane.
A
Geocomposites
17
Q
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.
A
Geogrid
18
Q
- 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.
A
HYDROLOGICAL STUDY
19
Q
- Site planning requires an understanding of soils and how they affect hydrology, construction, erosion control, and plant growth.
- Soil affects the design of storm water management facilities.
- Soil engineering properties can greatly affect grading activities, depending on physical parameters such as texture, gradation, and water content.
- Soil also serves as a foundation material, providing support for buildings and other structures.
A
Soil Investigation
20
Q
- excavation for utilities, cut and fill, grading, soil protection, landscaping.
- where retaining walls are necessary, their design will be based on the
engineering properties of the soil and on the presence or absence of additional
groundwater or pore water pressures. - fill operations, including the method of soil placement and the type of
compaction equipment, are specified according to the soil types to be handled. - soil conditions are also evaluated in determining the need for bracing or
shoring of temporary excavations.
A
Earthworks
21
Q
- the weight of building or structure is supported by the soil beneath.
- the design of a footing depends on the applied load and the nature of the underlying soil.
- type of foundation (shallow or deep) are determined by the soil properties.
A
Footings and Foundations
22
Q
- 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).
- sandy: non-cohesive soils tend to be more erodible, more permeable, and easier to drain.
- clayey: soils tend to be more erosion resistant, less permeable, and more difficult to drain.
- satisfied soils: that are composed of layers of both coarse-and fine grained soils may present complex conditions that need to be evaluated in site design.
A
Drainage Requirements
23
Q
- by generally identifying the portions of a site that are suitable or unsuitable for development, the planner can prepare a conceptual site plan.
A
Land Use Feasibility
24
Q
- geotechnical explorations are conducted to identify subsurface conditions and to gather samples for laboratory testing when the structural designer needs data.
A
Site Specific Investigations
25
- 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.
Critical Conditions
26
- 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.
Critical Conditions
27
- from the geotechnical or engineering viewpoint, soil may be defined as an accumulation of solid particles generated from the physical and chemical weathering of parent rock. - soil, therefore, contains three phases: solids, water, and air.
Soil Phases
28
- these properties can include particle size, shape, and mineralogy, along with structure, texture, color, organic matter content, pH, and others.
- physical properties such as density, moisture content, and specific gravity provide useful information to geotechnical experts and reveal how the soil will behave or perform as a construction material.
Physical Properties
29
- first developed to describe soils for agricultural purposes.
- textural designations are based on three major particle size groups: sand, stilt, and clay.
USDA Textural Classification System
30
- the USCS distinguishes soils based on their engineering performance as a construction material, and it considers texture, gradation, plasticity, and organic matter content.
USCS (ASTM D-2487)
31
- classification systems generally describe soil particles as cobble, gravel, sand, stilt, and clay, based on size.
Grain Size
32
- bearing capacity is defined as what a soil is able to support per unit area.
- if the bearing capacity of an existing soil cannot support the proposed load or structure, the soil must be moved and replaced with a suitable material or other engineering measures must be taken.
Bearing Capacity
33
- shear strength determines the stability of a soil and its ability to resist failure under loading.
- shear strength is the result of internal friction and cohesion.
- internal friction is the resistance to sliding between soil particles, and cohesion is the mutual attraction between particles due to moisture content and molecular forces.
Shear Strength
34
- 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.
- damage to structures and roads due to frost action is caused by the movement of soil as it freezes and the loss bearing capacity as it thaws.
Frost Penetration
EXAM
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