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What is the difference between Safe Bearing Capacity and Gross Bearing Capacity?
Which type of foundation is best for black cotton soil?
Depending on the structural needs one can choose shallow, deep as well as mat foundation. The thing that matters is which type of structure is going to be built. Thank you!
Depending on the structural needs one can choose shallow, deep as well as mat foundation. The thing that matters is which type of structure is going to be built.
Thank you!
See lessexplain briefly about pile foundation and in which type of soil it can be used?
Pile foundations are habitually used for large structures and in certain situations where the soil at shallow depth is unsuitable to withstand excessive settlement & resist uplift. Thank You.
Pile foundations are habitually used for large structures and in certain situations where the soil at shallow depth is unsuitable to withstand excessive settlement & resist uplift.
Thank You.
See lessWhat are the factor affecting in selection of foundation ?
Factors affecting the selection of foundation: Factors affecting the selection of foundation based on politics to basic criteria: Based on soil condition Based on loads from the building 1. based on soil condition: The shallow foundations are most preferred Foundation whenever the soil close to theRead more
Factors affecting the selection of foundation based on politics to basic criteria:
1. based on soil condition:
2. based on loads from the building:
Thank you.
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The floor plan designed by architect for flat area but my site has steep slope what should I do and structural drawings doesn’t shows details clear!
There are two ways to set out foundation on a steep slope :- 1. Cut and fill refers to the process of leveling out the ground for the foundation by adding soil, removing it, or both. Soil may be brought in to fill the plot and make it level, or it can be dug (cut) from the slope and either trucked oRead more
There are two ways to set out foundation on a steep slope :-
1. Cut and fill refers to the process of leveling out the ground for the foundation by adding soil, removing it, or both. Soil may be brought in to fill the plot and make it level, or it can be dug (cut) from the slope and either trucked out or used to shore up retaining walls for the home. Depending on the grade, soil conditions, and other factors, cutting and filling can make construction multiple time more expensive than that for a home on a flat site.
2. Using stilts is an alternative to cutting into the slope that involves using a crane to lift the home onto supporting wood or steel columns. This can be a much more cost-effective method than cut and fill and can also open up the realm of possibilities for home replacement such as building out water over trees or water.
See lessWhat are the bearing capacity values of different types of soils such as clay, sand, gravel, rocks etc.?
Follwoing are the values of safe bearing capacity as per IS:1904–1978 - Rocks - a) hard sound rock - 330 t/m2 or 3240 KN/m2 b) leminated rock - 165 t/m2 or 1620 KN/m2 c) residual deposit of shattered and broken rocks- 90 t/m2 or 880 KN/m2 d) soft rock - 45 t/m2 or 440 KN/m2 Non Cohesive Soil (sandRead more
Follwoing are the values of safe bearing capacity as per IS:1904–1978 –
Rocks –
a) hard sound rock – 330 t/m2 or 3240 KN/m2
b) leminated rock – 165 t/m2 or 1620 KN/m2
c) residual deposit of shattered and broken rocks- 90 t/m2 or 880 KN/m2
d) soft rock – 45 t/m2 or 440 KN/m2
Non Cohesive Soil (sand & gravel ) –
a) compact gravel, sand and gravel – 45 t/m2 or 440 KN/m2
b) compact and dry coarse sand – 45 t/m2 or 440 KN/m2
c) compact and dry medium sand – 25 t/m2 or 245 KN/m2
d) find sand – 15 t/m2 or 150 KN/m2
e) loose gavel or sand – 25 t/m2 or 245 KN/m2
f) loose and dry fine sand – 10 t/m2 or 100 KN/m2
Cohesive soil –
a) hard or stiff clay, soft shale – 45 t/m2 or 440 KN/m2
b) medium clay – 25 t/m2 or 245 KN/m2
c) moist clay and sand clay mixture – 15 t/m2 or 150 KN/m2
d) soft clay – 10 t/m2 or 100 KN/m2
e) very soft clay – 5 t/m2 or 50 KN/m2
f) black cotton soil , peat – by soil investigation
This is bit difficult to state like this. Generally, in fields, we deal with layered soil systems where in you need to work out settlement of each layer and then compare the same to allowable settlement of the subject structure. The allowable settlement for each structure in different and hence the criterion changes all the time.
More than shear criteria, the settlement criteria generally governs the safe bearing capacity of a soil. So, it is difficult to standardize the bearing capacity values in case of soils. May be, in the case of rock, you can standardize the values as the rock does not settle more than 3–4 mm.
See lessWhich type of foundation is used in sea link project bridge?
Most commonly, they use reinforced pile. For e.g., Bandra Worli sea link. The foundations for the BWSL's cable-stayed bridges consist of 120 reinforced concrete piles of 2,000 mm (6.6 ft) diameter. Those for the viaducts consist of 484 piles of 1,500 mm (4.9 ft). These 604 piles were driven betweenRead more
Most commonly, they use reinforced pile.
For e.g., Bandra Worli sea link. The foundations for the BWSL’s cable-stayed bridges consist of 120 reinforced concrete piles of 2,000 mm (6.6 ft) diameter. Those for the viaducts consist of 484 piles of 1,500 mm (4.9 ft). These 604 piles were driven between 6m and 34m into the substrata in geotechnical conditions that varied from highly weathered volcanic material to massive high strength rocks.
See lessWhat is the importance of timbering in trenches for foundations?
Timbering is a method of providing temporary support to the side of the trench and is sometimes called planking and strutting. It is a method to prevent trench side soil against the collapse. If the soil is not hard then during deep excavation the sides of the trench collapse. The sides of the trencRead more
Timbering is a method of providing temporary support to the side of the trench and is sometimes called planking and strutting. It is a method to prevent trench side soil against the collapse. If the soil is not hard then during deep excavation the sides of the trench collapse.
The sides of the trench are timbering to prevent collapse.
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Neenu S K
Hi, In gross bearing capacity, the gross load is taken. Loads from the superstructure, self-weight of the foundation, and overburden pressure are the gross loads. Gross bearing capacity value is not taken in design as it is very high. Safe bearing capacity is the bearing capacity value that neglectsRead more
Hi,
In gross bearing capacity, the gross load is taken. Loads from the superstructure, self-weight of the foundation, and overburden pressure are the gross loads. Gross bearing capacity value is not taken in design as it is very high.
Safe bearing capacity is the bearing capacity value that neglects the overburden pressure and stress due to the footing weight. It is obtained by considering the factor of safety, i.e. net load is taken into consideration. More detailed explanation is given below.
GROSS BEARING CAPACITY OF SOIL (qu)
NET ULTIMATE BEARING CAPACITY OF SOIL (qnu)
SAFE BEARING CAPACITY OF SOIL
- Safe Bearing capacity of soil is obtained after applying the factor of safety.
- It is divided into two:
- Safe Net Bearing Capacity
- Safe Gross Bearing Capacity
- Safe Net Bearing Capacity is defined as the net soil pressure that can be safely applied to the soil considering shear failure alone. It is obtained as qns = Net Ultimate Bearing Capacity (qnu)/Factor of Safety, i.e. qns = qnu/FS
- Safe Gross Bearing Capacity or Safe bearing Capacity is defined as the maximum gross pressure that soil can carry without shear failure. It is given by safe gross bearing capacity qs = qns + γDf
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