Category: Civil Projects

In this article we will discuss about Rankine Earth Pressure for passive case. Figure 1 shows the Mohr’s circle in which point B indicates the vertical stress and point E represents the passive pressure. The wall carries a uniform surcharge q. The circle is tangent to the failure envelope. For this case the relation between Pa and  is given by:   ———-(1) Where,  Pressure Distribution of passive case in cohesive soil Figure 2 given below shows the pressure distribution behind a wall retaining a cohesive backfill. The total resultant passive…

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In this article we will discuss about Rankine Earth Pressure for active case. Figure 1 shows the Mohr’s circle in which point B indicates the vertical stress and point E represents the active pressure. The circle is tangent to the failure envelope. For this case the relation between Pa and  is given by: ———-(1)  ———-(2)   Where, In the above equation (2) where z = 0 The negative sign indicates that the pressure is negative and tensile, As a result there would be gap between backfill and wall. The tensile…

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What are Effect of Sloping Surcharge in Passive Case? In previous article we had already posted Effect of Sloping Surcharge in Active Case, now in this article we are dealing with Effect of Sloping Surcharge in Passive Case. The Mohr Circle for the passive case of a retaining wall carrying a sloping backfill is shown in Fig.1. Consider an element subjected to a stress in the  in the vertical direction and  in the direction parallel to the backfill. As these stresses in one plane are parallel to the direction of another…

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What are the Effect of Sloping Surcharge in Active Case? in this article we will discuss about Effect of Sloping Surcharge in Active Case. A wall carrying a sloping backfill is shown in Fig.1. Consider an element subjected to a stress  in the vertical direction and  in the direction parallel to the backfill. As these stresses in one plane are parallel to the direction of another plane, these stresses are conjugate stresses and the planes are the conjugate planes. The equivalent vertical stress acting parallel to the surface of backfill is…

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What is Active Earth Pressure for Partially submerged Sand with Surcharge? In Figure 1 active earth pressure for partially submerged sand and surcharge is shown. The height of the wall is Z and the position of the water table is at a depth of Z1 and the surcharge acting at the top of horizontal surface of the wall is q. The height of the wall below water table is Z2. The unit weight of the sand above water table is  and that below water table is . CASE 1 | Active Earth…

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In this article we will discuss about mohr circle for passive earth pressure, figure 1 below shows the state of stresses on the base and the side of the prism CA at depth Z in a Mohr circle. The vertical stress is the principal stress. OP and OQ are the two Mohr envelopes satisfying the Coulomb’s equation of shear strength. Initially the stresses  and are the major and minor principal stress. The points A and B in mohr circle for passive earth pressure diagram respectively denote these stresses at rest condition.…

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IN this article we will discuss about Mohr Circle for active earth pressure. Figure 1 below shows the state of stresses on the base and the side of the prism CA at depth z in a Mohr circle. The vertical stress  is the principal stress. OP and OQ are the two Mohr envelopes satisfying the Coulomb’s equation of shear strength. Initially the stresses and are the major and minor principal stresses. The points A and B in the Mohr Circle for active earth pressure diagram respectively denote these stresses at…

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W. J. Rankine in 1857 published his theory of lateral earth pressure from a different approach. Rankine’s earth pressure theories provide the magnitude, direction, and point of application of active and passive earth pressures acting on a retaining wall. These theories are known as classical earth pressure theories. Rankine’s made the following assumptions while deriving his earth pressure theory. The assumptions are: The soil mass is homogeneous and semi-infinite. The back of the retaining wall is vertical. The back of the Wall is smooth. The wall movement is sufficient so…

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When a soil mass gets deposited naturally or artificially, the coefficient of earth pressure attains a value known as coefficient of earth pressure at rest (K0) which is intermediate between coefficient of active earth pressure (Ka) and coefficient of passive earth pressure (Kp) values. In this case the horizontal stress is given by, —————————–(1) Where,  = Vertical Stress at depth ‘z’ = Unit weight of soil z = Depth below ground surface The value of K0 depends upon the relative density of sand, and the process by which the process…

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The amount of movement is called yield. The relation between yield and magnitude of earth pressure is illustrated in Fig.1. As the earth pressure largely depends upon the flexibility of the wall, the earth pressure problem is a case of soil structure interaction. The soil in the region beyond the active and passive state of failure will be in plastic state while the soil in the region within the active and passive state will be in the elastic state. Such failure of a soil mass is called the state of plastic…

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