Two … US Concrete Wall Footing - Design Example Problem Statement. f'c = 3000 psi fy = 60 ksi o Development of Structural Design Equations. We can find a value for $q_u$, the soil pressure at the factored load level, by dividing our total applied load by the footing area. Soil: equivalent fluid pressure is 45 psf/ft (7.0 kN/m²/m) (excluding soil load factors), 10 ft (3.05 m) backfill height. Boundary wall design with spreadsheet file. Reinforced Concrete SK 3/3 Section through slab showing stress due to moment. Retaining walls are utilized in the formation of basement under ground level, wing walls of bridge and to preserve slopes in hilly … The CivilWeb Concrete Shear Wall Design Spreadsheet is a powerful spreadsheet for the design of shear walls in … This Practical Design Manual intends to outline practice of detailed design and detailings of reinforced concrete work to the Code. Constructional rules 2. Checking in ClearCalcs, we can see that a 5.17 ft wide x 1 ft thick footing efficiently makes full use of the bearing capacity. Notice that we don't use the reduced companion live load - in this case, since we only have dead and live loads, this won't affect the results, and since we don't know the source of the live load it's conservative not to reduce the live load. With these criteria in mind, we can select our reinforcement - using the textbook's approximation for required steel area, we find we can use either #5 bars at 11 inches O.C. $$ q_u = \frac{1.2 \times 10\text{ kip/ft} + 1.6 \times 12.5 \text{ kip/ft}}{5.17 \text{ ft}} = 6 190 \text{ psf} $$ Note that we are taking the net bearing pressure, which does not include the weight of the soil above the footing and the self-weight. The 2012 edition of the Reinforced Concrete Design Manual [SP-17(11)] was developed in accordance with the design provisions of ACI 318-11, and is consistent with the format of SP-17(09). In this case since we only have dead and live loads, it is clear that the governing load combination will be 1.2D + 1.6L. We thus need to factor the loads. With our 12-inch thick footing, we need a minimum of 3 inches cover (*ACI 318-14, Table 20.6.1.3.1*). Resistance to eccentric compression 4. Assume a grout spacing of 48 in. Footings almost never have shear reinforcement - it is usually preferable to increase the footing thickness. 2.5” clear to strength steel #5@12” rather than the designed #5@10” BENDING STRENGTH OF THE SECTION HAS BEEN REDUCED BY ABOUT 16%. This mostly comes from the confinement factor, since our footing has large cover and spacing between bars this greatly benefits the development length. $$ \begin{aligned} \phi M_n &= \phi A_s f_y\left(d - a/2 \right) \\ &= 0.90 \times 0.34\text{ in}^2\text{/ft} \times 60000 \text{ psi} \left(9.5\text{ in} - \frac{0.667\text{ in}}{2} \right) \\ &= 14.0 \text{ kip-ft/ft} \end{aligned} $$ Note that in this example, $d$ was kept at 9.5 inches even though it would be slightly larger, since we are using #4 bars with half the diameter $d_b$. We thus only need to calculate the factored concrete shear strength $\phi V_c$, which is given by ACI 318-14 Cl 22.5.5.1: $$ \phi V_c = \phi 2\lambda \sqrt{f'_c}d $$ For shear, ACI 318-14 Table 21.2.1 specifies $\phi = 0.75$ and we're using normal-weight concrete so $\lambda = 1.0$. In this example, the structural design of the three retaining wall components is performed by hand. Once we have this, we can calculate the self-weight: $$ SW = 12 \text{ in} \cdot 150 \frac{\text{lb}}{\text{ft}^3} = 150 \text{ psf} $$ Once we know the self-weight, we immediately remove it from the allowable bearing pressure, together with the weight of the soil above the footing, and then divide the total load by this adjusted bearing pressure to find the required area. The allowable soil pressure is 5,000 psf and the its density is of 120 pcf. The ten design standards, known as the Eurocodes, will affect all design and construction activities as current British Standards for design … We must also verify that we are meeting minimum steel area requirements are met: $$ A_s = 0.0018h= 0.0018 \times 13 \text{ in} \times 12 \text{ in/ft} \\ = 0.281 \text{ in}^2\text{/ft} $$ And the maximum spacing is the minimum of $3H$ and 18 inches - the latter usually governs for footings. Shear wall section and assumed reinforcement is investigated after analysis to verify suitability for the applied loads. The last failure mode which we need to check is the bending of the footing. CE 437/537, Spring 2011 Retaining Wall Design Example 1 / 8 Design a reinforced concrete retaining wall for the following conditions. The slab has to carry a distributed permanent action of 1.0 kN/m2 (excluding slab self-weight) and … coefÞcient of friction is 0.4 and the unit weight of reinforced concrete is 24 kNm 3 1. The o.c. design example 3 reinforced strip foundation builder s. chapter 3 building planning residential code 2009 of. Since we are now dealing with concrete design, we use the ACI 318-14 standard, which is based on LRFD design. It presents the principles of the design of concrete ele-ments and of complete structures, with practical illustrations of the theory. First, it increases the capacity by providing a greater value of $d$. All that's left here is to find the size and spacing required. Detailings of individual . 2 Version 2.3 May 2008 types of members are included in the respective sections for the types, though Wall: 12-in. The fluid level inside We pick a 13-inch thick footing and repeat the previous steps: $$ \begin{aligned} d &= 9.5 \text{ in} \\ V_u &= 8.01 \text{ kip/ft} \\ \phi V_c &= 9.37\text{ kip/ft} \end{aligned} $$ We see that the 1-inch increase both decreased $V_u$ and increase $\phi V_c$ as we liked. Reinforced Concrete Cantilever Retaining Wall Design Example is 456 2000 indian standard code book for rcc design. Since in this case we are given the depth to the bottom of the footing, we can enter "=5 ft -H", and the calculator will automatically update the depth of soil above the footing when we update the footing thickness - just like an Excel spreadsheet. Concrete strength is 3,000 psi and reinforcement strength is 60,000 psi. Design concrete shear stress in wall section for out-of-plane bending ... Reinforced Concrete Stocky wall is where the effective height (He) divided by the thickness (h) does not exceed 15 for a braced wall and 10 for an unbraced wall. The textbook recommends using a value of 1-1.5 times the wall thickness for the footing thickness. The wall height is 17′. f'c = 3000 psi fy = 60 ksi Natural Soil Development of Structural Design Equations. The highest groundwater table is expected to be 4′ below grade. Design the reinforcement in the wall at its base and mid-height. We need to estimate the required thickness of the footing, since the self-weight of the footing is usually quite significant. ²î`bŠ“sø'D”»?¶î07v¤ÐÎÁxƄh‡¿éóê¾È»KÅ^Žšô5ü^¼ w&Âõ>WÐ{²þQà?¼riJ@íÓd ‹Íêç“àÖ. Using the CivilWeb Concrete Shear Wall Design Spreadsheet the designer can complete a full RC shear wall analysis and design in minutes. We go to ACI 314-18's chapter 25 to calculate the bonding length. 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