RCD 1,2&3 PDF Reinforced Concrete Design

INTRODUCTION I N S T R U C T O R : E N G R. M A. R A S H I E L A H. R E S U R R E C C I O N , R C E , S O 2 PROFESSIONAL COURSE 4 REINFORCED CONCRETE DESIGN 1. Distinguish between different structural elements and their roles within the built environment. 2. Evaluate the significance...

INTRODUCTION I N S T R U C T O R : E N G R. M A. R A S H I E L A H. R E S U R R E C C I O N , R C E , S O 2 PROFESSIONAL COURSE 4 REINFORCED CONCRETE DESIGN 1. Distinguish between different structural elements and their roles within the built environment. 2. Evaluate the significance of specifications and building codes in ensuring structural integrity and safety. LEARN MORE IDENTIFICATION OF THE STRUCTURES Types of Structures 1. Residential Structures (Houses, Apartments, Townhouse) 2. Commercial Structures (Offices, Retail Stores, Restaurants) 3. Industrial Structures (Factories, Warehouses, Power Plants) 4. Infrastrusture Structures (Bridges, Highways, Dams, Tunnels) Structural Elements 1. Beams - Horizontal elements designed to support loads from vertical or horizontal forces. 2. Columns - Vertical elements that transfer loads from beams and slabs to the foundation. 3. Slabs - Flat horizontal surfaces that provide floors or ceilings. 4. Foundation - The part of the structure that transfers loads to the ground and provides stability.  Objective SPECIFICATIONS To introduce the importance of building codes and specifications OF BUILDING CODE in reinforced concrete design.  Building Codes: Purpose: Building codes are regulations that ensure structures are safe, healthy, and durable. They set minimum standards for design and construction. Components: Load Requirements: Specifies how much load different elements of a structure must support. Material Specifications: Details on the quality and type of materials used, such as concrete mix and reinforcement. Construction Practices: Guidelines for construction methods and practices. Major Building Code: "National Building Code of the Philippines" or NBCP, officially known as Presidential Decree No. 1096. PHILOSOPHIES OF DESIGN To understand different approaches to design in reinforced concrete.  01 02 03 Safety Functionality Economy The most important thing is Structures should work well for Designs should be cost-effective: making sure that buildings, their intended purpose: Material Efficiency: Using bridges, and other structures don’t Buildings: Must be materials wisely to avoid collapse or fail: comfortable and usable for wastage. Load Capacity: Structures must their occupants. Construction Costs: Balancing support the maximum weight Bridges: Should allow smooth quality with costs to avoid or force they will encounter. traffic flow. overspending. Failure Prevention: Designing to prevent problems like cracks or collapses. FACTOR OF SAFETY – ASD AND LRFD METHODS Allowable Stress Design (ASD) ASD is a simple way to ensure safety: Safe Stress Levels: Structures are designed so the maximum stress (force) is below a safe limit. Safety Factor: This is a cushion to account for uncertainties. For example, if concrete can handle 100 units of stress, we might only use it up to 50 units in our design. FACTOR OF SAFETY – ASD AND LRFD METHODS L o a d a n d R e s i s t a n c e F a c t o r D e s i g n ( L R F D ) L R F D i s a b i t m o r e a d v a n c e d : Load Factors: Adjusts for the possibility that loads might be heavier than expected. Resistance Factors: Adjusts for uncertainties in how strong materials might be. P r o s : More Accurate: Provides a better balance of safety for complex scenarios. C o n s : C o m p l e x : R e q u i r e s m o r e c a l c u l a t i o n s a n d u n d e r s t a n d i n g o f f a c t o r s. GRAVITY LOADS ON STRUCTURE BY: Ong, Xavier Levi C. Siruno, Deo Angelo M. Zabala, Edgardo III M. CONTENT ⚬ ⚬ ⚬ INTRODUCTION Classification of Loads ⚬ ⚬ ⚬ ⚬ Direction of the load ⚬ ⚬ Gravity Loads ⚬ ⚬ Gravity Loads ⚬ DEAD LOADS DESCRIPTION ⚬ ⚬ ⚬ ⚬ ⚬ ⚬ ⚬ ⚬ ⚬ ⚬ ⚬ ⚬ ⚬ Dead Loads Weight of Materials and Construction Partition Loads and Access Floor System Table 204-1 Minimum Densities for Design Loads from Materials (kN/m3) Table 204-1 Minimum Densities for Design Loads from Materials (kN/m3) Table 204-2 Minimum Design Loads (kPa) Table 204-2 Minimum Design Loads (kPa) LIVE LOADS General Floor Live Loads Distribution of Uniform Floor Loads Concentrated Floor Loads Concentrated Floor Loads ² Table 205-1 Minimum Uniform and Concentrated Live Loads Table 205-1 Minimum Uniform and Concentrated Live Loads (continued) Table 205-1 Minimum Uniform and Concentrated Live Loads (continued) Table 205-1 Minimum Uniform and Concentrated Live Loads (continued) Special Loads Table 205-2 Special Loads Table 205-2 Special Loads (continued) Roof Live Loads Distribution of Loads  ² Unbalanced Loading Unbalanced Loading Special Roof Loads Reduction of Live Loads ² ² Reduction of Live Loads ² ² Reduction of Live Loads Alternate Floor Live Load Reduction ² ² ² ² Table 205-3 Minimum Roof Live Loads OTHER MINIMUM LOADS General Other Loads IMPACT LOADS ELEVATORS MACHINERY ANCHORAGE OF CONCRETE AND MASONRY WALLS INTERIOR WALL LOADS EXCEPTION RETAINING WALLS WATER ACCUMULATION UPLIFT ON FLOORS AND FOUNDATIONS CRANE LOADS MAXIMUM WHEEL LOAD VERTICAL IMPACT FORCE LATERAL FORCE LONGITUDINAL FORCES HELIPORT AND HELISTOP LANDING AREAS ² Thank You  THQU AKE WIND EAR THQU AKE W LATERAL LOADS ON STRUCTURES PRESENTED BY: ADS L RAL LO LATE MILO, RACHELL KAYE ANN LOADS TERAL A OMAPAS, DAN ANDRO ADS L O REVILLAS, ALYSSA FE ERAL L LAT  NTEN S CO TE NT CON ENTS ONT S C TENT CON ENTS CODE PROVISIONS C101 ONT S C TENT WIND LOADS EARTHQUAKE LOADS OTHER LATERAL LOADS  Lateral loads are live loads that are applied horizontally, or parallel to the LATERAL ground, acting on a structure. This LOADS includes wind, seismic and earth loads. Lateral loads on a building are usually resisted by walls and bracing. AD SL ATE RA L LOA DS LAT ERA L LOA DS LAT E  LAT OADS AL L ATER DS L LOA ERAL LAT OADS AL L ATER DS L LOA CODE PROVISIONS ERAL NSCP C101 RACHELL KAYE ANN R. MILO SECTION 207 WIND LOADS Specifications: Buildings and other vertical structures shall be designed and constructed to resist wind loads as specified and presented in Section 207A through 207F of the NSCP 2015. Antenna towers and antenna supporting structures shall be designed and constructed to resist wind loads as specified and presented in ANSI/TIA-222-G-2005, entitled as “Structural Standards for Steel Antenna Towers and Antenna Supporting Structures – Addendum 1.” General Requirements Section 207A Provides the basic wind design parameters that are applicable to the various wind load determination methodologies outlined in Sections 207B through 207F. Items covered in Section 207A include definitions, basic wind speed, exposure categories, internal pressures, enclosure classification, gust-effects, and topographic factors, among others. General Requirements Section 207B Discusses about Directional Procedure for Enclosed, Partially Enclosed, and Open Buildings of All Heights: The procedure is the former "buildings of all heights method" in NSCP 2010 (ASCE 7-05), Method 2. A simplified procedure, based on the Directional Procedure, is provided for buildings up to 48m in height. General Requirements Section 207C Discusses about Envelope Procedure for Enclosed and Partially Enclosed Low-Rise Buildings: This procedure is the former "low-rise buildings method" in NSCP 2010 (ASCE 7-05) Method 2. This section also incorporates NSCP 2010 (ASCE 7-05) Method 1 for MWFRS applicable to the MWFRS of enclosed simple diaphragm buildings less than 18 m in height. General Requirements Section 207D Discusses Other Structures and Building Appurtenances: A single section is dedicated to determining wind loads on non-building structures such as signs, rooftop structures, and towers. General Requirements Section 207E Discusses about Components and Cladding. This code addresses the determination of component and cladding loads in a single section. Analytical and simplified methods are provided based on the building height. Provisions for open buildings and building appurtenances are also addressed. General Requirements Section 207F Discusses about Wind Tunnel Procedure. SECTION 208 EARTHQUAKE LOADS Purpose: The purpose of the succeeding earthquake provisions is primarily to design seismic-resistant structures to safeguard against major structural damage that may lead to loss of life and property. These provisions are not intended to assure zero- damage to structures nor maintain their functionality after a severe earthquake. General Requirements Section 208.4.1 The procedures and the limitations for the design of structures shall be determined considering seismic zoning, site characteristics, occupancy, configuration, structural system and height in accordance with this section. Structures shall be designed with adequate strength to withstand the lateral displacements induced by the Design Basis Ground Motion, considering the inelastic response of the structure and the inherent redundancy, overstrength and ductility of the lateral force-resisting system. General Requirements Section 208.4.1 The minimum design strength shall be based on the Design Seismic Forces determined in accordance with the static lateral force procedure of Section 208.5, except as modified by Section 208.5.3.5.4. Where strength design is used, the load combinations of Section 203.3 shall apply. Where Allowable Stress Design is used, the load combinations of Section 203.4 shall apply. Allowable Stress Design may be used to evaluate sliding or overturning at the soil-structure interface regardless of the design approach used in the design of the structure, provided load combinations of Section 203.4 are utilized. 1 WIND LOADS DAN ANDRO P. OMAPAS  Wind Loads Wind load refers to the force exerted by the wind on structures such as buildings, bridges, towers, and other infrastructure. SL ATE RA L LOA DS Wind Loads 01 Main Wind-Force Resisting System (MWFRS) elements of a building or structure that are specifically designed to resist and transfer wind loads safely to the foundation Section 207B. Directional procedure for buildings of all heights Section 207C. Envelope procedure for low-rise buildings Section 207D. Directional procedure for buildings appurtenances Section 207F. Wind tunnel procedure for any buidling or other structure 02 Components and Cladding (C&C) elements of a building's exterior that are not part of the primary structural system but are still essential for enclosing the building and protecting it from the elements Section 207E. Envelope Procedure, etc. Section 207F. Wind tunnel procedure for any buidling or other structure Wind Loads Main Wind-Force Resisting System (MWFRS) Section 207B. Directional procedure for buildings of all heights 1. Determine risk category of building or other strucuture (refer to Table 103-1 of NSCP) 2. Determine the basic wind speed, V, for the applicable risk category 3. Determine the six wind load parameters. 4. Determine velocity pressure exposure coefficient, 𝐾𝑧 or 𝐾ℎ (refer to Table 207B.3-1) 5. Determine velocity pressure ^𝑧 or ^ℎ using Eq. 207B.3-1 of NSCP 6. Determine external pressure coefficient, 𝐶𝑝 or 𝐶𝑛 based Fig. 207B.4-1 to 7. 7. Calculate wind pressure, p, on each building surface using Eq. 207B.4-1 to 3. Wind Loads (MWFRS) Section 207B. Directional procedure for buildings of all heights 1. Determine risk category of building or other structure (refer to Table 103-1 of NSCP) Wind Loads (MWFRS) Section 207B. Directional procedure for buildings of all heights 2. Determine the basic wind speed, V, for the applicable risk category 3. Determine the six wind load parameters. 01 Wind directionality factor, 𝐾d shall be determined from Table 207A.6-1 of NSCP. It is based on the structure type to be designed. For buildings, 𝐾𝑑 = 0.85. 3. Determine the six wind load parameters. 02 Exposure category based on ground surface roughness. It shall be determined from Figure C207A.7-2 of NSCP. Exposure B - urban, suburban with closely spaced obstructions Exposure C - open terrain with scattered obstructions (less then 9m in height) Exposure D - flat, unobstructed areas Topographic 03 only if the structure is located at either isolated hills, ridges, factor, 𝐾𝑧t and escarpments. When applicable, 𝐾𝑧𝑡 can be calculated based on Sec. 207A.8.2 of NSCP. 04 Gust effect factor, G The gust-effect factor for a rigid building or other structure is permitted to be taken as 0.85. 3. Determine the six wind load parameters. 05 Enclosure classification determined based on the amount of opening on the building envelope. 3. Determine the six wind load parameters. 1. Partially Enclosed Building: 05 The total area of openings in a wall that receives positive external pressure exceeds the sum of the areas of openings in Enclosure the balance of the building envelope (walls and roof) by more than 10%. classification The total area of openings in a wall that receives positive external pressure exceeds 0.37 sq.m. determined based on the 1% of the area of that wall, whichever is smaller, and the amount of opening on the percentage of openings in the balance of the building envelope building envelope. does not exceed 20%. 2. Open Building – each wall at least 80% open. 3. Enclosed Building - building that does not satisfy the conditions for partially enclosed or open building. 3. Determine the six wind load parameters. Internal pressure 06 coefficient, 𝐺𝐶𝑝i 03 shall be determined from Table 207A.11-1 of NSCP based on building enclosure classifications. Wind Loads (MWFRS) Section 207B. Directional procedure for buildings of all heights 4. Determine velocity pressure exposure coefficient, 𝐾𝑧 or 𝐾ℎ (refer to Table 207B.3-1) Wind Loads (MWFRS) Section 207B. Directional procedure for buildings of all heights 5. Determine velocity pressure ^𝑧 or ^ℎ using Eq. 207B.3-1 of NSCP Kz = velocity pressure exposure coefficient Kzt = Topographic factor Kd = wind directionality factor V = basic wind speed, m/s Wind Loads (MWFRS) Section 207B. Directional procedure for buildings of all heights 6. Determine external pressure coefficient, 𝐶𝑝 or 𝐶𝑛 based Fig. 207B.4-1 to Wind Loads (MWFRS) Section 207B. Directional procedure for buildings of all heights 7. Calculate wind pressure, p, on each building surface using Eq. 207B.4-1 to 3 q = velocity pressure exposure coefficient G = Topographic factor Cp = wind directionality factor qi = basic wind speed, m/s GCpi = – internal pressure coefficient (refer to Table 207A.11-1) Wind Loads (MWFRS) SAMPLE PROBLEM: A 3- story educational building has the following parameters: Roof mean height = 9 m Total height abouve the ground = 12 m Exposure Category : B Location: Daet, Camarines Norte Plan Dimension = 8 m x 9 m Gable roof with 15 degrees slope Total area of opening in every wall that receives positive external pressure is 0.20 m Wind direction parallel with the least dimension of the building Determine the design wind load on the structure. Wind Loads (MWFRS) Step 1: Risk category of building Category III - Special Occupancy Structures Step 2: Determine the basic wind speed, V Based on Fig. 207A.5-1A, V = 290 kph Note that V must be in meter per second. V = 290 km/h = 80.56 m/s Step 3. Determine the six wind load parameters. 3.1 Wind directionality factor 𝐾𝑑 = 0.85 3.2 Exposure category: B Wind Loads (MWFRS) 3.3 Topographic factor 𝐾𝑧𝑡 = 1.0 (since it is not located along hills or escarpment) 3.4 Gust effect factor G = 0.85 3.5 Enclosure classification Enclosed building since the opening does not exceed 0.37 sq.m. 3.6 Internal pressure coefficient 𝐺𝐶𝑝𝑖 = ±0.18 Wind Loads (MWFRS) Step 4: Determine velocity pressure exposure coefficient, 𝐾𝑧 or 𝐾ℎ To calculate 𝐾𝑧 (windward) Using the values z = 12m and Exposure B 𝐾𝑧 = 0.76 To calculate 𝐾ℎ (leeward wall and sidewall) Using the values h = 9m and Exposure B 𝐾ℎ = 0.70 Step 5: Determine velocity pressure 𝑞𝑧 or 𝑞ℎ using Eq. 207B.3-1 of NSCP @ windward wall @ leeward wall and side wall 𝒒𝒛 = 𝟎. 𝟔𝟏𝟑𝑲𝒛𝑲𝒛𝒕𝑲𝒅𝑽 𝒒𝒉 = 𝟎. 𝟔𝟏𝟑𝑲𝒉𝑲𝒛𝒕𝑲𝒅𝑽 𝑞𝑧 = 0.613(0.76)(1)(0.85)(80.562 ) 𝑞ℎ = 0.613(0.70)(1)(0.85)(80.562 ) ^𝑧 = 2,569.71 𝑁 𝑚2 = Ð. Ó Õ 𝒌𝑷𝒂 ^ℎ = 2,367.01 𝑁 𝑚2 = Ð. Ñ Õ 𝒌𝑷a Wind Loads (MWFRS) Step 6: Determine external pressure coefficient, 𝐶𝑝 or 𝐶𝑛 based Fig. 207B.4-1 to 7. windward wall, Cp = 0.8 leeward, Cp = -0.5 sidewall, Cp = -0.7 Roof, windward, Cp = 1.3 leeward, Cp = -0.6 Step 7: Calculate wind pressure, p, on each building surface using Eq. 207B.4-1 to 3. 𝒑 = 𝒒𝑮𝑪𝒑 − 𝒒𝒊(𝑮𝑪𝒑𝒊) - windward - leeward where 𝑞 = 𝑞𝑧 , 𝑞𝑖= 𝑞ℎ where 𝑞 = 𝑞ℎ, 𝑞𝑖= 𝑞ℎ 𝑝 = (2.57)(0.85)(0.8) − (2.37)(0.18) 𝑝 = (2.37)(0.85)(−0.5) − (2.37)(0.18) 𝒑 = 𝟎. Ï Ò 𝒌𝑷𝒂 𝒑 = − Ï. Ò Ñ 𝒌𝑷𝒂 𝑝 = (2.57)(0.85)(0.8) − (2.37)(−0.18) 𝑝 = (2.37)(0.85)(−0.5) − (2.37)(−0.18) 𝒑 𝒑 = Ð. Ï Õ 𝒌𝑷a = −𝟎. Ó Ö 𝒌𝑷a Wind Loads (MWFRS) Step 7: Calculate wind pressure, p, on each building surface using Eq. 207B.4-1 to 3. 𝒑 = 𝒒𝑮𝑪𝒑 − 𝒒𝒊(𝑮𝑪𝒑𝒊) Sidewall Roof For windward side, 𝑞 = 𝑞𝑧 , 𝑞𝑖= 𝑞ℎ where 𝑞 = 𝑞ℎ, 𝑞𝑖= 𝑞ℎ 𝑝 = (2.57)(0.85)(−1.3) − (2.37)(0.18) 𝑝 = (2.37)(0.85)(−0.7) − (2.37)(0.18) 𝒑 = − Ñ. Ð Õ 𝒌𝑷𝒂 𝒑 = − Ï. Ö Ò 𝒌𝑷𝒂 𝑝 = (2.57)(0.85)(−1.3) − (2.37)(−0.18) 𝒑 = − Ð. Ò Ï 𝒌𝑷𝒂 𝑝 = (2.37)(0.85)(0.8) − (2.37)(−0.18) 𝒑 = −𝟎. × Ö 𝒌𝑷a For leeward side, 𝑞 = 𝑞ℎ, 𝑞𝑖= 𝑞ℎ 𝑝 = (2.37)(0.85)(−0.6) − (2.37)(0.18) 𝒑 = − Ï. Ô Ò 𝒌𝑷𝒂 𝑝 = (2.37)(0.85)(−0.6) − (2.37)(−0.18) 𝒑 = −𝟎. Õ Ö 𝒌𝑷a  NTEN S CO TE NT CON ENTS ONT S C TENT CON ENTS CODE PROVISIONS C101 ONT S C TENT WIND LOADS EARTHQUAKE LOADS OTHER LATERAL LOADS  ADS E LO UAK THQ EARTHQUAKE LOADS EAR ADS AK U E LO HQ RT UAK EA DS A THQ LO KE EAR UA PRESENTED BY: THQ R EA DS S LOA REVILLAS, ALYSSA FE L. AD LO E AKE AK U HQ HQU  PURPOSE The purpose of the succeeding earthquake provisions is primarily to design seismic- resistant structures to safeguard against major structural damage that may lead to loss of life and property. These provisions are not intended to assure zero-damage to structures nor maintain their functionality after a severe earthquake. MINIMUM SEISMIC DESIGN AK Structures and portions thereof shall, as a minimum, be designed and constructed to EL resists the effects of seismic ground motions as provided in this section. OA DS EA RT SEISMIC AND WIND DESIGN HQ UA When the code-prescribed wind design produces greater effects, the wind design shall KE govern, but detailing requirements and limitations prescribed in this section and LO AD referenced sections shall be made to govern. S EA  BASIS FOR DESIGN OCCUPANCY CATEGORIES For purposes of earthquake- resistant design, each structure shall be placed in one of the AK occupancy categories listed in EL OA Table 103-1. Table 208-1 assigns DS important factors, I and Ip, and EA structural observation RT HQ requirements for each category. UA KE LO AD S EA  SOIL PROFILE TYPE AK EL OA DS EA RT HQ UA KE LO AD S EA AK EL OA DS EA RT HQ UA KE LO AD S EA  SITE SEISMIC HAZARD CHARACTERISTICS Seismic hazard characteristics for the site shall be established based on the seismic zone and proximity of the site to active seismic sourced, site soil profile characteristics and the structure’s importance factor. SEISMIC ZONE The Philippine archipelago is divided into two seismic zones only: AK EL Zone 2 – covers the provinces of Palawan (except Busuanga), Sulu and Tawi-Tawi OA Zone 4 – the rest of the country (shown in Figure 208-1) DS Each structure shall be assigned a seismic zone factor Z, in accordance with Table 208-3. EA RT HQ UA KE LO AD S EA  Figure 208-1 Referenced Seismic Map of the AK Philippines EL OA DS EA RT HQ UA KE LO AD S EA  SEISMIC SOURCE TYPES (TABLE 208-4 TO 8) AK EL OA DS EA RT HQ UA KE LO AD S EA  SEISMIC ZONE 4 NEAR SOURCE FACTOR In Seismic Zone 4, each site shall be assigned near-source factors in accordance with Tables 208-5 and 208- 6 based on the Seismic Source Type as AK set forth in Section 208.4.4.2. EL For high rise structures and essential OA DS facilities within 2. Km of a major fault, a EA site specific seismic elastic design RT response spectrum is recommended to HQ UA be obtained for the specific area. KE LO AD S EA  The value of Na used to determine Ca need not exceed 1.1 for structures complying with all the following conditions: 1. The soil profile type is 2. 3. Except in single-storey structures, residential building accommodating 10 or fewer persons, private garages, carports, sheds and agricultural buildings, moment frame systems designated as part of the lateral-force- EL OA resisting system shall be special moment-resisting frames. DS 4. The exceptions to Section 515.6.5 shall not apply, except for columns in EA RT one-storey or columns at the top storey of multistorey buildings. HQ UA 4. None of the following structural irregularities is present: Type 1, 4 or 5 of KE LO Table 208-9, and Type 1 or 4 of Table 208-10. AD S E  SEISMIC RESPONSE COEFFICIENTS Each structure shall be assigned a seismic coefficient, , in Ca accordance with Table 208-7 and a seismic AK coefficient, in accordance with Table EL OA 208-8. DS EA RT HQ UA KE LO AD S EA  CONFIGURATION REQUIREMENTS Each structure shall be designated as being structurally regular or irregular in accordance with Sections 208.4.5.1 and 208.4.5.2. REGULAR STRUCTURES Regular structures have no significant physical discontinuities in plan or vertical configuration or in their lateral-force-resisting systems such as the irregular features. IRREGULAR STRUCTURES LO Irregular structures have significant physical discontinuities in configuration or in their AD S lateral force-resisting systems. EA Structures having any of the features listed in Table 208-9 shall be designated as if having a RT HQ vertical irregularity. UA Structures having any of the features listed in Table 208-10 shall be designated as having a KE LO plan irregularity. A AK EL OA DS EA REGULAR STRUCTURES IRREGULAR STRUCTURES RT HQ UA KE LO AD S EA AK EL OA DS EA RT HQ UA KE LO AD S EA  EARTHQUAKE LOADS AND MODELING REQUIREMENTS Earthquake Loads Structures shall be designed for ground motion producing structural response and seismic forces in any horizontal direction. The following earthquake loads shall be used in the load combinations set forth in Section 203: EL OA DS EA RT HQ UA KE EL OA DS EA RT HQ UA KE EL OA DS EA RT HQ UA KE EL OA DS EA RT HQ UA KE  LAT OADS AL L ATER DS L LOA ERAL LAT OADS AL L ATER DS L LOA ERAL OTHER LATERAL LOAD RACHELL KAYE ANN R. MILO EARTH PRESSURE Earth pressure is the lateral pressure exerted by the soil on a shoring system. It depends on the type of soil and how it interacts or moves with the retaining structure. 3 MOST COMMON TYPE OF LATERAL SOIL LOAD AT REST STATE When the wall is stationary and back fill soil have no tendency to move. Under the rest condition the retaining wall is stationary therefore lateral stress will be zero. 3 MOST COMMON TYPE OF LATERAL SOIL LOAD ACTIVE PRESSURE Active state is developed when the wall moves away from the back fill. The active earth pressure is less than pressure at rest because the internal resistance is mobilize in the soil of back fill when wall moves away from the back fill. 3 MOST COMMON TYPE OF LATERAL SOIL LOAD PASSIVE PRESSURE In passive state, the wall is pushed towards the back fill. The passive earth pressure is greater than earth pressure at rest because shearing resistance is built up between two surface of soil mass. SOIL LATERAL LOADS SECTION 209 Basement, foundation and retaining walls shall be designed to resist lateral soil loads. Soil loads specified in Table 209- 1 shall be used as the minimum design lateral soil loads unless specified otherwise in a soil investigation report approved by the building official. Basement walls and other walls in which horizontal movement is restricted at the top shall be designed for at-rest pressure. Retaining walls free to move and rotate at the top are permitted to be designed for active pressure. Design lateral pressure from surcharge loads shall be added to the lateral earth pressure load. Design lateral pressure shall be increased if soils with expansion potential are present at the site. TABLE 209.1 - SOIL LATERAL LOAD THANK YOU FOR LISTENING