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Architectural code - The code covers general requirements for buildings, sites, and existing structures. It also outlines administration and enforcement of the code. The goal is to have standards that promote good building practices while keeping up with advances in technology. National Structural...

Architectural code - The code covers general requirements for buildings, sites, and existing structures. It also outlines administration and enforcement of the code. The goal is to have standards that promote good building practices while keeping up with advances in technology. National Structural code of the Philippines NSCP --The National Structural Code of the Philippines (NSCP) 2015 is a Structural design code that guides structural and civil engineers in designing and assessing buildings and other structures. The NSCP provides a standard set of criteria for structures\' design, construction, and upkeep. **SECTION 104** **DESIGN REQUIREMENTS** **104.1 Strength Requirement** Buildings, towers and other vertical structures and all portions thereof shall be designed and constructed to sustain, within the limitations specified in this code, all loads set forth in Chapter 2 and elsewhere in this code, combined in accordance with Section 203. Design shall be in accordance with Strength Design, Load and Resistance Factor Design and Allowable Stress Design methods, as permitted by the applicable material chapters. **SECTION 202** **DEFINITIONS** The following terms are defined for use in this chapter: **AWNING** is an architectural projection that provides weather protection, identity or decoration and is wholly supported by the building to which it is attached. **BALCONY, EXTERIOR,** is an exterior floor system projecting from and supported by a structure without additional independent supports. **DEAD LOADS** consist of the weight of all materials and fixed equipment incorporated into the building or other structure. **DECK** is an exterior floor system supported on at least two opposing sides by an adjacent structure and/or posts, piers, or other independent supports. **FACTORED LOAD** is the product of a load specified in Sections 204 through 208 and a load factor. See Section203.3 for combinations of factored loads. **LIVE LOADS** are those loads produced by the use and occupancy of the building or other structure and do not include dead load, construction load, or environmental loads such as wind load, earthquake load and fluid load. **LOADS** are forces or other actions that result from the weight of all building materials, occupants and their possessions, environmental effects, differential movements, and restrained dimensional changes. Permanent loads are those loads in which variations over time are rare or of small magnitude. All other loads are variable loads. **LOAD AND RESISTANCE FACTOR DESIGN** **(LRFD) METHOD** is a method of proportioning and designing structural elements using load and resistance factors such that no applicable limit state is reached when the structure is subjected to all appropriate load combinations. The term \"LRFD\" is used in the design of steel structures. **OCCUPANCY** is the purpose for that a building, or part thereof, is used or intended to be used. **STRENGTH DESIGN** is a method of proportioning and designing structural members such that the computed forces produced in the members by the factored load do not exceed the member design strength. The term strength design is used in the design of concrete structures. **BEARING WALL** is any wall meeting either of the following classifications: 1\. Any metal or wood stud wall that supports more than 1.45 kN/m of vertical load in addition to its own weight. 2\. Any masonry or concrete wall that supports more than 2.90 kN/m of vertical load in addition to its own weight. **EXTERIOR WALL** is any wall or element of a wall, or any member or group of members, that defines the exterior boundaries or courts of a building and that has a slope of 60 degrees or greater with the horizontal plane. **NONBEARING WALL** is any wall that is not a bearing wall. **PARAPET WALL** is that part of any wall entirely above the roof line. **RETAINING WALL** is a wall designed to resist the lateral displacement of soil or other materials. **SECTION 203** **COMBINATIONS OF LOADS** Buildings, towers and other vertical structures and all portions thereof shall be designed to resist the load combinations specified in Section 203.3 or 203.4 and, where required by Section 208, or Chapter 4 and the special seismic load combinations of Section 203.5. **203.2 Symbols and Notations** *D* = dead load *E* = earthquake load set forth in Section 208.5.1.1 *Em* = estimated maximum earthquake force that can be developed in the structure as set forth in Section 208.5.1.1 *F* = load due to fluids with well-defined pressures and maximum heights *H* = load due to lateral pressure of soil and water in soil *L* = live load, except roof live load, including any permitted live load reduction *Lr* = roof live load, including any permitted live load reduction *P* = ponding load *R* = rain load on the undeflected roof *T* = self-straining force and effects arising from contraction or expansion resulting from temperature change, shrinkage, moisture change, creep in component materials, movement due to differential settlement, or combinations thereof *W* = load due to wind pressure **203.3 Load Combinations using Strength Design or** **Load and Resistance Factor Design** **203.3.1 Basic Load Combinations** Where load and resistance factor design is used, structures and all portions thereof shall resist the most critical effects from the following combinations of factored loads: 1.4(*D*)(*F*) (203-1) 1.2(*D+F*+*T*)+1.6(*L*+*H*)+0.5(*Lror R*) (203-2) 1.2*D*+1.6(*Lr or R*)+(*f*1*L or* 0.8*W*) (203-3) 1.2*D*+1.6*W*+ *f*1*L*+0.5(*Lr or R*) (203-4) 1.2*D*+1.0*E*+ *f*1*L* (203-5) 0.9*D*+1.6 *W*+1.6*H* (203-6) 0.9*D*+1.0 E+1.6*H* (203-7) where: *f1* = 1.0 for floors in places of public assembly, for live loads in excess of 4.8 kPa, and for garage live load = 0.5 for other live loads *Exception:* *Factored load combinations for structural concrete per* *Section 409.3.* **203.3.2 Other Loads** Where *P* is to be considered in design, the applicable load shall be added to Section 203.3.1 factored as 1.2*P*. **203.4 Load Combinations Using Allowable Stress** **Design** **203.4.1 Basic Load Combinations** Where allowable stress design (working stress design) is used, structures and all portions thereof shall resist the most critical effects resulting from the following combinations of loads: *D*+*F* (203-8) *D*+*H*+*F*+*L*+*T* (203-9) *D*+*H*+*F*+(*Lror R*) (203-10) *D*+*H*+*F*+0.75\[(*L*+*T*+(*Lror R*)\] (203-11) **203.5 Special Seismic Load Combinations** For both allowable stress design and strength design, the following special load combinations for seismic design shall be used as specifically required by Section 208, or by Chapters 3 through 7. 1.2*D*+ *f*1*L*+1.0*Em* (203-19) 0.9*D*+1.0*Em* (203-20) where *f1* = 1.0 for floors in places of public assembly, for live loads in excess of 4.8 kPa, and for garage live load. = 0.5 for other live loads *Em* = the maximum effect of horizontal and vertical forces as set forth in Section 208.5.1.1 **SECTION 204** **DEAD LOADS** **204.1 General** Dead loads consist of the weight of all materials of construction incorporated into the building or other structure, including but not limited to walls, floors, roofs, ceilings, stairways, built-in partitions, finishes, cladding and other similarly incorporated architectural and structural items, and fixed service equipment, including the weight of cranes. **204.2 Weights of Materials and Constructions** The actual weights of materials and constructions shall be used in determining dead loads for purposes of design. In the absence of definite information, it shall be permitted to use the minimum values in Tables 204-1 and 204-2. **204.3 Partition Loads** Floors in office buildings and other buildings where partition locations are subject to change shall be designed to support, in addition to all other loads, a uniformly distributed dead load equal to 1.0 kPa of floor area. **SECTION 205** **LIVE LOADS** **205.1 General** Live loads shall be the maximum loads expected by the intended use or occupancy but in no case shall be less than the loads required by this section.  **206.6 Retaining Walls** Retaining walls shall be designed to resist loads due to the lateral pressure of retained material in accordance with accepted engineering practice. Walls retaining drained soil, where the surface of the retained soil is level, shall be designed for a load, *H*, equivalent to that exerted by a fluid weighing not less than 4.7 kPa per meter of depth and having a depth equal to that of the retained soil. Any surcharge shall be in addition to the equivalent fluid pressure. Retaining walls shall be designed to resist sliding by at least 1.5 times the lateral force and overturning by at least 1.5 times the overturning moment, using allowable stress design loads. **SECTION 207** **WIND LOADS**  **SECTION 208** **EARTHQUAKE LOADS** **BASE** is the level at which the earthquake motions are considered to be imparted to the structure or the level at which the structure as a dynamic vibrator is supported. **BASE SHEAR, *V,*** is the total design lateral force or shear at the base of a structure. **MOMENT-RESISTING FRAME** is a frame in which members and joints are capable of resisting forces primarily by flexure. **STORY DRIFT** is the lateral displacement of one level relative to the level above or below. **SUBDIAPHRAGM** is a portion of a diaphragm used to transfer wall anchorage forces to diaphragm cross ties. **208.4.4.1 Seismic Zone** The Philippine archipelago is divided into two seismic zones only. Zone 2 covers the provinces of Palawan, Sulu and Tawi-Tawi while the rest of the country is under Zone 4 as shown in Figure 208-1. Each structure shall be assigned a seismic zone factor Z, in accordance with Table 208-3. **208.5.2 Static Force Procedure** **208.5.2.1 Design Base Shear** The total design base shear in a given direction shall be determined from the following equation:*\ *The total design base shear need not exceed the following: The total design base shear shall not be less than the following:  In addition, for Seismic Zone 4, the total base shear shall also not be less than the following:  Chapter 4 -- Structural concrete: **ADMIXTURE** is material other than water, aggregate, or hydraulic cement used as an ingredient of concrete and added to concrete before or during its mixing to modify its properties. **AGGREGATE** is granular material, such as sand, gravel, crushed stone and iron blast-furnace slag, and when used with a cementing medium forms a hydraulic cement concrete or mortar **BONDED TENDON** is a prestressing tendon that is bonded to concrete either directly or through grouting. **COLUMN** is a member with a ratio of height-to-leastlateral dimension of 3 or greater used primarily to support axial compressive load. For a tapered member, the least lateral dimension is the average of the top and bottom dimensions of the smaller side. **CONCRETE** is a mixture of portland cement or any other hydraulic cement, fine aggregate, coarse aggregate and water, with or without admixtures. **DESIGN LOAD COMBINATIONS** are the combination of factored loads and forces in Section 409.3. **DESIGN STORY DRIFT RATIO** is the relative difference of design displacement in between the top and bottom of a story, divided by the story height. See Section 421. **DEVELOPMENT LENGTH** is the length of embedded reinforcement required to develop the design strength of reinforcement at a critical section. See Section 409.4.3. **EFFECTIVE DEPTH OF SECTION** (*d*) is the distance measured from extreme compression fiber to centroid of tension reinforcement. **EFFECTIVE PRESTRESS** is the stress remaining in prestressing tendons after all losses have occurred, excluding effects of dead load and superimposed load. **EMBEDMENT LENGTH** is the length of embedded reinforcement provided beyond a critical section. **MODULUS OF ELASTICITY** is the ratio of normal stress to corresponding strain for tensile or compressive stresses below proportional limit of material. See Section 408.6. **PEDESTAL** is an upright compression member with a ratio of unsupported height to average least lateral dimension not exceeding 3. For a tapered member, the least lateral dimension is the average of the top and bottom dimensions of the smaller side. **POST-TENSIONING** is a method of prestressing in which tendons are tensioned after concrete has hardened. **PRECAST CONCRETE** is a structural concrete element cast in other than its final position in the structure. **PRESTRESSED CONCRETE** is structural concrete in which internal stresses have been introduced to reduce potential tensile stresses in concrete resulting from loads. **PRETENSIONING** is a method of prestressing in which tendons are tensioned before concrete is placed. **REINFORCED CONCRETE** is structural concrete reinforced with no less than the minimum amounts of prestressing tendons or nonprestressed reinforcement specified in this chapter. **REINFORCEMENT** is material that conforms to Section 403.6, excluding prestressing tendons unless specifically included. **STIRRUP** is reinforcement used to resist shear and torsion stresses in a structural member; typically bars, wires, or welded wire fabric (plain or deformed) bent into *L*, *U* or rectangular shapes and located perpendicular to or at an angle to longitudinal reinforcement. The term \"stirrups\'\' is usually applied to lateral reinforcement in flexural members and the term \"ties\'\' to those in compression members. See also \"Tie.\" **STRENGTH, DESIGN** is the nominal strength multiplied by a strength-reduction factor, . See Section 409.4. **STRENGTH, NOMINAL** is the strength of a member or cross section calculated in accordance with provisions and assumptions of the strength design method of this chapter before application of any strength-reduction factors. See Section 409.4.1. **STRENGTH, REQUIRED** is the strength of a member or cross section required to resist factored loads or related internal moments and forces in such combinations as are stipulated in this chapter. See Section 409.2.1. **YIELD STRENGTH** is the specified minimum yield strength or yield point of reinforcement in MPa. Yield strength or yield point shall be determined in tension according to applicable ASTM standards as modified by Section 403.6 of this code. **SECTION 404** **DURABILITY REQUIREMENTS** **404.1 Notation** *f\'c* = specified compressive strength of concrete, MPa. *w*/*cm* = maximum water-cementitious material ratio. **SECTION 407 DETAILS OF** **REINFORCEMENT** **407.1 Notations** *d* = distance from extreme compression fiber to centroid of tension reinforcement, mm *db* = nominal diameter of bar, wire or prestressing strand, mm *f\'ci* = compressve strength of concrete at time of initial prestress, MPa *fy* = specified yield strength of nonprestressed reinforcement, MPa *Ld* = development length, mm. See Section 412. **407.2 Standard Hooks** *\"Standard hook\'\'* as used in this code is one of the following: **407.2.1** 180-degree bend plus 4*db* extension, but not less than 60 mm at free end of bar. **407.2.2** 90-degree bend plus 12*db* extension at free end of bar. **407.2.3** For stirrup and tie hooks: 1\. ɸ16 mm bar and smaller, 90-degree bend plus 6*db* extension at free end of bar; or 2\. ɸ20 mm and ɸ25 mm bar, 90-degree bend, plus 12*db* extension at free end of bar; or 3\. ɸ25 mm bar and smaller, 135-degree bend plus 6*db* extension at free end of bar. **407.2.4** Seismic hooks as defined in Section 402. **SECTION 408 ANALYSIS AND** **DESIGN** **GENERAL CONSIDERATIONS** **408.4.3** As an alternate to frame analysis, the following approximate moments and shears shall be permitted to be used in design of continuous beams and one-way slabs (slabs reinforced to resist flexural stresses in only one direction), provided: 1\. There are two or more spans; 2\. Spans are approximately equal, with the larger of two adjacent spans not greater than the shorter by more than 20 percent; 3\. Loads are uniformly distributed; 4\. Unfactored live load, *L*, does not exceed three times unfactored dead load, *D*; and 5. Members are prismatic. **408.11 Columns** **408.11.1** Columns shall be designed to resist the axial forces from factored loads on all floors or roof and the maximum moment from factored loads on a single adjacent span of the floor or roof under consideration. Loading condition giving the maximum ratio of moment to axial load shall also be considered. **SECTION 409 STRENGTH AND** **SERVICEABILITY REQUIREMENTS** **409.3 Required Strength** **409.3.1** Required strength *U* shall be at least equal to the effects of factored loads in Eq. 409-1 through Eq. 409-7. The effect of one or more loads not acting simultaneously shall be investigated. *U =* 1.4(*D + F*) (409-1) *U* = 1.2 (*D+ F+T* ) + 1.6 (*L*+*H*) + 0.5(*L*, or *R*) (409-2) *U* = 1.2 *D* + 1.6 (*L*, or *R*) + (1.0*L* or 0.80 *W*) (409-3) *U* = 1.2 *D +* 1.6 *W* + 1.0 *L +0*.5 (*L*, or *R*) (409-4) *U* = 1.2 *D* + 1.0 *E*+ 1.0 *L* (409-5) *U* = 0.9 *D +* 1.6 *W +* 1.6 *H* (409-6) *U* = 0.90 *D* + 1.0 *E* + 1.6 *H* (409-7) **409.3 Required Strength** **409.3.1** Required strength *U* shall be at least equal to the effects of factored loads in Eq. 409-1 through Eq. 409-7. The effect of one or more loads not acting simultaneously shall be investigated. *U =* 1.4(*D + F*) (409-1) *U* = 1.2 (*D+ F+T* ) + 1.6 (*L*+*H*) + 0.5(*L*, or *R*) (409-2) *U* = 1.2 *D* + 1.6 (*L*, or *R*) + (1.0*L* or 0.80 *W*) (409-3) *U* = 1.2 *D +* 1.6 *W* + 1.0 *L +0*.5 (*L*, or *R*) (409-4) *U* = 1.2 *D* + 1.0 *E*+ 1.0 *L* (409-5) *U* = 0.9 *D +* 1.6 *W +* 1.6 *H* (409-6) *U* = 0.90 *D* + 1.0 *E* + 1.6 *H* (409-7)