Ballrooms and banquet rooms should be located on lower floors and served by separate elevators. Sometimes it is advisable to provide an express elevator to serve heavy roof-garden traffic. Passenger elevators should be of 3000-lb capacity or more to allow room for baggage carriers. Intervals for passenger elevators should not exceed 50 s. Service elevators are very important in hotels. Hospital-shaped elevators are often preferred for handling linen and food service carts as well as baggage. Typically, hotels are provided with one passenger elevator per 125 to 150 rooms. The service elevator quantity is 50 to 60% of the passenger elevator quantity. The ratio of rooms per elevator is lower for better-quality hotels and higher for more modest facilities. Elimination of noise and vibration from medium- to high-speed elevators is virtually impossible, so hotels should be carefully planned to ensure that guest rooms are not adjacent to elevator hoistways. Rooms that adjoin elevator hoistways may generate complaints throughout the life of the building. 16.11.7 Apartment-Building Elevators Multistory residential buildings do not have peaks so pronounced as other types of buildings. Generally, the evening peak is the largest. Traffic flow at that time may be 6 to 8% of the building population in a 5-min period. Building population should be estimated in consideration of the market for which the building is designed. If only one elevator is selected to satisfy traffic conditions for a building of modest height, residents will be forced to use the stairs at times the elevator is out of service for repairs. Where the elevator is considered more than an amenity, two elevators should be provided. Market conditions may require that a separate service elevator also be provided in some urban settings. Typically, a 2500-lb elevator with a 9-ft clear ceiling height can be relied on to carry most furniture. As is the case with hotels, the potential for noise and vibration should be considered in location of elevators in living units. 16.11.8 Department-Store Elevators Department stores should be served by a coordinated system of escalators and elevators. The required capacity of the vertical-transportation system should be based on the transportation of merchandising area and the maximum density to which it is expected to be occupied by shoppers. The transportation area is all the floor space above or below the first floor to which shoppers and employees must be moved. Totaling about 80 to 85% of the gross area of each upper floor, the transportation area includes the space taken up by counters, showcases, aisles, fitting rooms, public rooms, restaurants, credit offices, and cashiers counters but does not include kitchens, general offices, accounting departments, stockrooms, stairways, elevator shafts, or other areas for utilities. The transportation capacity is the number of persons per hour that the verticaltransportation system can distribute from the main floor to the other merchandising floors. The ratio of the peak transportation capacity to the transportation area is called the density ratio. This ratio is about 1 to 20 for a busy department store. So the required hourly handling capacity of a combined escalator and elevator system is numerically equal to one-twentieth, or 5%, of the transportation area. The elevator system generally is designed to handle about 10% of the total. The maximum peak hour usually occurs from 12 to 1 pm on weekdays and between 2 and 3 pm on Saturdays. The type of elevator preferred for use with moving stairs is one with 3500-lb capacity or more. It should have center-opening, solid-panel, power-operated car and hoistway doors, with at least a 4-ft 2-in opening and a platform 7 ft 8 in by 4

Place the spirit level on the top of the course of bricks to be levelled, and gently tap the bricks, not the level as shown in the illustration. If we need to make excessive adjustments, it could be that we will need to remove bricks in that course and adjust the thickness of the bed joint. Think of the quoin (or corner) brick as a control point to which we refer for the rest of each course. Quoin Check out some tool catalogues online and find out how much a quality spirit level costs. Whats the most expensive level you can find? Spirit level being used to level top course of brickwork When only one course is laid, it is virtually impossible to plumb it accurately. Start careful plumbing from the second course. To keep the spirit level stable, place your foot against the bottom of the level whilst holding the top of the level with your free hand. Carefully adjust the bricks at either end of a course and look down the face of the wall to make sure it lines up with the spirit level. When making adjustments, once again, never strike the spirit level to plumb a quoin.

specified concrete compressive strength, psi d
effective depth of wall, but not to be taken larger than 80% of the wall length h
wall thickness Shear carried by the concrete should not exceed the smaller of the values of Vc computed from Eq. (9.112) or (9.113). N d V
3.3

hd  u (9.112) c c 4Lw where Nu
factored vertical axial load on wall acting with Vu, including tension due to shrinkage and creep (positive for compression, negative for tension). L (1.25

 0.2N /L h) w c uw V
0.6

  hd (9.113) c c M /V  L /2 u u w where Mu
factored moment at section where Vu acts. Alternatively, Vc
may be used if Nu 2

hd causes compression. Shear c strength Vc computed for a section at a height above the base equal to Lw/2 or onehalf the wall height, whichever is smaller, may be used for all lower sections. When Vu  0.5Vc, the area of horizontal shear reinforcement within a distance s2 required for shear is given by (V /  V )s A
u s 2 0.0025hs (9.114) h d 2 y where s2
spacing of horizontal reinforcement (max  Lw/5  3h  18 in) and y
yield strength of the reinforcement. Also, when Vu  0.5Vc, the area of vertical shear reinforcement with spacing s should be at least FIGURE 9.57 Components of a fixed arch. L A A
0.0025  0.5 2.5  h  h  0.0025 hs 0.0025hs (9.115) vh L nL w h where Lh is the wall height. But Avh need not be larger than Ah computed from Eq. (9.114). Spacing s should not exceed Lw/3, 3h, or 18 in. Arches are used in roofs for such buildings as hangars, auditoriums, gymnasiums, and rinks, where long spans are desired. An arch is essentially a curved beam with the loads, applied downward in its plane, tending to decrease the curvature. Arches are frequently used as the supports for thin shells that follow the curvature of the arches. Such arches are treated in analysis as two-dimensional, whereas the thin shells behave as three-dimensional elements. The great advantage of an arch in reinforced concrete construction is that, if the arch is appropriately shaped, the whole cross section can be utilized in compression under the maximum (full) load. In an ordinary reinforced concrete beam, the portion below the neutral axis is assumed to be cracked and does not contribute to the bending strength. A beam can be curved, however, to make its axis follow the lines of thrust very closely for all loading conditions, thus virtually eliminating bending