Soil bearing and stability 8.
Mass concrete retaining wall design.
In this example the structural design of the three retaining wall components is performed by hand.
Sketches of the retaining wall forces should be considered to properly distinguish the different forces acting on our retaining wall as tackled in the previous article retaining wall.
Forces on retaining walls 6.
The rocla massbloc instant wall system is comprised of large permeable precast concrete blocks for various retaining applications for walls typically 2 8 metres in height.
The stem may have constant thickness along the length or may be tapered based on economic and construction criteria.
Counterfort retaining walls are more economical than cantilever walls for heights above 25 ft.
P w due to active pressure surcharge wall self weight 1 wall self weight 2 weight of soil wall friction ia m 0 5 x 0 242 x 18 x 2.
Building codes and retaining walls 5.
Construction is mortar less and an experienced crew can place up to 80m2 of wall per day.
Based on our example in figure a 1 we have the forces due to soil pressure due to water and surcharge load to consider.
Two equations are developed.
Design procedure overview 3.
The no fines mix aids resistance to shearing by increasing friction between units and the permeability helps to relieve hydrostatic pressure build up behind the wall.
Both proprietary block and crib retaining walls must be built on an in situ concrete foundation or on a compacted base course.
Because of their large mass.
Ncma tek national concrete masonry association an information series from the national authority on concrete masonry technology concrete masonry gravity retaining wallstek 15 6 structural 1995 keywords.
F c 3000 psi fy 60 ksi natural soil development of structural design equations.
Earthquake seismic design 7.
The graviti block retaining wall system comprises large precast permeable mass concrete blocks manufactured under stringent quality control.
Gravity poured concrete retaining walls.
The base is divided into two parts the heel and toe.
The blocks are interlocked by a key joint precast into the blocks.
Reinforced concrete cantilever retaining wall analysis and design aci 318 14 reinforced concrete cantilever retaining walls consist of a relatively thin stem and a base slab.
Another type of gravity wall is the crib retaining wall which comprises a system of interlocking header and stretcher blocks to retain the granular fill that provides the mass to the wall.
They are generally economical up to 10 feet in height for cast concrete structures.
Retaining wall design 10 editionth a design guide for earth retaining structures contents at a glance.
Allowable stress design lateral loads plain concrete masonry retaining wall unreinforced concrete masonry designed to resist sliding by using reinforcement.
Design tanδ tan 20º or 0 75xdesign tanφ 0 364 or 0 503 design tanδ 0 364 from table design φ 33 8º design δ 20º ka 0 242 10kn m surcharge on retained soil behind wall.
Gravity retaining walls depend on their own weight and any soil resting on the concrete in resisting lateral earth forces.
