Theory of Voussoir Arches

40 tons a₁ abutments arch and load arch ring b₁ c₁ centre line centre of gravity centre of pressure considered construction corresponding crown joint cubic foot cubic ft curve of resistance depth of arch depth of key depth of keystone divisions dotted draw a line drawn edge equal equilibrium polygon find the resultant force diagram formulas gives half arch haunches hence hori horizontal distance horizontal resistances horizontal thrust intrados joints of rupture left springing joint length limit at joint line of resistance line parallel live load locomotive load lower middle third masonry maximum method middle third limit multiplying ordinates parallel to ray piers position resistance passes rise side span spandrel specific gravity straight line stress supposed symmetrical tender load theory tion trapezoid true line upper middle third V₁ vertical component vertical distance voussoir arch weight of arch zoid zontal thrust