Voussoir Arches Applied to Stone Bridges, Tunnels, Domes and Groined Arches

abutment acting actual line arch ring assumed bridge center line center of gravity center of pressure cloth column combined compressed edge construction crown joint crown to joint cubic culvert curve of pressures deformation depth of arch depth of keystone distance dome draw drawn earth edges of joints Engineer equal exerted extrados feet force diagram formulæ groin haunches hori horizontal forces horizontal resistances increase the depth inner third intersection intrados joint of rupture joints open lever arm limit at joint line of pressures load lower middle third lune solid middle third limit NOSTRAND'S numbers pier radius Rankine's resultant on joint segmental bridge side simple arch soffit span spandrel thrust springing joint square foot strain summit supposed surface tangent tensile resistances theory thickness tion tons total horizontal thrust trapezoid true curve tunnel arch upper middle third ures voussoir arch weight whence width