thrust plane (thrust plan)

In geol., a type of reversed fault where, as the result of enormous tangential pre ure, the rocks on the upper side of the fault have been pushed or thrust for a greater or le distance, with an entire severance of continuity, over the under The line of junction of the di evered parts in such cases is denominated a thrust-plane. There is one thrust at your pure, pretended mechanism. Dr. H. More, Divine Dialogues. 3. In mech., the stre which acts between two contiguous bodies, or parts of a body, when each pushes the other from itself. A thrust tends Thrust in Medieval Pointed Vaulting. The section in plan is taken at the level of the head of the flying buttre . The arrows indicate the directions of the thrusts. to compre or shorten each body on which it acts in the direction of its action. 4. In coal- mining, a crushing of the pillars caused by exce of weight of the superincumbent rocks, the floor being harder than the roof. It is nearly the same as creep, except that in the latter the workings are disorganized by the upheaval of the floor, which, being softer than the roof, is first to yield to the pre ure. 5. The white whey which is the last to leave the curd under pre ure. E. H. Knight.-Line of thrust. If a straight line be drawn through each bed joint in the ring of an arch so as to represent the position and direction of the resultant pre ure at that joint, a curve drawn so as to touch each of these lines at its intersection with the joint from which it is derived is the line of thrust of the arch. If the arch is stable its line of thrust must lie within the middle third of the depth of the arch-ring. - Thrust of an arch, the force exerted in an outward direction by an arch, and explained by considering its separate stones or vou oirs as so many wedges. Its tendency is to overturn the abutments or walls from which the arch springs, and to deform and ultimately destroy the arch by causing it to break and rise at its haunches. Hence all arches require to be secured in some way against this force, as by the ma of the abutments (the Roman method), by a system of buttre es (the medieval method), or by ties (the Italian method). Also called push of an arch. thrust2, n. thirst. An obsolete or dialectal form of