pier cap
pile bent
pile bridge
pile cap
pile pier
pin-connected truss
pin joint
pin packing
pin plate
plain concrete
plastic deformation
plate girder
plug weld
plumb bob
plumb line
pneumatic caisson
pontoon bridge
pony truss
portable bridge
portal bracing
pot bearing
pot holes
Pratt truss
precast concrete
prestressed concrete
priming coat
programmed repair
protective system
punching shear

pack - a steel plate inserted between two others to fill a gap and fit them tightly together; also known as packing

pack rust - rust forming in a restricted place that tends to pack itself into a tight fit as the oxide increases the thickness of the parts

paddleboard - striped, paddle-shaped signs or boards placed on the roadside in front of a narrow bridge as a warning of reduced roadway width

panel - the portion of a truss span between adjacent points of intersection of web and chord members

panel point - the point of intersection of primary web and chord members of a truss

parabolic arch - an arch in which the intrados surface is a segment of a symmetrical parabolic surface (suited to concrete arches)

parabolic truss - a polygonal truss having its top chord and end post vertices coincident with the arc of a parabola, its bottom chord straight and its web system either triangular or quadrangular; also known as a parabolic arched truss

parapet - a low wall along the outmost edge of the roadway of a bridge to protect vehicles and pedestrians

pedestal - concrete or built-up metal member constructed on top of a bridge seat for the purpose of providing a specific bearing seat elevation

pedestal pier - one or more piers built in block-like form that may be connected by an integrally built web between them; when composed of a single, wide block-like form, it is called a wall or solid pier

pedestrian bridge - see FOOT BRIDGE

penetration - when applied to creosoted lumber, the depth to which the surface wood is permeated by the creosote oil; when applied to pile driving; the depth a pile tip is driven into the ground 

pier - a substructure unit that supports the spans of a multi-span superstructure at an intermediate location between its abutments 

pier cap - the topmost portion of a pier which distributes uniformly over the pier the concentrated loads from the bridge 

pile - a shaft-like linear member which carries loads through weak layers of soil to those which are  capable of supporting such loads 

pile bent - a row of driven or placed piles with a pile cap to hold them in their correct positions; see BENT 

pile bridge - a bridge carried on piles or pile bents 

pile cap - the uppermost portion of a pile which acts to secure the piles in position and provides a bridge seat to receive and distribute superstructure loads

pile foundation - a foundation reinforced by driving piles in sufficient number and to a depth adequate to develop the bearing resistance required to support the substructure load

pile pier - see PILE BENT 

piling - general term applied to groupings of piles in a construction. see PILE, SHEET PILES 

pin - a cylindrical bar used to connect 

pin-connected truss  -  a general term applied to a truss of any type having its chord and web members connected at the panel points by pins 

pin joint - a joint in a truss or other frame in which the members are assembled upon a cylindrical pin 

pin packing - an arrangement of truss members on a pin at a pinned joint 

pin plate - a plate rigidly attached upon the end of a member to develop the desired bearing upon a pin or pin-like bearing, and secure additional strength and rigidity in the member 

pintle - a relatively small steel pin  engaging the rocker of an expansion bearing, in a sole plate and masonry plate, thereby preventing translation of the rocker ends 

pipe - a hollow cylinder used for the conveyance of water, gas, steam etc. 

piping - a process of subsurface erosion in which surface runoff flows along the outside of a culvert and with sufficient hydraulic gradient erodes and carries away soil around the culvert 

plain concrete - concrete with no structural reinforcement except light steel to reduce shrinkage and temperature cracking 

plan - drawing that represents the top view of a structure and structure site 

plastic deformation -  deformation of material beyond the elastic range 

plate - a  flat sheet of metal greater than 1/8 inch thick 

plate girder - a large I-shaped beam composed of a solid web plate with flange plates attached to the web plate by flange angles or fillet welds 

plug weld - a weld joining two members produced by depositing weld metal within holes cut through one or more of the members; also known as slot weld 

plumb bob - a weight hanging on a cord used to provide a true vertical reference 

plumb line - a true vertical reference line established using a plumb bob 

pneumatic caisson - a caisson in which the working chamber is kept full of compressed air at a pressure nearly equal to the water pressure outside it 

pointing - the compacting of the mortar in the outermost portion of a joint and the troweling of its exposed surface to secure water tightness or desired architectural effect  

ponding -  water backed up in a channel or ditch as the result of a culvert of inadequate capacity  

pontoon bridge - a bridge which floats on pontoons moored to the riverbed; a portion may be removable to facilitate navigation 

pony truss - a through truss having insufficient height to use a top chord system of lateral bracing  

pop-out - conical fragment broken out of a concrete surface by pressure from reactive aggregate particles usually found at the bottom of the hole 

portable bridge - a bridge that may be readily erected for a temporary communication-transport service disassembled and its members again reassembled and the entire structure rendered ready for further service 

portal - the clear unobstructed space of a through truss bridge forming the entrance to the structure 

portal bracing - a system of sway bracing placed in the plane of the end posts of the trusses 

post - a member resisting compressive stresses, located vertical to the bottom chord of a truss and common to two truss panels; sometimes used synonymously for vertical; see COLUMN 

posted - a limiting dimension, speed, or loading indicating larger dimensions and higher speeds and loads can not be safely taken by the bridge 

post-stressing - see POSTTENSIONING 

posttensioning - a method of externally prestressing concrete in which the tendons are stressed after the concrete has been cast 

pot bearing - a bearing type that allows for multi-dimensional rotation by using a neoprene or spherical bearing element 

pot holes - irregular shaped,disintegrated areas of bridge deck or approach pavement concaved by the failure of the surface material 

Pratt truss - a truss with parallel chords and a web system composed of vertical posts with diagonal ties inclined outward and upward from the bottom chord panel points toward the ends of the truss; also known as N-truss  

precast concrete - concrete members which are cast and cured before being placed into their final positions on a construction site 

prestressed concrete - concrete in which cracking and tensile forces are greatly reduced by compressing it with tensioned  cables or bars  

prestressing - applying forces to a structure to deform it in such a way that it will withstand its working loads more effectively; see POSTTENSIONING, PRETENSIONING 

pretensioning - a method of prestressing concrete in which the cables are held in a stretched condition until the concrete has hardened, then the pull on the cables is released inducing internal compression into the concrete 

priming coat - the first coat of paint applied to the metal or other material of a bridge; also known as base coat, shop coat 

probing - investigating the location and condition of submerged footing foundation material using a rod or shaft of appropriate length; checking the surface condition of a timber member for decay using a pointed instrument, e.g., an ice pick 

profile - a section cut vertically through the center line of a roadway or waterway to show the original and final ground levels 

programmed repair -  those repairs that may be performed in a prescheduled program over the next 2 to 24 months 

protective system - a system used to protect bridges from environmental forces that cause steel and concrete to deteriorate and timber to decay, typically a coating system 

punching shear - shear stress in a slab due to the application of a concentrated load