Ib tug steel truss choj yog ib tug structural system ntawm beams thiab arches. Nws muaj cov dabtsi yog khoov-cov kab hluav taws xob sab sauv (lossis slab) cov qauv sib xyaw ua ke nrog cov khoom thauj -cov kabmob qis qis (lossis pier) qauv. Vim yog kev sib txuas ntawm cov kab teeb thiab cov kab, cov kab teeb yog unloaded los ntawm bending stiffness ntawm cov kab. Tag nrho cov txheej txheem yog compression -bending qauv, thiab kuj yog ib tug thrust qauv. Nws yog ib yam ntawm tus choj uas lub ntsiab load- bearing qauv yog ib tug nruj ncej. Nws ua rau kom qhov siab clearance nyob rau hauv tus choj thiab feem ntau yog siv raws li ib tug overpass.
Raws li daim duab qhia kev quab yuam, nws tuaj yeem muab faib ua qhov ruaj khov- kawg cov ncej nruj, ob npaug -hinged rigid thav duab txuas hniav, thiab peb -hinged rigid ncej choj, thiab lwm yam.; Raws li hom kev nce siab, nws tuaj yeem muab faib ua portal rigid thav duab txuas hniav, ncaj- ceg tawv thav duab txuas hniav, inclined- ceg txhav ncej txuas hniav, V- zoo li tus pier rigid ncej txuas hniav, thiab T- zoo li tus ncej nruj choj, thiab lwm yam.; Raws li tus naj npawb ntawm cov spans, nws tuaj yeem muab faib ua ib zaug - ncua kev txuas txuas txuas txuas thiab ntau- ncua kev txuas txuas txuas, thiab lwm yam; Raws li seb puas muaj kev txhawb nqa kab rov tav, nws tuaj yeem muab faib ua thrust{12}}txhawb cov ncej txuas hniav thiab thrust-dawb rigid ncej txuas hniav, thiab lwm yam.
Hom choj no muaj lub sijhawm tsis zoo dabtsi yog khoov ntawm cov nodes, uas txo qhov zoo dabtsi yog khoov lub sijhawm ntawm nruab nrab - ncua ntawm lintel. Nws muaj qhov siab me me, ua rau nws zoo - haum rau cov hla hla thiab cov choj siab siab, thiab nws kuj txuag cov khoom siv. Nyob rau hauv sib piv, cov lintels thiab txhua kab ntawm reinforced pob zeb rigid ncej txuas hniav feem ntau yuav tsum tau cam khwb cia integrally nyob rau hauv situ, uas ua rau ib tug tsawg℃ntawm prefabrication. Nyob rau hauv ntsug loads, hom choj no tsim kab rov tav thrust ntawm kab hauv paus, tso siab xav tau ntawm lub hauv paus.