This　paper　investigates　the　load-bearing　properties　and　failure　mechanisms　of　shield　segments　with　a　circular　mid-span　opening　in　shield　subway　tunnels.　Two　full-scale　specimens　with　opening　diameters　of　100　and　200　mm　were　manufactured　and　tested,　revealing　that　with　an　increasing　opening　diameter,　the　failure　mode　transferred　from　uniform　tensile　fracture　of　inner　arc　concrete　to　the　peeling　and　crushing　of　the　outer　arc　concrete.　Moreover,　the　loading　process　can　be　divided　into　four　stages,　i.e.　elastic,　plastic　expansion,　failure,　and　ultimate　stages,　and　each　stage　shares　a　critical　load.　Subsequently,　numerical　models　were　established　using　the　elastoplastic　damage　constitutive　of　concrete,　and　its　reliability　is　verified　by　the　experimental　results.　Afterward,　parametric　analysis　was　performed　considering　the　plain　concrete　loss　and　reinforced　concrete　loss.　The　analysis　results　show　that　the　plain　concrete　loss　significantly　weakens　the　cracking　load　of　the　segment,　while　reinforced　concrete　loss　has　the　greatest　impact　on　the　failure　load.　Finally,　a　comparative　analysis　is　conducted　between　the　bearing　characteristics　of　the　local　failure　segment,　standard　shield　segment,　and　the　segment　joint.　Overall,　the　research　results　can　provide　a　theoretical　basis　for　the　field　reinforcement　and　the　safety　assessment　of　local　failed　shield　tunnels.