The　excavation　disturbed　zone　plays　an　important　role　in　the　evaluation　of　tunnel　stability.　The　identification　of　the　excavation　disturbed　zone　is　perceived　as　a　main　concern.　Taking　the　material　meso-structure　into　account,　this　paper　investigates　the　construction　mechanical　behavior　in　heterogeneous　sand　cobble　stratum　and　aims　to　precisely　predict　the　excavation　disturbed　zone.　Firstly,　the　meso-scale　numerical　models　were　used　to　simulate　tunnel　excavation　in　sandy　cobble　strata,　in　which　the　large-sized　rock　blocks　and　fine-grained　soil　matrix　were　treated　as　separate　constituents.　Then,　the　stress　redistribution　and　deformation　performance　in　the　ground　during　tunneling　were　explored　in　detail.　Subsequently,　combined　with　the　deformation　performance　characteristics,　a　method　for　identifying　the　excavation　disturbed　zone　was　proposed.　The　boundary　of　the　excavation　disturbed　zone　can　be　identified　by　the　displacement　mutation　point　of　the　monitoring　paths.　Finally,　a　parametric　study　was　performed　to　understand　the　influence　of　key　factors　on　the　excavation　disturbed　zone,　including　the　rock　meso-structure　parameters,　the　soil　matrix　properties,　and　the　tunnel　geometry　characteristics.　The　simulation　results　indicate　that　both　the　rock　content　and　rock　size　have　a　significant　impact　on　the　excavation　disturbed　zone,　the　strength　parameters　and　lateral　pressure　coefficient　have　a　marked　effect,　and　the　tunnel　radius　and　tunnel　burial　depth　have　a　negligible　influence　on　the　excavation　disturbed　zone　under　the　given　conditions　when　normalized.