For　the　purpose　of　identifying　the　rock　mass　conditions　of　the　tunnel　face　and　determining　the　TBM　operating　parameters,　real-time　monitoring　of　TBM　cutter　forces　is　required.　For　a　TBM　cutter　mounted　in　the　cutter　box　with　a　fixed　wedge　block,　a　cutter　force　measurement　system　is　proposed　to　measure　the　cutter　forces　in　the　laboratory.　The　C-shaped　block　in　the　cutter　box　was　replaced　by　a　designed　C-shaped　block　sensor　as　the　force　measurement　component.　By　optimizing　the　structure　of　the　C-shaped　block　sensor,　a　bi-directional　force　sensor　with　two　full-bridge　circuits　on　the　bottom　and　side　of　the　C-shaped　block　was　built.　The　cutter　force　measurement　system　consists　of　two　C-shaped　bi-directional　force　sensors　to　measure　the　normal　force,　rolling　force　and　side　force　of　the　cutter.　The　results　of　laboratory　calibration　experiments　show　that　the　cutter　force　measurement　system　is　capable　of　measuring　the　cutter　forces　under　various　working　conditions,　and　the　linearity　of　the　system　is　about　10　%　for　the　overall　force　measurement.　In　general,　the　cutter　force　measurement　system　built　with　C-shaped　force　sensors　has　the　advantages　of　accurate　measurement,　simple　installation　and　stable　operation.　The　system　has　great　prospects　for　application　in　TBM　tunneling.　©　2024