Tunnel surveying is the process of establishing and maintaining the designed position, direction, and level of a tunnel during construction. Because satellite positioning is normally unavailable below the ground surface, surveyors transfer surface control into the tunnel and extend it using traverses, total stations, gyroscopic orientation, and precise levelling. This paper reviews the main techniques used for tunnel surveying and alignment control, including global navigation satellite systems (GNSS), total stations, gyro-theodolites, laser guidance, and three-dimensional laser scanning. It explains how these methods are combined to guide tunnel boring machines (TBMs), control excavation direction, verify the completed structure, and monitor deformation. The study concludes that an integrated survey approach, supported by regular checks and modern automation, is essential for achieving safe and accurate tunnel construction.

Simab Khan, Abdul Ateeque Azher, Ahan N. Gadpayale, Alfiya Khan, Afreen Ansari, Ashlesha Gawali, Bhavana Meshram, Riya Lute, Alisha Paunikar, Aswad khan, "Tunnel Surveying and Alignment Control Techniques" International Journal of Scientific Research and Engineering Development, V9(5): Page(1954-1957) September - October 2026. ISSN: 2581-7175. www.ijsred.com. Published by Scientific and Academic Research Publishing.