پاورپوینت ارزيابی كيفيت اجرایی ماشين های حفاری قابل ویرایش 27 اسلاید Solution for increasing of performance: • Change in material and design of bits. • Improve the machine design. • Improve the cutterhead design. • Case study in Turkey • The Hereke Tunnel, located in Turkey in the city of Ko