Experience of tunnel construction
The scheme of construction of the Lubertsy plant sewage tunnel in Biryulevo (Moscow) and the set of equipment have been designed by Mosinzhproyekt and carried out by a driveage trust of Moscow. The tunnel was constructed according to the main scheme. Tunneling in unstable ground, carried out with a standard shield and precast reinforced entails environmental problems. Ground settlement is caused by excessive excavation along the tunnel contour, resetting of breasting, and clearance between ground and a lining being constructed under shield protection. The pressures exerted on the pressing ring end face and the forms at concrete mix compaction, were measured with pressure cells during the tunneling. The mechanized set was assembled and tested in the initial excavation of the tunnel. The low reliability and problems with the handling of the complex resulted in a considerable number of delays owing to repair and adjustment work.