PROCESS FOR PRESSURE INJECTION WITH MORTAR THE ANNULAR SPACE BETWEEN TUBBING AND ROCK

摘要

The invention relates to a process during shield driving of a tunnel lined withtubbings for pressure injecting the annular space between tubbing and rock with amortar mixture which is introduced into the interspace from a mortar containerinstalled on the trailer by pumping via hosing and pipes disposed in the shieldcasing. In order to attain rapid stiffening of the mortar, in order to lend it thecapability of fulfilling the purpose of the pressure and thrust-resistant embedding ofthe tubbing pipe, but yet, even after a relatively long standstill, to ensure the abilityto start pumping with manageable pressures, according to the invention to the mortarmixture a thixotroping agent and sandy limestone powder is added in such quantitiesthat a rapid initial shearing strength of up 5 to 10 KN/m[err] is attained after 30 minutesand, after an operational standstill, starting the pumping with a low pressure of up toapproximately 8 bars is ensured.