| dc.description.abstract | Complicated geological conditions, high frequency of faults and shear
zones, and abundant groundwater are the main difficulties in tunneling in
Taiwan. The treatment of cave in hazard due to the large quantity of
groundwater ingression with high pressure is extremely difficult. Cases
study in grouting treatment of geological weak zones with groundwater
ingression in Pinglin Pilot Tunnel at Sta. 39K+074 are reported and evaluated
in this thesis for providing a direction of planning for treatment of water
influx in tunneling.
Corresponding experiences for treatment, data which include
permeability and effective range for grouting in this research are obtained
from two cases, one is the treatment of weak geological area which contains
abundant groundwater with debris flow in the Szeleng Sandstone formation of
Pinglin Pilot Tunnel, another is the recovery method from No.3 Fresh Air
Shaft at the Pinglin Tunnel, the model of grouting treatment for permeable
ability of fissured rock is established for application in similar situations
encountered later on.
Permeability of fissured rock mass is decreasing when embedment depth
is increasing, the permeability is quite dispersing and it is difficult to obtained
an exact value from several test only.
Porosity is the major factor for the planning of injection quantity when
grouting in soil mass, but for the rock mass, which is mainly based on fracture
aperture.
According to the grouting experience in the Pinglin Pilot Tunnel, 3 types
of grouting pattern are suggested based on following procedure, first the
III
treatment flow chart is established, the most suitable time and proper grouting
method are concluded in accordance to in-situ situation, these are provided a
direction of planning for grouting treatment on simulated cases.
When special geological condition is encountered during the tunnel
excavation, the planning of ground improvement method is based on the
consideration of several factors, such as, rock mass characteristics,
hydrological geology, engineering and environment, construction equipments
and materials. The ground improvement is carrying out due to the planning
method and it is alternated according to the in-situ situation. | en_US |