Description
Shield foaming agent has high foaming rate, bubble uniform and high
stability, which are guarantees that the earth pressure balance
shield machine and take necessary for the smooth construction of
the shield products. The products applicable to rock and soil
tunnel engineering of soil, its performance is better than the
other similar products. 1. Application of foaming agent in shield
tunneling construction It is composed of numerous small bubbles
mixed into the muck, Often referred to as the injection is injected
into the bubble. The bubble is a typical gas *- liquid two-phase
system, is more than *0%, less than *0% of the foaming solution.
And foaming solution *2%**8.5% water. The rest of the foaming agent
and the raw liquor. Foam injection of excavation face, support or
screw conveyor, the excavation soil is plastic flow through the use
of fruit surface paste Micro Foam lubrication. When it is subjected
to strong mixing, fine bubbles and excavation soil mixing, and
subsequently replacement of soil particles in pore water, foam
generated from andimprove the sealing property. From in head
chamber of shield machine after discharge encountered decompression
will break itself, without adding foaming agent. 2. The product
uses and Applications 1ã€Shield foam is suitable for rock and
soil, gravel soil, silty soil, with fine foam, has the following
properties: 1. To reduce mechanical wear of the shield machine.
Earth pressure balance is shield machine in the friction of the
larger soil excavation, and the soil occurred in the role of
cutting tool wear easily. Therefore, the injection foam on the
cutter can reduce soil friction, reduces the cutting tool, cutter
and shield abrasion. 2. Adjustment values of soil plastic flow.
Earth pressure balanced shield tunneling process, soil nature, will
directly affect the smooth excavation of shield machine, if after
cutting the muck has good plasticity and fluidity, not only can the
excavation face maintain good support pressure and guarantee the
smooth implementation of soil drainage. Furthermore, in shield
tunneling, due to changes in the formation, not after processing
into the soil of the earth are usually easy to within the chamber
occurs "cake", "blocked" and problems, seriously affect the
tunneling efficiency. Foam occupancy can effectively solve the
problem. 3. Reduce the permeability of the sediment, soil pressure
balance type purchase in the gravel layer through the layer of
foundation construction, excavation face high water
pressure will cause of purchase screw conveyor export groundwater
occurrence loss of a large number of, severe will spew. Driving
effect smoothly into foam can effectively reduce the permeability
of the muck, effectively prevent occurrence of tunneling spewing.
4. Reduce cutting muck of internal friction force and reduce
cutter, screw conveyor wear and reduce knife wheel torque to
prevent the machine energy consumption high fever and failure. 5.
In the rock tunnel and mine in the dust inhibitor. 6. Improve the
safety of construction work on the surrounding ecological
environment pollution.
