Lots of fault treatment programmes
Tunnel through faults location, the construction difficulty depends on the nature of the fault, the fault broken zone width, fill, axes and water and fault activity and tunnel combination relationship of fault line direction (orthogonal, oblique, or parallel). In addition, and the degree of damage to the surrounding rock during construction, process of convergence speed, technical measures for the construction of the propriety, have a great relationship.
When the tunnel axis close to the vertical construction line directions, small size of the fault, fracture zone is not wide, and when the water with smaller, more favourable conditions, with the dig with the pole. But when when you skew or parallel to the construction of tunnel axis direction, then the length of the tunnel through fractured zone increases and strong lateral pressure, should strengthen the arch lining of walls, closed in a timely manner.
Reasonable selection of construction methods:
Band 1, fault gouge or a special loose of filling of soft plastic particles, mutatis mutandis, in loose formation of advanced support, with arch your back wall where special broken fault zone, you may use the horses mouth excavation.
2 lots having large amounts of water, such as fault, then the row blocking the combination of control measures should be taken.
When 1, such as faults in groundwater from surface water supplies, should set the cutting surface introduction drainage system. On fault of confined water, should be in each driving cycle, forward direction drill to tunnel not less than 2 advanced drilling, their should be more than 4 meters in depth, to detect groundwater situations.
2, with working face excavation digging of drains, prepare adequate pumping equipment, and arrange for the appropriate set of puddles.
3, through the fault of the distance between the construction process should be as short as possible and closed as soon as possible lining, to reduce the exposure of surrounding rocks, loose and pressure increases.
4, in the tunnel in fault location, the low-down on drilling and blasting design for special. Strict control of all holes in particular around the eye, depth and number of charge, to minimize the disturbance of surrounding rock blasting in principle.
5, excavation of the fault zone should be carried out immediately after the first jet concrete and insisted “in ningqiang County not weak” principle, strengthening the support.
6, followed by on-site excavation surface measurement, depending on the measurement of the feedback information timely adjustment of parameters of early support and the best time to master the secondary lining.
Second, the tunnel water treatment schemes
1, when water volume is not, using block-row combination of methods, namely strengthening the arch lining the walls, in the arch lining of permeable hose blind ditch and wall thickness peripherals connected, diversion to the both sides of the tunnel gully water; in the arch wall lining seam located vertically waterstop.
2, in order to prevent the occurrence of exceptions such as water, on water inrush phenomenon more serious I group mature lot intended to be used is based on the technology of splitting Grouting comprehensive treatment technology, that is, splitting Grouting consolidation method construction.
(1) the process splitting Grouting consolidation method construction process flow is as follows:
(2) method of construction
(A) by geological drilling information analysis fault geology.
(B) design of bored grouting and lining of tunnel.
(C) prepare for grouting material, determination of performance.
(D) drilling and Grouting machinery and equipment for installation and commissioning.
B) occluding rock disc or Grouting wall in general more complete rock top 5m as the occluding batholith. If bedrock joint development, rock crushing 2~5m should be set when the occluding wall, surrounding rock 0.3~0.5m and embed the wall. C) drill (a) laying of orifice tube: hole diameter for PHI 146mm, length 2m, CS (cement, water glass) mortar laid 127mm orifice tube, spout installation 127mm spherical valves, as closed may appear in the drilling of water.
(B) drilling diameter using φ 108mm, when the drill to the latter part, drilling diameter to 89mm. XU-3002A selection of drill drilling machinery and YGZ-100 guide rail type independently rotating drilling machine.
(C) chipping when drilling, observation and analysis of backwater core or to abandon the ballast condition, to judge the quality of Grouting and adjust the parameters of Grouting.
(D) drilling sequence:
D) water injection test
(A) hole injection after a few minutes (Note water from small to large), absorption of water, and clean the rock fractured.
(B) put in the connectivity test materials, plus water, as the connectivity test.
E) Grouting method
(A) double liquid Grouting system
(B) of Grouting under borehole geology, may use full Grouting with hole Grouting method-and-forward, backward segment. In the process of construction, in case of fault development may occur when water, using advanced segmentation drilling and grouting, gradually move forward wall.
(C) principle of drilling and Grouting in the drilling and Grouting principle is outside your back, first thinning back key, foreign key and repeatedly note, open hole drilling induced.
(D) type of Grouting type of Grouting into cement and cement-water glass two-liquor, under design, water injection test of Grouting and cleaning hole, pumping capacity in inlet mud grouting process identified with single or dual liquid.
(E) Grouting completes reach the Grouting pressure values as required, and should be regulated for 30 minutes.
(F) when grout of excavation and lining Grouting completes after 8 hours, you can make the tunnel. Arch after arch wall lining a first wall or by continuous infusion method.
3) main mechanical equipment of a jobs main
4) construction measures
(1) quality control
A) manholes sampling checks should be carried out. Testing compressive strength of solid composition, pulse permeability and consolidation in pulp quality.
B) inspection hole water infusion test, that is, before and after Grouting water injection rate comparison.
C) determination of permeability and consolidation of Grouting State.
D) in the implementation of the Grouting of the abnormal situation analysis and treatment measures.
A) Grouting required of workers equipped with supplies of labour protection, such as masks, glasses, long gloves and rubber gloves.
B) if the eyes, face or skin contact when the slurry, immediately flush thoroughly with water or saline solution, serious host.
C) mechanical and electrical equipment safety shield and earth leakage protective device should be set.
D) change by rotation as of rail-tires or parts of machinery when the drill pipe, pay attention to wounding by high pressure mud and water rushed out of the hole.
E) drilling if it occurs in water, take measures should concentrate, grouting and sealing in a timely manner.
F) strengthen the unity of command, coordination, to ensure safe production.