AU2021101943A4 - A construction control method for a subway shield to penetrate through existing buildings - Google Patents
A construction control method for a subway shield to penetrate through existing buildings Download PDFInfo
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- AU2021101943A4 AU2021101943A4 AU2021101943A AU2021101943A AU2021101943A4 AU 2021101943 A4 AU2021101943 A4 AU 2021101943A4 AU 2021101943 A AU2021101943 A AU 2021101943A AU 2021101943 A AU2021101943 A AU 2021101943A AU 2021101943 A4 AU2021101943 A4 AU 2021101943A4
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- existing buildings
- control method
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- 238000010276 construction Methods 0.000 title claims abstract description 72
- 238000000034 method Methods 0.000 title claims abstract description 46
- 239000002689 soil Substances 0.000 claims abstract description 36
- 230000002787 reinforcement Effects 0.000 claims abstract description 17
- 230000007613 environmental effect Effects 0.000 claims abstract description 14
- 238000001514 detection method Methods 0.000 claims abstract description 6
- 239000000126 substance Substances 0.000 claims abstract description 6
- 230000005641 tunneling Effects 0.000 claims description 24
- 239000002002 slurry Substances 0.000 claims description 19
- 230000001360 synchronised effect Effects 0.000 claims description 12
- 238000012360 testing method Methods 0.000 claims description 9
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 claims description 8
- 238000009412 basement excavation Methods 0.000 claims description 6
- 239000007788 liquid Substances 0.000 claims description 6
- 230000008569 process Effects 0.000 claims description 6
- 239000000463 material Substances 0.000 claims description 5
- 239000000440 bentonite Substances 0.000 claims description 4
- 229910000278 bentonite Inorganic materials 0.000 claims description 4
- SVPXDRXYRYOSEX-UHFFFAOYSA-N bentoquatam Chemical compound O.O=[Si]=O.O=[Al]O[Al]=O SVPXDRXYRYOSEX-UHFFFAOYSA-N 0.000 claims description 4
- 238000005553 drilling Methods 0.000 claims description 4
- 238000006073 displacement reaction Methods 0.000 claims description 3
- 239000004088 foaming agent Substances 0.000 claims description 3
- 238000007599 discharging Methods 0.000 claims description 2
- 230000002411 adverse Effects 0.000 abstract description 3
- 238000012544 monitoring process Methods 0.000 description 12
- 239000004568 cement Substances 0.000 description 6
- 230000000694 effects Effects 0.000 description 6
- 238000011161 development Methods 0.000 description 4
- 238000013461 design Methods 0.000 description 3
- 238000002347 injection Methods 0.000 description 3
- 239000007924 injection Substances 0.000 description 3
- 239000004215 Carbon black (E152) Substances 0.000 description 2
- 239000004115 Sodium Silicate Substances 0.000 description 2
- 230000008859 change Effects 0.000 description 2
- 230000007423 decrease Effects 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 239000011440 grout Substances 0.000 description 2
- 229930195733 hydrocarbon Natural products 0.000 description 2
- 150000002430 hydrocarbons Chemical class 0.000 description 2
- 238000011835 investigation Methods 0.000 description 2
- 238000005259 measurement Methods 0.000 description 2
- 238000011160 research Methods 0.000 description 2
- 238000004088 simulation Methods 0.000 description 2
- NTHWMYGWWRZVTN-UHFFFAOYSA-N sodium silicate Chemical compound [Na+].[Na+].[O-][Si]([O-])=O NTHWMYGWWRZVTN-UHFFFAOYSA-N 0.000 description 2
- 229910052911 sodium silicate Inorganic materials 0.000 description 2
- 230000003245 working effect Effects 0.000 description 2
- 206010034719 Personality change Diseases 0.000 description 1
- 239000011398 Portland cement Substances 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- 230000009286 beneficial effect Effects 0.000 description 1
- 230000001186 cumulative effect Effects 0.000 description 1
- 238000009792 diffusion process Methods 0.000 description 1
- 238000005315 distribution function Methods 0.000 description 1
- 239000010881 fly ash Substances 0.000 description 1
- 230000006872 improvement Effects 0.000 description 1
- 238000009440 infrastructure construction Methods 0.000 description 1
- 230000001788 irregular Effects 0.000 description 1
- 230000002045 lasting effect Effects 0.000 description 1
- 239000000203 mixture Substances 0.000 description 1
- 230000035699 permeability Effects 0.000 description 1
- 230000003014 reinforcing effect Effects 0.000 description 1
- 239000004576 sand Substances 0.000 description 1
- 239000002893 slag Substances 0.000 description 1
- 230000003068 static effect Effects 0.000 description 1
Classifications
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/06—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D11/00—Lining tunnels, galleries or other underground cavities, e.g. large underground chambers; Linings therefor; Making such linings in situ, e.g. by assembling
- E21D11/003—Linings or provisions thereon, specially adapted for traffic tunnels, e.g. with built-in cleaning devices
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/001—Improving soil or rock, e.g. by freezing; Injections
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/14—Layout of tunnels or galleries; Constructional features of tunnels or galleries, not otherwise provided for, e.g. portals, day-light attenuation at tunnel openings
-
- E—FIXED CONSTRUCTIONS
- E21—EARTH OR ROCK DRILLING; MINING
- E21D—SHAFTS; TUNNELS; GALLERIES; LARGE UNDERGROUND CHAMBERS
- E21D9/00—Tunnels or galleries, with or without linings; Methods or apparatus for making thereof; Layout of tunnels or galleries
- E21D9/001—Improving soil or rock, e.g. by freezing; Injections
- E21D9/002—Injection methods characterised by the chemical composition used
Landscapes
- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Geochemistry & Mineralogy (AREA)
- Geology (AREA)
- Environmental & Geological Engineering (AREA)
- Architecture (AREA)
- Civil Engineering (AREA)
- Structural Engineering (AREA)
- Soil Sciences (AREA)
- Excavating Of Shafts Or Tunnels (AREA)
Abstract
The invention discloses a construction control method for a subway shield to penetrate
through existing buildings, which comprises the following steps: Si. Acquiring shield
construction conditions based on environmental information of the existing building; S2.
Determining the coring position of the existing building according to the environmental
information in step SI; S3. Carrying out hole exploration according to the core position to
obtain the soil sample, and detecting whether the soil sample contain combustible substances
or not. If not, proceed to S4; if yes, return to Sl; S4. Carrying out shield machine construction
according to the detection result of S3 and shield construction conditions, controlling the
construction parameters and the posture of the shield machine, so as to improve the ballast soil,
and grouting on the surface for reinforcement. The invention effectively reduces the occurrence
of geological subsidence, while it does not adversely affect the existing buildings during the
construction of the shield underpass, therefore the safety and integrity of existing buildings can
be ensured.
1/3
FIGURES
Sl Acquiring shield construction conditions based on environmental information of the
existing building
Determining the coring position of the existing building according to the environmental
information in step SI
Carrying out hole exploration according to the core position to obtain the soil sample, and
detecting whether the soil sample contain combustible substances or not. If not, proceed
to S4; if yes, return to SI
Carrying out shield machine construction according to the detection result of S3 and shield
construction conditions, controlling the construction parameters and the posture of the
shield machine, so as to improve the ballast soil, and grouting on the surface for
reinforcement
Figure 1. The schematic flow chart of the construction control method for subway
shield passing through existing buildings
Description
1/3
Sl Acquiring shield construction conditions based on environmental information of the existing building
Determining the coring position of the existing building according to the environmental information in step SI
Carrying out hole exploration according to the core position to obtain the soil sample, and detecting whether the soil sample contain combustible substances or not. If not, proceed to S4; if yes, return to SI
Carrying out shield machine construction according to the detection result of S3 and shield construction conditions, controlling the construction parameters and the posture of the shield machine, so as to improve the ballast soil, and grouting on the surface for reinforcement
Figure 1. The schematic flow chart of the construction control method for subway
shield passing through existing buildings
A construction control method for a subway shield to penetrate through existing
buildings
The invention relates to the technical field of subway shield construction, in particular
to a construction control method for a subway shield to penetrate through existing buildings.
In order to meet the needs of the rapid development of urban transportation, large
cities in China and abroad are carrying out subway construction. In the 21st century, with
the rapid economic development and strategic requirements, the world has entered the
period of rapid development of urban infrastructure construction, especially the subway
project construction. Based on the experience of metro engineering in China and abroad,
the technical difficulties in construction are mainly focused on the adaptability of metro
construction to stratum conditions, the influence of construction on surrounding
environment and the internal influence in the process of engineering implementation. At
present, there are many research results in China and abroad, and its development trend
will be toward the direction of higher environmental protection requirements and greater
complexity. Because the subway is not only used for transportation, its function is
becoming more and more expanded, and the planning is more profound, the subway
engineering construction also faces the trend of more diversified and comprehensive
engineering problems.
Although the shield method has been widely used in subway construction because of
its high degree of mechanization and strong adaptability, the shield construction still causes the deformation of the overlying soil layer, and the adverse effects caused by the shield tunneling through existing tunnels and pipelines, railways, buildings and bridge piers have become one of the hot spots. Many scholars at home and abroad have carried out a lot of research on the problem of shield construction crossing: Peck first proposed the concept of ground loss in 1969 and suggested the Gauss distribution function (i.e. Peck's formula) to describe the ground settlement caused by shield construction; some scholars have studied the effect of settlement caused by shield tunnel crossing existing metro stations under oblique intersections; some experts have studied the effect of shield tunnel excavation in soft soil areas on the working properties of bearing piles, and analysed the control of surface and pile deformation by two different reinforcement methods; other studies include the effect of oversized diameter shield tunnel crossing on the ground settlement of protected building complexes, and the control of ground deformation by large reinforcement methods. Some experts have studied the effect of shield tunnel excavation on the working properties of bearing pile foundations in soft soil areas and analysed the control of surface and pile deformation by two different reinforcement methods; other studies include the ground settlement pattern of a large diameter shield under a protected building complex, the prediction of building settlement using numerical simulation and comparison with engineering monitoring data on the construction of a large diameter earth pressure balance shield through a building, and the collection of bridge piles and ground settlement on the side of a shield through a bridge as an example. The settlement change data of bridge piles and ground surface were collected and combined with the shield advance soil pressure and grouting volume to analyse the settlement deformation of bridge piles and the ground surface around the bridge at different stages, etc.
Many cities in the world are typical urban villages, and the buildings of private houses
are extremely irregular, and there are quality problems in private houses. The phenomenon
of privately built houses and raised buildings is also common. Besides private houses, there
are underground liquid storage facilities, such as underground oil storage tanks of gas
stations. When the subway passes through existing buildings, there is a great construction
safety risk. Therefore, there is an urgent need for a control method for subway shield to
pass through the liquid storage facilities.
The purpose of the present invention is to provide a construction control method for
subway shield passing through existing buildings, so as to solve the problems existing in
the prior art. In this way, the settlement of existing buildings can be effectively reduced
and the safety integrity of existing buildings can be ensured when the shield machine is
adopted in subway construction.
In order to achieve the above purpose, the invention provides the following scheme:
the invention provides a construction control method for a subway shield passing under an
existing building, including the following steps;
Si. Acquiring shield construction conditions based on environmental information of
the existing building;
S2. Determining the coring position of the existing building according to the
environmental information in step Sl;
S3. Carrying out hole exploration according to the core position to obtain the soil
sample, and detecting whether the soil sample contain combustible substances or not. If
not, proceed to S4; if yes, return to Sl;
S4. Carrying out shield machine construction according to the detection result of S3
and shield construction conditions, controlling the construction parameters and the posture
of the shield machine, so as to improve the ballast soil, and grouting on the surface for
reinforcement.
Preferably, the environmental information of Si existing buildings includes the
number, arrangement, buried depth, volume, height, width, wall thickness and material of
the existing buildings.
Furthermore, S3 adopts manual hole digging method for coring.
Further, in S4, double track tunneling is adopted for shield tunneling.
Preferably, the double-line tunneling method comprises the following steps:
performing one-line tunneling firstly, and performing the other-line tunneling after
completion of the former.
In addition, the construction parameters of shield machine in S4 include tunneling
parameters, synchronous grouting parameters and secondary grouting parameters.
The tunneling parameters comprise thrust, propulsion speed, cutter head rotating
speed, earth bin pressure, cutter head torque and excavated volume.
The grouting amount of the synchronous grouting is 1.3-1.8 times the annular gap
volume, 3.5-4.5 m3/ring grouting amount and 0.2-0.3 MPa;
The secondary grouting pressure is 0.01-0.03 MPa higher than the synchronous
grouting pressure, and the secondary grouting adopts a grouting pipe with a check valve.
In S4, the surface grouting reinforcement adopts a sleeve valve tube reinforcement
method.
In S4, the method of improving ballast soil is to adjust the amount of foaming agent and bentonite in the process of shield machine excavation based on the speed of excavation, the torque of the cutter head and the condition of ballast discharging.
The sleeve valve tube reinforcement method comprises the following steps:
Drilling the grouting hole and injecting water into the grouting hole to test the internal
pressure of the grouting hole;
The grouting slurry shall be pumped into the grouting hole after the internal pressure
test of the grouting hole passes;
When grouting, the pressure is gradually reduced from low to high, and the
displacement is gradually reduced and balanced, which is normal . Otherwise, the slurry
ratio is changed or the gel time is adjusted.
After each grouting hole reaches the final pressure, and the grouting amount of single
liquid slurry is less than 20-30 litres/min, after stable for 20-30 minutes, the grouting is
finished.
Beneficial effects:
The invention adopts the form of splitting the double line construction into single line
construction in sequence, by controlling the construction parameters and attitude of the
said shield machine, it improves the composition of the ballast soil and reinforcing the
ground with slurry, which effectively reduces the occurrence of geological subsidence and
does not adversely affect the existing buildings during the construction of the shield
underpass, ensuring the safety and integrity of existing buildings.
In order to explain the embodiments of the present invention or the technical scheme
in the prior art more clearly, the drawings needed in the embodiments will be briefly introduced below. Obviously, the drawings in the following description are only some embodiments of the present invention, and for ordinary technicians in the field, other drawings can be obtained according to these drawings without paying creative labor.
Figure 1 is the schematic flow chart of the construction control method for subway
shield passing through existing buildings;
Figure 2 shows the schematic diagram of the settlement time course curve of the
ground measurement points in the embodiment of the invention;
Figure 3 is the schematic diagram of the settlement time course curve of the measured
points of the building (structure) in the embodiment of the present invention.
The technical scheme in the embodiments of the present invention will be described
clearly and completely with reference to the drawings in the embodiments of the present
invention. Obviously, the described embodiments are only part of the embodiments of the
present invention, not all of them. Based on the embodiments of the present invention, all
other embodiments obtained by ordinary technicians in the field without creative labor
belong to the scope of protection of the present invention.
In order to make the above objects, features and advantages of the present invention
more obvious and easy to understand, the present invention will be further explained in
detail with reference to the accompanying drawings and specific embodiments.
With reference to Figure 1, this embodiment provides a construction control method
for subway shield passing through existing buildings by taking a gas station during subway
construction in a city of a country as an example, which specifically includes the following
steps:
Si. Investigation of the the environmental information of existing buildings to obtain
the shield construction conditions.
Taking the gas station in this embodiment as an example, there are three buried oil
storage tanks arranged in parallel at the gas station, with the center distance of 5.Om and
the same size, all with a volume of 50m3 . The shape can be simplified as an axisymmetric
structure with hemispheres at both ends and a cylinder in the middle. The total length of
the tank is 9.25m, the inner diameter is 1.4m, the cylinder wall thickness is 8.0mm, the
head wall thickness is 10.0mm, and the distance between the center of the oil storage tank
and the surface is 4.0m (the net distance between the oil storage tank and the surface is
2.52m).
S2. Determination of the the coring position of the existing building according to the
investigation result of SI.
S3. According to the coring position to obtain a soil sample for detecting whether
there are combustible substances in the soil sample.
In this method, five hole positions are drilled by manual drilling tool, each hole
spacing is 4.5 m, and the distance of the hole edge line is 1000000 and the construction
depth of each hole is 10000000.The test structure shows that there is no oil hydrocarbon in
the soil sample, and if no hydrocarbon is detected, the shield machine is ready for tunneling.
S4. Carrying out shield machine construction according to the detection result of S3
and shield construction conditions, controlling the construction parameters and the posture
of the shield machine, so as to improve the ballast soil, and grouting on the surface for
reinforcement.
In this method, the shield machine is driven by double-line construction method.
However, in order to reduce the influence of the disturbance of the shield machine's left
and right lines on the gas station caused by the disturbance of soil surface subsidence, the
shield construction plan is adjusted, the left line is driven first, and the right line is started
after the left line shield machine passes through the gas station smoothly. The time interval
is about 12d, which can guarantee the grouting reinforcement effect of the left line soil,
which can reduce the interference and influence between the two shield structures, and
finally effectively control the influence of the two shield machines on the ground at the
same time.
In the course of shield machine driving, the shield machine adjusts the adding amount
of foaming agent and bentonite in time according to the speed of driving, the torque of the
cutter head and the condition of ballasting, so as to ensure the good fluidity and plasticity,
suitable consistency, low water permeability and small friction resistance of the shield
cutting slag, so as to ensure the stability of the soil in the cabin pressure and the front of
the cutter head, and the density of the ballast is basically consistent reduce the loss of tools
and other equipment and control the subsidence of the surface.
In order to ensure the quality of shield tunneling, it is necessary to control the
engineering parameters and shield posture during tunneling. Among them, the engineering
parameters include tunneling parameters, synchronous grouting parameters and secondary
grouting parameters, and the detail is as follows:
In this method, the driving parameters: the thrust control of shield machine is within
10000-15000 KN when driving through the gas station, and the driving speed of shield
machine directly affects the settlement of soil, so the driving speed of shield machine
should be slowed down when passing through the gas station, so as to minimize the disturbance to the soil mass, so the driving speed should be controlled at 30-50 mm/min, and the blade speed of 0.8-1.0 r/min, the pressure of the soil bin shall be controlled within
0.08-0.1 MPa cutter head torque of 2500-2800 knm and the excavated quantity shall be
controlled within 47 m3
. During synchronous grouting, in order to ensure the effective filling of the annular
gap and ensure that the segment structure is not deformed and damaged by grouting, the
synchronous grouting quantity is 1.3 ~ 1.8 times of the theoretical volume of the annular
gap, so that the grouting quantity Q of each ring is 3.5 ~ 4.5 m3 and the grouting pressure
is 0.2 ~ 0.3 MPa. The ratio of synchronous grouting slurry in this embodiment: water:
cement: sand: fly ash: bentonite = 7.6: 1: 17.8: 8: 1.6; ; Synchronous grouting requires that
the pressure at the pressure inlet is greater than the sum of static water pressure and earth
pressure at this point, so as to fill as much as possible instead of splitting.
During secondary grouting, special lining rings (grouting holes are added) are set in
the section passing through the gas station, and secondary grouting is strengthened (the
scope of grouting holes is added). The secondary grouting starts from the 4th ring behind
the shield tail, and the secondary pressure is 0.01 ~ 0.03 MPa higher than the synchronous
grouting pressure. In this embodiment, the secondary grouting adopts a grouting pipe with
a non-return valve. The mass ratio of slurry used in secondary grouting is: water: cement
=1:1, the volume ratio is: cement slurry: sodium silicate =2:1, and the grouting pressure is
controlled at 0.3 ~ 0.5 MPa, so as to ensure that all the soil sandwiched between holes is
reinforced in place without dead ends.
The advancing speed and attitude control of shield machine directly affect the
settlement of soil. Therefore, the tunneling speed of shield machine should be slowed down when passing through gas station to minimize the disturbance to soil. In the process of crossing, the attitude change of shield machine should not be too large or too frequent, and the deviation of centerline plane position, shield incision and shield tail plane and elevation deviation should be strictly controlled to be no more than 50 mm. Once the shield offset axis is too large or the ground deformation is too large, it should be corrected step by step and the advancing speed should be adjusted in time.
For the attitude control of shield machine, the horizontal range is 0 ~ 20 mm, and the
vertical range is - 20 ~ 0 mm. If it is beyond the range, the operator must adjust it in time,
and then carry out tunneling after getting new tunneling instructions.
In the process of shield tunneling, it is necessary to monitor the section passing
through the gas station, and the monitoring items include: surface settlement, building
settlement, horizontal displacement, inclination and cracks. Settlement monitoring is
carried out on the main facilities of the gas station. In the monitoring process, the existing
monitoring points, oil discharge ports, oil discharge ports and other equipment are mainly
used for direct observation. According to the actual situation of the ground, when the shield
passes through Sinopec gas station, monitoring points should be arranged along the axis of
the tunnel and other necessary positions, and the monitoring points should be monitored at
least 3 times a day, and the measurement results should be fed back in time so that various
construction parameters can be adjusted.
In this method, the sleeve valve tube is used to reinforce the surface by grouting . Due
to the large number of gas station pipelines, no mechanical opening is used as far as
possible, the manual opening tool is chosen to open the hole, the hole depth is 12 m, the
length of embedded ball valve pipe is 12.5 m, and the pipe is made of PPR material.According to the basic form of each building and equipment, under the condition of avoiding the foundation and equipment, the grouting hole shall be fully loaded.
The grouting material of sleeve valve pipe adopts cement slurry: sodium silicate
double slurry; Grouting parameters, including grouting hole layout, grout ratio, grouting
pressure, grouting speed, grouting sequence, grouting time and grouting quantity, are
determined by test results and optimized according to monitoring feedback information
during grouting construction. The recommended values of relevant parameters are as
follows: 0 slurry diffusion radius: R = 1000mm; © Grouting hole spacing: 0.8m, while
it is arranged in plum blossom shape; © Grouting pressure: determined according to the
test during construction; @ Slurry material: No.42.5 ordinary portland cement; Water
cement ratio is 1: 0.75 ~ 1: 1.
The grouting parameters of sleeve valve pipe can refer to the relevant requirements of
ground grouting reinforcement, but the grouting pressure should be controlled in the
grouting process to prevent the foundation of buildings (structures) from being damaged
due to excessive pressure. After grouting, the sleeve valve tube should be washed in time
for reuse.
The steps of sleeve valve pipe grouting are as follows:
Step 1: Prepare grouting slurry according to the selected parameters . After the cement
slurry is matched, filter it with sieve.Connect the grouting pipeline according to the design
and check the grouting system.The grout is mixed before entering the soil.
Step 2: The grouting hole shall be drilled by drilling rig, and the pressure shall be
tested by water injection into the grouting hole, and the injection pressure shall be 1 MPa,
lasting about 2 minutes.
Step 3: After passing the test pressure, use the double-liquid grouting pump, according
to the design pressure, grouting amount timely grouting. When grouting, the pressure is
gradually from low to high, the discharge is gradually reduced and gradually balanced.
Always pay attention to the change of pressure and flow in the pump mouth and hole. If
the pressure does not rise, the flow rate does not decrease, or the pressure increases too fast
after 30 minutes of injection, the flow rate also decreases rapidly, the slurry ratio is changed
or the slurry gel time is adjusted, and the occurrence of pipe plugging accident is prevented.
Step 4: After each hole section reaches the final pressure, and the grouting amount of
the single slurry is less than 20-30 litres/min, stable for 20-30 minutes, the grouting can be
finished. The double liquid slurry pump is less than 30-40 litres/min and can finish grouting
after 20 minutes, according to the field test parameters.
After the left and right lines of shield tunnel pass through the gas station, the
monitoring data show that the accumulative settlement of the surface measuring points in
the gas station area will be the maximum of-10.9 mm (DB45-4) after the shield machine
passes through the gas station, and the settlement of most other surface measuring points
will be within-10.0 mm. The maximum accumulative settlement at the measuring point of
the rain shed is 6.8 mm (northwest corner post measuring point JCG-12), the maximum
accumulative settlement at the base measuring point of the oil depot is 5.5 mm (southwest
corner measuring point JCG-3), and the maximum accumulative settlement of the office
premises of the gas station is 2.9 mm (southwest corner measuring point JCG-7). The
monitoring data rate is small and the alarm value is not reached. Subsequent observations
show that monitoring data have stabilized since 2015.4.1.
Six surface measuring points (DB45-1 ~ DB45-6) and three building (structure) measuring points (maximum accumulated settlement of canopy, oil depot foundation and office building) near the left shield are selected, and the settlement time history curves are given, as shown in Figure 2 and Figure 3 respectively.
Figures 2 and Figure 3 show that the settlement of the surface and the building
(structure) is stable after the left and right lines pass through the gas station. The maximum
accumulative settlement of the surface is-10.9 mm (which is close to the calculated value
of-10.54 mm and the error is 3. 4% ). The reliability of the numerical simulation is verified.
The maximum settlement rate is-1.6mm/d. The maximum cumulative settlement of the
building (structure) is-6.8mm and the maximum settlement rate is-1.1 mm/d, both of which
meet the monitoring requirements. It is shown that the shield tunneling method proposed
in this paper is feasible.
The above-mentioned embodiments only describe the preferred mode of the invention,
not limit the scope of the invention. On the premise of not departing from the design spirit
of the invention, all kinds of deformation and improvement made by ordinary technicians
in the field on the technical scheme of the invention shall fall into the protection scope
determined by the claims of the invention.
Claims (10)
1. The construction control method for a subway shield to penetrate through existing
buildings, which is characterized in that it comprises the following steps:
Si. Acquiring shield construction conditions based on environmental information of
the existing building;
S2. Determining the coring position of the existing building according to the
environmental information in step Sl;
S3. Carrying out hole exploration according to the core position to obtain the soil
sample, and detecting whether the soil sample contain combustible substances or not. If
not, proceed to S4; if yes, return to Sl;
S4. Carrying out shield machine construction according to the detection result of S3
and shield construction conditions, controlling the construction parameters and the posture
of the shield machine, so as to improve the ballast soil, and grouting on the surface for
reinforcement.
2. The construction control method for a subway shield to penetrate through existing
buildings according to claim 1, which is characterized in that the environmental
information of Si existing buildings includes the number, arrangement, buried depth,
volume, height, width, wall thickness and material of the existing buildings.
3. The construction control method for a subway shield to penetrate through existing
buildings according to claim 1 is characterized in that S3 adopts manual hole digging
method for coring.
4. The construction control method for a subway shield to penetrate through existing
buildings according to claim 1 is characterized in that in S4, double track tunneling is adopted for shield tunneling.
5. The construction control method for a subway shield to penetrate through existing
buildings according to claim 4 is characterized in that the double-line tunneling method
comprises the following steps: performing one-line tunneling firstly, and performing the
other-line tunneling after completion of the former.
6. The construction control method for a subway shield to penetrate through existing
buildings according to claim 1 is characterized in that the construction parameters of shield
machine in S4 include tunneling parameters, synchronous grouting parameters and
secondary grouting parameters.
7. The construction control method for a subway shield to penetrate through existing
buildings according to claim 6 is characterized in that the tunneling parameters comprise
thrust, propulsion speed, cutter head rotating speed, earth bin pressure, cutter head torque
and excavated volume.
The grouting amount of the synchronous grouting is 1.3-1.8 times the annular gap
volume, 3.5-4.5 m3/ring grouting amount and 0.2-0.3 MPa;
The secondary grouting pressure is 0.01-0.03 MPa higher than the synchronous
grouting pressure, and the secondary grouting adopts a grouting pipe with a check valve.
8. The construction control method for a subway shield to penetrate through existing
buildings according to claim 1 is characterized in that in S4, the surface grouting
reinforcement adopts a sleeve valve tube reinforcement method.
9. The construction control method for a subway shield to penetrate through existing
buildings according to claim 1 is characterized in that in S4, the method of improving
ballast soil is to adjust the amount of foaming agent and bentonite in the process of shield machine excavation based on the speed of excavation, the torque of the cutter head and the condition of ballast discharging.
10. The construction control method for a subway shield to penetrate through existing
buildings according to claim 8 is characterized in the following content:
The sleeve valve tube reinforcement method comprises the following steps:
Drilling the grouting hole and injecting water into the grouting hole to test the internal
pressure of the grouting hole;
The grouting slurry shall be pumped into the grouting hole after the internal pressure
test of the grouting hole passes;
When grouting, the pressure is gradually reduced from low to high, and the
displacement is gradually reduced and balanced, which is normal . Otherwise, the slurry
ratio is changed or the gel time is adjusted.
After each grouting hole reaches the final pressure, and the grouting amount of single
liquid slurry is less than 20-30 litres/min, after stable for 20-30 minutes, the grouting is
finished.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2021101943A AU2021101943A4 (en) | 2021-04-15 | 2021-04-15 | A construction control method for a subway shield to penetrate through existing buildings |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| AU2021101943A AU2021101943A4 (en) | 2021-04-15 | 2021-04-15 | A construction control method for a subway shield to penetrate through existing buildings |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| AU2021101943A4 true AU2021101943A4 (en) | 2021-06-03 |
Family
ID=76132915
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| AU2021101943A Ceased AU2021101943A4 (en) | 2021-04-15 | 2021-04-15 | A construction control method for a subway shield to penetrate through existing buildings |
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| Country | Link |
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| AU (1) | AU2021101943A4 (en) |
Cited By (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114508357A (en) * | 2021-11-30 | 2022-05-17 | 中交隧道工程局有限公司 | Synchronous double-liquid grouting process for large-diameter shield tunnel |
| CN114578713A (en) * | 2022-03-17 | 2022-06-03 | 山东拓新电气有限公司 | Attitude control method and device for push bench |
-
2021
- 2021-04-15 AU AU2021101943A patent/AU2021101943A4/en not_active Ceased
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN114508357A (en) * | 2021-11-30 | 2022-05-17 | 中交隧道工程局有限公司 | Synchronous double-liquid grouting process for large-diameter shield tunnel |
| CN114578713A (en) * | 2022-03-17 | 2022-06-03 | 山东拓新电气有限公司 | Attitude control method and device for push bench |
| CN114578713B (en) * | 2022-03-17 | 2022-09-13 | 山东拓新电气有限公司 | Attitude control method and device for push bench |
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