CN111101958A - Construction method for tunnel shield interval lower penetrating and winding city - Google Patents
Construction method for tunnel shield interval lower penetrating and winding city Download PDFInfo
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- CN111101958A CN111101958A CN202010027193.5A CN202010027193A CN111101958A CN 111101958 A CN111101958 A CN 111101958A CN 202010027193 A CN202010027193 A CN 202010027193A CN 111101958 A CN111101958 A CN 111101958A
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Classifications
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- 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
- E21D9/08—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining with additional boring or cutting means other than the conventional cutting edge of the shield
- E21D9/087—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining with additional boring or cutting means other than the conventional cutting edge of the shield with a rotary drilling-head cutting simultaneously the whole cross-section, i.e. full-face machines
- E21D9/0873—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining with additional boring or cutting means other than the conventional cutting edge of the shield with a rotary drilling-head cutting simultaneously the whole cross-section, i.e. full-face machines the shield being provided with devices for lining the tunnel, e.g. shuttering
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- 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
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- 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
- E21D11/04—Lining with building materials
- E21D11/08—Lining with building materials with preformed concrete slabs
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- 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
- E21D11/04—Lining with building materials
- E21D11/10—Lining with building materials with concrete cast in situ; Shuttering also lost shutterings, e.g. made of blocks, of metal plates or other equipment adapted therefor
- E21D11/105—Transport or application of concrete specially adapted for the lining of tunnels or galleries ; Backfilling the space between main building element and the surrounding rock, e.g. with concrete
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- 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
- E21D9/003—Arrangement of measuring or indicating devices for use during driving of tunnels, e.g. for guiding machines
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- 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
- E21D9/0642—Making by using a driving shield, i.e. advanced by pushing means bearing against the already placed lining the shield having means for additional processing at the front end
- E21D9/0678—Adding additives, e.g. chemical compositions, to the slurry or the cuttings
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- G—PHYSICS
- G01—MEASURING; TESTING
- G01D—MEASURING NOT SPECIALLY ADAPTED FOR A SPECIFIC VARIABLE; ARRANGEMENTS FOR MEASURING TWO OR MORE VARIABLES NOT COVERED IN A SINGLE OTHER SUBCLASS; TARIFF METERING APPARATUS; MEASURING OR TESTING NOT OTHERWISE PROVIDED FOR
- G01D21/00—Measuring or testing not otherwise provided for
- G01D21/02—Measuring two or more variables by means not covered by a single other subclass
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- Engineering & Computer Science (AREA)
- Mining & Mineral Resources (AREA)
- Geology (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
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- Architecture (AREA)
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- Excavating Of Shafts Or Tunnels (AREA)
Abstract
The invention discloses a construction method for penetrating and winding a city under a tunnel shield interval, which comprises the following steps: step 1: tunneling a test section; step 2: formally tunneling; and step 3: mounting a duct piece; and 4, step 4: grouting; and 5: monitoring and adjusting; and each step is improved, so that the aim of safely and accurately winding the city at 45 degrees is fulfilled in the construction of penetrating and winding the city under the shield region.
Description
Technical Field
The invention relates to the field of tunnel construction, in particular to a construction method for a tunnel shield zone lower crossing and winding city.
Background
Under the surface of an urban highway, in the construction of an underground tunnel penetrating through an urban highway, an innovative construction method for a special construction section is needed, and the tunneling construction of the existing tunnel urban-surrounding construction method is improved so as to safely monitor the construction and realize the designed urban-surrounding angle.
Disclosure of Invention
The invention aims to solve the technical problem of providing a construction method for a tunnel under a shield region of a tunnel to penetrate around a city, and provides a new construction method.
The technical problem to be solved by the invention is realized by the following technical scheme:
a construction method for a tunnel shield zone lower penetrating and winding city comprises the following steps:
step 1: tunneling a test section;
step 2: formally tunneling;
and step 3: mounting a duct piece;
and 4, step 4: grouting;
and 5: monitoring and adjusting;
the step 1 comprises the following steps:
determining shield propulsion parameters: setting the pressure of a soil bin of the shield machine to be more than 0.6-0.8bar, the tunneling propulsion speed to be 25-35mm/min, the rotating speed of a cutter head to be less than 1.1 r/min, controlling the stratum loss rate to be within 2 percent, and controlling the shield propulsion pressure to be not less than 0.8 time of the water and soil pressure; grouting synchronously during tunneling;
determining grouting pressure and grouting amount: the grouting amount of each ring is 120-150% of the building gap; the synchronous grouting amount is not less than 5.0m per pushing ring3；
Determining the pressure of secondary slurry supplement, wherein the secondary slurry supplement adopts double-fluid slurry or a shield machine with a plunger pump; and (4) injecting the slurry once in each ring when the shield passes through the risk zone, wherein the pressure of the slurry injected each time is 0.3-0.5 Mpa.
The step 2 of formal tunneling comprises the following steps:
determining the range of crossing the city-surrounding highway: the distance between a cutter head of the shield machine and the roadbed is 15m, and the distance between a shield tail and the roadbed is 15 m;
and determining the tunneling soil pressure as follows: the soil pressure fluctuation is within 0.1bar, and the foam soft soil pressure is used in cooperation;
determining the tunneling soil output: the soil output is uniformly controlled according to the footage and the soil pressure in the shield tunneling process, the soil output is matched with the grouting amount, and the soil output is as follows: the muck truck is filled to about 18m3Pushing the soil output of 1.5 m;
determining a hinging device reasonably using the shield, and controlling the shield tunneling axis: calculating the turning angle of each step of shield middle folding according to the deviation degree of the shield, firstly opening a profiling cutter of the shield to carry out over-excavation construction, wherein the over-excavation length is from half to one shield body of the shield, then adjusting a shield middle folding device according to the calculation, then assisting in jack marshalling and partition oil pressure control to carry out tunneling construction, and adjusting the turning angle at any time according to shield posture data during advancing until the shield machine returns to the design axis;
the step 3 segment installation comprises: controlling the installation quality of the duct piece: firstly, measuring the shield tail, and then selecting the K block position according to the stroke of the oil cylinder, the parameters provided by the measuring system and the track and trend.
The step 4 grouting comprises synchronous grouting and second and third grout supplementing: adjusting the proportion and the grouting mode of grouting to control the initial setting time within 8 hours, wherein the grouting material is pure cement slurry with the weight ratio of water to cement being 1: 1; performing secondary slurry filling after the wall on the pipe piece outside the 5 rings at the rear part of the shield tail; the third-time slurry supplementing is to reserve a grouting hole at the top of each ring of pipe piece and install a grouting plug for grouting from the middle part or the tail part of the shield tunneling machine, and the grouting slurry adopts cement and water glass double-liquid mixed slurry;
after the shield machine is shut down, injecting a proper amount of foam and thick bentonite slurry into the cutter head and the soil bin, wherein the bentonite slurry is proportioned with water in parts by weight: the soil is 700: 300;
and (3) the bentonite slurry is injected into the soil bin with the average soil pressure of more than 1.5bar so as to maintain the water and soil pressure balance of the whole excavation surface.
In the shield crossing process, a left shield carries out wall back grouting holes on corresponding duct pieces, after grouting floral tubes are inserted into walls, deep hole grouting is carried out on the periphery of the interval structure through the wall back grouting holes, grouting amount and grouting pressure are synchronized, unconfined uniaxial compressive strength is greater than 1MPa, and large-range deep hole grouting adjustment of grouting pressure ensures that effective diffusion radius is greater than 0.5 m;
the step 5 of monitoring and adjusting further comprises: the method for observing the duct piece settlement comprises the following steps: the settlement and convergence monitoring points of the segment structure are 1 point distributed for the number not exceeding every 5 rings, and measuring points are arranged on segments of the side line of the tunnel ballast bed:
the duct piece settlement monitoring method comprises the following steps: and leveling base points for vault settlement are distributed in or outside the hole, a reinforcing steel bar with the diameter of 6mm is bent into a triangle, the triangle is fixed at the vault part on the side to be measured, leveling measurement is carried out by an electronic leveling instrument footfall method, and the elevation of a settlement point is measured.
The step 5 of monitoring and adjusting further comprises: shield tunnel clearance convergence monitoring: the empty convergent measuring points and the structural vault settlement cloth are distributed on the same section; the method comprises the following steps of arranging clearance convergence of a single-wire tunnel and clearance convergence of a communication channel; a point distribution principle: the net hole depth is 20mm, the convergent embedded parts are inserted after the bar planting glue is filled in the hole, the axes of the two embedded parts are in the base line direction, and monitoring can be carried out when the bar planting glue in the hole is solidified; and (5) measuring by using a convergence meter and combining temperature monitoring.
The step 5 of monitoring and adjusting further comprises: monitoring the surface settlement, wherein the monitoring point arrangement principle is as follows: burying a ground surface settlement monitoring point requiring penetration of a pavement structure layer; the measuring point is provided with a protective cover, the aperture is larger than or equal to 80mm, and the embedding method comprises the following steps: excavating holes with the diameter of about 130mm and the depth of about 1m on the soil surface, and tamping the bottoms of the holes; removing residue soil, and injecting a proper amount of clear water into the hole for curing; placing a steel bar mark with the length not less than 100cm in the center of the hole, exposing the filler surface by about 1-2 cm, and backfilling and tamping coarse sand, wherein the height of a measuring point is lower than the height of a road surface; a steel protective cover with the diameter not less than 110mm is additionally arranged at the upper part; maintaining for more than 15 days.
The step 5 of monitoring and adjusting further comprises: performing shield tunneling measurement, establishing a shield control point, and establishing the control point at an immovable position of a shield; after the shield is installed on site, measuring the coordinates of the shield control point in the engineering coordinate system; measuring the rotation angle and the gradient of the shield by an inclinometer in the ELS; inputting the basic size and the measurement data of the shield into a DDJ-2S system, arranging a laser total station on a measuring table, and starting the DDJ-2S system, so that the system can automatically acquire data every 30 seconds.
Measuring the position of the duct piece: after the propelling is finished, inputting a gap value between the pipe piece and the shield tail, obtaining an extension value of the jack and a shield hinging state through the PLC, and calculating the offset of the pipe piece and a design axis; calculating the three-dimensional coordinate of the circle center and the corresponding tunnel design coordinate according to the measured three-dimensional coordinate of the formed segment, and finally calculating a deviation value;
and (3) measuring the shield attitude: measuring a characteristic point and a characteristic axis when the real-time attitude of the shield tunneling machine is measured, selecting the center of a notch of the shield tunneling machine as the characteristic point, and selecting a longitudinal axis of the shield tunneling machine as the characteristic axis; the azimuth angle of the longitudinal axis of the guide line is controlled by using tunnel construction, and the difference between the azimuth angle and the azimuth angle of the shield is an azimuth angle correction value, so that the shield tunneling direction is corrected;
and (3) measuring lining ring pieces: measuring the ring center deviation of the lining ring, the ovality of the ring and the posture of the ring; measuring the lining ring piece for at least 3-5 rings, wherein each ring is 1.5m, measuring each ring during measurement, and measuring the front end face of the ring to be measured; and 5, overlapping and measuring ring sheets when measuring adjacent lining rings.
Compared with the prior art, the invention has the following advantages:
the invention comprises the following steps of 1: tunneling a test section; step 2: formally tunneling; and step 3: mounting a duct piece; and 4, step 4: grouting; and 5: monitoring and adjusting; and each step is improved, so that the aim of safely and accurately winding the city at 45 degrees is fulfilled in the construction of penetrating and winding the city under the shield region.
Drawings
FIG. 1 is a plan view of a 100 m test section for city-surrounding high-speed tunnel construction according to the invention
FIG. 2 is a plan view of the shield tunnel of the present invention with additional grouting holes
FIG. 3 is a high-speed cross-sectional view of the shield tunneling through the city
FIG. 4-1 is a view showing the observation of the duct piece settlement of the present invention
FIG. 4-2 is a diagram of single-line tunnel headroom convergence monitoring of the present invention
FIGS. 4-3 illustrate convergence of headroom for communication channels in accordance with the present invention
FIGS. 4-4 are the burying diagrams of the ground subsidence monitoring points of the present invention
1-segment, 2-grouting hole embedded part, 3-grouting hole, 4-level bar, 5-turning point and 6-monitoring point.
Detailed Description
As shown in fig. 1, fig. 2, fig. 3, fig. 4-1, fig. 4-2, fig. 4-3 and fig. 4-4, a method for constructing and monitoring a tunnel under a shield zone of a tunnel includes the following steps: tunneling a test section, formal tunneling, grouting, duct piece installation, monitoring and adjusting.
The city-surrounding shield area interval is respectively a three-color road, a neutralization station, a gold stone road station-three-color road station shield interval, a three-color road station-neutralization station shield interval, and a Longdeng mountain entrance and exit section line shield interval. According to the preliminary design drawing, the total length of a left line is 1027m and the total length of a right line is 1090m in a golden three-interval; the total length of the left line and the right line of the third-middle interval is 2589.9m and 2593.6 m; the left line and the right line of the outgoing line section of the dragon lantern mountain vehicle are respectively 2414m long, and the incoming line section is 447m long; the ends of the big mileage and the small mileage of the three-color road station are both shield starting, and the Longdenshan vehicle section is shield starting with the small mileage.
Engineering geology a high-speed geological profile around a city as shown in fig. 3: covering a fourth system of completely new artificial filling soil layer within the field range according to the drilling revelation; the fourth system is totally new flood-filling laminated silty clay, viscous silty soil, fine sand, medium sand and pebble; the underburden is a chalk system top system flow set mudstone.
And (3) construction planning: the shield starting well between the three-color road station and the neutralization station is arranged at the large mileage end of the three-color road station, and the shield starts to send out the three-color road station and then tunnels to the south, and receives the three-color road station and the small mileage end of the neutralization station.
Before the city-surrounding expressway is wound, the main work in the technical aspect is to optimize tunneling parameters, analyze geological conditions, hydrological conditions, tunnel covering soil thickness, ground conditions and the like within an influence range, establish reasonable tunneling parameters and control settlement. The method comprises the following steps:
1. and optimizing the circuit scheme. According to the subway No. 6 line planning network scheme and the preliminary design station position scheme, the intersection angle of the line plane between the area from gold to three to middle and the plane around the city at high speed is optimized, and the track surface burial depth of the area of the ground is increased by the longitudinal section of the speed regulating line. And adjusting the intersection angle of the optimized subway line and the high-speed plane to be about 45 degrees at most among the Jinxianzi and the Sanzhong areas according to the current line station position condition, covering soil for the tunnel in the area of 23.7m, and keeping the distance from the top of the tunnel to the bottom of the roadbed to be about 17.4 m.
2. And (5) reinforcing the roadbed of the urban highway. As shown in figure 2, a reserved grouting hole layout diagram is additionally arranged in the shield tunnel, a grouting pipe 2 of a grouting hole 3 is reserved in a tunnel segment 1, and a grouting hole embedded part is reserved. The roadbed section of the highway passing through and around the city does not have ground reinforcing conditions, and the reinforcing measures in the tunnel are mainly adopted when the shield passes through the section. Grouting reinforcement in the tunnel increases the grouting holes 1 of the adjacent blocks of the shield segments and the standard blocks into 3 by 1, after the shield passes through, grouting pipes are arranged by utilizing the grouting holes or hoisting holes, and the grouting reinforcement is immediately performed on the ground layer in a certain range of the vault and the arch shoulders of the shield tunnel. The grouting material is determined by field tests according to the position of cement grout and grouting parameters including grout proportion, grouting pressure, grouting sequence, grouting time, grouting amount and the like, and is optimized according to monitoring feedback information in grouting construction.
The construction method of the test section is as shown in a test section plan view in figure 1:
because the down-through city expressway is an irreversible process, and the requirement on settlement control when the shield is down-through is far higher than that when the shield passes through a common area, the surrounding environment and geological conditions need to be investigated in detail before the shield passes through the city expressway, and the model selection, the cutter head form and the opening rate, the cutter configuration, the cutter head driving, the total assembly thrust, the shield tail sealing, the shield tail grouting and the like of the shield machine are considered according to the geological and hydrological conditions. The length of the front 100 meters of the expressway near the city is taken as a test section, the correlation of the surface subsidence of the tunneling parameters of the shield tunneling machine in different stratums is mastered according to ground deformation monitoring data and parameters adopted by shield construction, the stability of a tunnel face is ensured, the disturbance to the stratum and the stratum loss in the excavation process are reduced as much as possible, and the stratum loss rate caused by soil discharge is strictly controlled within 2%. The test section is close to the shield tunnel burial depth, hydrology and geological conditions of the risk protection area to be penetrated, the test section takes the settlement control standard of the protection area as a target, and shield parameters are continuously adjusted, so that the shield parameters capable of controlling the settlement of the protection area are obtained.
1. Shield propulsion parameter determination
According to the stratum characteristics and past experience of the Chengdu area, the pressure of the earth bin of the shield machine is controlled to be not less than 0.6-0.8bar, and during tunneling, adjustment is carried out according to the parameters of the shield machine, the slag discharge condition, the ground settlement condition, the stratum burial depth and other conditions. The propelling speed is temporarily set to be 25-35mm/min, the rotating speed of the cutter head is controlled within 1.1 r, the speed is as stable as possible, the high and low conditions are forbidden, the synchronous grouting speed is well controlled, and the smooth grouting of the slurry is ensured.
2. Determination of grouting pressure and grouting quantity
① synchronous grouting pressure and grouting quantity determination
Because the grout pressed into the back of the lining can be subjected to water loss shrinkage consolidation, part of the grout can be split into surrounding strata, and the actual grouting amount needs to exceed the theoretical building void volume due to curve propulsion, deviation correction or shield tunneling machine head raising and the like. According to construction experience, the grouting amount of each ring is 120-150% of the building gap generally.
The theoretical building clearance per ring of propulsion is:
π×3.14×3.14×1.5-π×3.0×3.0×1.5＝4.05m3
the outer diameter of the cutter head: phi 6280 mm;
segment outer diameter: phi 6000mm
The grouting amount of each ring is generally 120-150% of the building gap, and the synchronous grouting amount of each ring is 5.0m3Not less than that.
② pressure determination for secondary slurry make-up
The secondary grouting adopts double-fluid grout, and grouting is performed for each ring when the risk zone is crossed, and the grouting pressure and the grouting amount are determined as follows: the shield tunneling parameters are strictly controlled, and the stratum loss rate is controlled within 2 percent, and the shield propelling pressure is not less than 0.8 time of the theoretical water and soil pressure. And (3) timely and synchronously grouting after the shield passes through, and controlling the synchronous grouting amount and the grouting pressure by paying attention to the unconfined uniaxial compressive strength not less than 1 MPa. The secondary reinforcing grouting adopts a self-contained double-liquid grouting pump or a shield machine with a plunger pump. The secondary grouting pressure is 0.3-0.5 Mpa.
The main points of this test section through test section summary: determining tunneling parameters of crossing the risk zone, including cutter head rotating speed, thrust, torque and propulsion speed; analyzing the monitoring data and mastering the relationship between the propulsion parameters and the settlement; determining the grouting amount, grouting pressure and grouting speed of each ring through monitoring data; and summarizing the optimal time for secondary pulp replenishing.
3. The high-speed construction method of the shield lower penetrating and winding city comprises the following steps:
(1) the range of traversing the city-around highway is determined. According to the actual conditions of the soil covering depth and stratum of the expressway dyed by the shield penetrating through, the radius of the influence range of the shield excavation on the surrounding soil body is about 15m, namely the construction range of the shield tunneling machine which is 15m away from a cutter head of the shield tunneling machine to a roadbed and 15m after a shield tail passes through the roadbed is a construction range of penetrating through the high speed around the city
(2) One of the key points of the high-speed successful crossing around the city is construction parameters and experience, soil pressure control, grouting eye control and management, grouting amount control, additive use management, propelling speed matching, cutter head torque and rotating speed control and the like.
(3) The production management system is strictly implemented between the crossing and city-surrounding high speed, elaborate preparation and elaborate construction are carried out, detailed technology and safe intersection are achieved, the construction site is served around the crossing and city-surrounding high speed construction, and the safety, smoothness, quality and quantity guarantee in the crossing construction process are ensured. The construction is carried out in a high-speed forming area strictly according to the technical background content, and the technical background content comprises the following steps: thrust range, soil pressure control range, soil discharge amount of each ring, grouting amount of each ring, foam adding proportion, cutter head speed and torque control range.
(4) The tunneling soil pressure is strictly controlled in the construction process. The soil pressure stability of a tunneling surface is strictly kept in the shield tunneling process, the soil pressure fluctuation is within the range of 0.1bar, the soft soil pressure such as foam is reasonably used, the running water of underground water is prevented, the settlement caused by shield tunneling and excavation is ensured to be within the allowable range, people are sent to pay close attention to the soil pressure change when the machine is stopped, and measures are taken in time when the preset value is exceeded. The earth pressure is kept uniform and prevented from being suddenly high or low. The shield machine driver is required to carefully operate the traditional Chinese medicine in the operation process, and the propelling speed, the spiral rotating speed and the cutter head rotating speed are in smooth transition. The soil pressure control needs to be closely matched with the ground monitoring, and if the ground monitoring finds that the ground in front of the cutter head always rises and exceeds an early warning value, the soil pressure needs to be properly reduced at the moment; the earth pressure should be increased instead. The earth pressure ground monitoring forms a good feedback channel, so that a shield driver can adjust earth pressure control parameters in time.
(5) The soil output is strictly controlled. And in the shield tunneling process, the soil output is strictly and uniformly controlled according to the footage and the soil pressure, and the soil output is matched with the grouting amount.
According to a formula for calculating the soil output of each ring: vDeficiency of Qi＝K×π×D2×L/4
Wherein: k is soil bulk coefficient, which depends on soil quality, shield tunneling parameters, soil improvement condition and the like, the engineering soil quality of the section is silty clay and silty soil, and the comprehensive bulk coefficient K is 1.2;
d is the diameter of the shield machine, 6.28 m;
l-tunneling length, 1.5m
V virtual-K × pi × D2×L/4＝1.2×π×6.282×1.5/4＝55.7m3
During the tunneling, the loading capacity of the ballast car is observed and recorded, and the soil excess is strictly forbidden. Once a problem is found, measures are taken immediately. Soil output: the muck truck is filled to about 18m3The soil output of 1.5m is controlled to be about 4 vehicles.
(6) And strictly controlling the shield tunneling axis. The control of the shield axis is the key point of the shield method, and is an important lead wire for ensuring the smooth construction of the shield, and the following points must be paid attention to during curve tunneling:
1) and controlling the technical parameters of tunneling, such as soil pressure, pushing speed and the like. When the soil pressure is too low, not only the settlement of the stratum is easily caused, but also the control of the shield axis is influenced, and the shield sinking is easily caused; in addition, the position and pressure of the grouting pressure are larger in disturbance to the stratum on the one hand, and on the other hand, the shield can move towards the grouting position, so that the axial control of the shield is not facilitated;
2) correctly carrying out the marshalling of the shield jack and the control of the zonal oil pressure, and selecting the jack correctly or not during propulsion to relate to the track of the shield axis;
3) the hinge joint device of rational use shield constructs, when the shield structure skew tunnel design axis is more, the shield constructs when carrying out little radius curve construction or when the shield structure gesture is extremely poor, through the marshalling of adjustment jack and selection and subregion oil pressure control have more difficult to reach the purpose when, hinge joint device is opened to the accessible, specific operation is: calculating the turning angle of each step of shield middle folding according to the deviation degree of the shield, firstly opening a profiling cutter of the shield to carry out over-excavation construction, wherein the over-excavation length is generally half to one shield body length of the shield, then adjusting a shield middle folding device according to the calculation, then assisting with jack marshalling and partition oil pressure control to carry out tunneling construction, and adjusting the folding angle at any time according to the shield posture data during advancing until the shield machine returns to the design axis.
4) Strict control of segment assembling quality. Firstly, measuring the shield tail, and then selecting the K block position according to the stroke of the oil cylinder, the parameters provided by the measuring system and the track and trend. Before the duct piece assembling manipulator is assembled, whether the duct piece and the water stop adhesive tape are damaged or not needs to be checked, if damaged, the duct piece cannot be repaired, and sundries such as silt and the like on the water stop adhesive tape are cleaned. And (4) cleaning silt and sewage deposited in the shield tail.
The assembling machine is operated to be as soft as possible during assembling, so that the water-stopping rubber strips and the pipe pieces are prevented from being damaged due to severe impact between the pipe pieces. The longitudinal and circumferential pipe pieces are flat and smooth in plane and are not staggered. After each segment is assembled, the bolts are screwed in time, and the bolts of the whole ring segments are retightened after the whole ring is assembled. And (4) re-tightening the bolt of the duct piece after the duct piece is separated from the shield tail.
5) Synchronous grouting and secondary and tertiary grout supplement. When the crossing city-winding high-speed construction is carried out, the grouting proportion and the grouting mode are adjusted, the initial setting time is controlled within 8 hours, a grout test is carried out on site in advance, and optimization is carried out according to a test structure. In order to ensure that slurry is densely filled outside the pipe piece and ground settlement is reduced, wall post-wall secondary slurry filling is carried out on the pipe piece outside the 5 rings at the rear part of the shield tail, pure cement slurry with the water-cement ratio of 1:1 is selected as a grouting material, and grouting pressure is determined according to a test and trial structure.
The grouting operation is a key process in shield construction. In order to prevent soil from extruding into the gap of the shield tail, the grouting amount must be ensured to be 130-150% of a theoretical calculated value according to a double guarantee principle of ensuring grouting pressure and considering grouting amount, and the following control measures are taken:
1) and (3) grouting operation, wherein the grouting amount needs to be recorded after each ring of tunneling is finished, when the grouting amount is found to be large, the reason is analyzed carefully, grouting is supplemented by methods such as increasing grouting pressure, and secondary or tertiary grouting needs to be performed in time when the supplementary grouting cannot be performed.
2) Four-point grouting is adopted in shield construction in the area to control the quality of the formed tunnel.
3) After the assembly of the non-replaced pipe pieces is finished, grout is supplemented, and after the shield tail pressure reaches the set pressure and is kept relatively stable, the next ring of construction can be carried out. In addition, in order to shorten the setting time of the slurry, the slurry is changed into cement mortar, and the fly ash in the original ratio is changed into cement. The proportioning of the slurry is adjusted in time according to the grasped feedback information, so that the proportioning of the slurry is more scientific and reasonable. In order to ensure the quality of the slurry, the raw materials for preparing the slurry are strictly controlled, and the slump, viscosity, segregation rate, setting time, compressive strength and the like of the slurry are periodically measured.
And the third-time slurry supplementing is arranged at the middle part or the tail part of the trailer, and a grouting hole reserved at the top of each ring of pipe piece is provided with a grouting plug for grouting according to the settlement monitoring condition, and the grouting slurry adopts cement-water glass double-liquid slurry.
(4) And (5) shield operation control. Before the high-speed area is bypassed, the axis of the shield is controlled as good as possible, no deviation correction or few deviation correction is strived for in the crossing process, and the over excavation is achieved as few as possible. And strictly controlling the stroke difference of the four propelling oil cylinders and the stroke difference of the hinged oil cylinders, and controlling the gap of the shield tail.
1) In order to keep the stability of the excavation face, prevent the soil body from collapsing around, the cutter head of the shield machine is locked, the starting torque of the cutter head is too large, after the shield machine is stopped, proper foam and thick bentonite slurry are injected into the cutter head and the soil bin, and the bentonite slurry is proportioned according to the weight part ratio: water: the soil is 700:300, and bentonite slurry needs to be prepared in advance and fully fermented. During the shutdown, the average soil pressure in the soil bin is established to be more than 1.5 bar; in the process of injecting bentonite slurry, the cutter head is rotated simultaneously, so that sandy soil in the bin is fully mixed with the slurry, a slurry skin is formed on the periphery of the excavation surface and the cutter head, and the requirement of keeping the excavation surface stable is met.
2) When the machine is stopped for more than 24 hours, in order to prevent the dissipation of foam, the stability of the excavation surface is maintained only by injecting thick bentonite slurry, the change of the soil pressure in the bin is closely noticed during the machine is stopped, and when the average soil pressure is 1bar, particularly when the upper soil pressure is lower than 0.6bar, the bentonite slurry is timely injected to maintain the water-soil pressure balance of the whole excavation surface.
The technical measures are as follows:
the shield tunnel passes through the section and winds the city at a high speed in the range from the three-color road to the neutralization station. The thickness of the shield tunnel covering soil is about 27.5m, and the minimum distance between the shield tunnel and the bottom of the roadbed is about 20.6 m.
The following measures are taken in the downward penetration period of the shield construction: for example, a reserved grouting hole layout diagram is additionally arranged in the shield tunnel in fig. 2.
①, pre-judging the accident situation before construction, and making a perfect emergency plan, construction scheme and emergency plan for title unit record;
② before crossing, the shield machine should be adjusted to ensure good performance, the tunneling parameters are strictly controlled to ensure uniform speed passing, and the tunneling soil pressure and the soil output are strictly controlled in the construction process.
③ the shield tail should be timely grouted to fill the gap between the segment and the soil body and strictly control the grouting amount and grouting pressure.
④ in the process of shield crossing, the settlement monitoring of the road surface is enhanced, and the shield tunneling parameters are adjusted in time according to the monitoring result, so that the safety is ensured.
⑤ in the crossing process of the shield, the left shield carries out wall back grouting holes on corresponding pipe pieces in the construction range, after grouting pipes are inserted into the wall, deep hole grouting is carried out on the periphery of the interval structure through the wall back grouting holes, the grouting amount and the grouting pressure are synchronized, the unconfined uniaxial compressive strength is not less than 1MPa, before the large-range deep hole grouting, a grouting test is carried out in advance, reasonable indexes such as slurry proportion and grouting pressure are determined, relevant parameters such as the grouting pressure can be properly adjusted if necessary, the effective diffusion radius is ensured to be larger than 0.5m, and the relevant requirements of grouting reinforcement bodies are met.
The construction monitoring is as shown in the monitoring structure schematic diagrams of fig. 4-1, fig. 4-2, fig. 4-3 and fig. 4-4.
The monitoring aims to monitor the settlement and the inclination of the cracks of the roadbed, the pier body and the beam body in the influence range, the stress of main components, the crack variation quantity and other items in the high-speed process of the underground crossing and winding city, and master the state change of the high-speed surrounding city before and after the subway construction. The ground settlement is controlled, and the high-speed safety and stability of the shield tunneling machine passing through the surrounding city are ensured.
(1) When the city is passed through and wound at a high speed, monitoring is carried out for 24 hours, and monitoring is carried out once every 6-8 hours. And the measurement result is fed back to the main control room in time.
(2) When the shield machine is at a high speed around the city, the ground (including pipeline) condition is observed for 24 hours, the ground and the displacement of the bridge pile of the high-speed overhead bridge around the city are measured, and the influence degree of the shield machine at the high speed around the city is analyzed and judged.
(3) An effective ground and shield control room communication contact mode is adopted, and the contact contents comprise shield tunneling mileage, tunnel operation conditions and the like.
Monitoring measurement items and standards:
before construction, the defects and damages of the high-speed bridge and the roadbed section around the city are comprehensively and carefully investigated on site, and the technical conditions of the related structures are comprehensively known. The method mainly comprises investigation contents such as cracks of pier bodies and beam bodies, support states, equipment on bridges, roadbed flatness and the like.
Data processing:
the method comprises the steps of adopting a geometric leveling method for monitoring building settlement, underground pipeline settlement and differential settlement and road surface settlement, adopting a Tianbao Dini03 electronic level for observation, and adopting an electronic recording field observation data, wherein the method is shown in figure 4-1. The level bar 4 passes through section of jurisdiction bottom commentaries on classics point 5, and section of jurisdiction top monitoring point 6 sets up on level bar 4, and this level bar 4 cooperates with the electronic level support. As shown in fig. 4-1.
After the elevation datum point is selected, at least 3 times of repeated measurement is needed, and the elevation datum point can be used when the elevation datum point is confirmed to be in a stable state.
Data adjustment calculation
And forming an original observation record file after the observation is finished, and performing strict adjustment by using special leveling net adjustment software after the observation is qualified to obtain the elevation value of each point.
The adjustment calculation requirements are as follows:
1) the stable reference points are used as starting points, and the independent closure difference and the mutual coincidence difference with more than 2 reference points are checked;
2) calculating by using professional adjustment software according to a strict adjustment method;
3) after adjustment, the data bit should be accurate to 0.1 mm.
And calculating data such as settlement of each stage, stage deformation rate, accumulated settlement and the like through elevation values of each stage of the deformation observation point.
The principle of analysis of the stability of the monitoring points is as follows:
1) the stability analysis of the monitoring points is carried out based on stable reference points;
2) the change of the monitoring points in two adjacent periods is carried out by comparing the maximum deformation and the maximum measurement error (twice the error), and when the deformation is less than the maximum error, the monitoring points are considered to have no change or have insignificant change in the period;
3) for the observation result of multi-phase deformation, when the deformation amount of adjacent cycles is small, but the multi-phase deformation shows obvious change trend, the observation result is regarded as having variation.
The prediction of the deformation rule of the monitoring points can be given by mathematical calculation modes such as regression analysis and the like, and comparison is carried out by combining simulation calculation such as geological conditions, structural design forms, construction steps and the like.
And the monitoring point early warning judgment is given out by comparing the double-control index with the early warning, alarming and controlling indexes according to the deformation rate and the accumulated deformation.
The method for monitoring the settlement of the duct piece comprises the following steps: as shown in fig. 4-1.
1. The main purposes are as follows: (1) dynamically mastering the deformation of a shield tunnel structure, and verifying whether tunnel settlement and horizontal displacement caused by construction are controlled within an allowable range so as to take necessary control measures; (2) and an early warning mechanism is formed, and the occurrence of structural safety risk accidents is avoided.
2. Requirement for measuring point arrangement
The settlement and convergence monitoring points of the segment structure are 1 point distributed in every 5 rings, the monitoring points can be properly encrypted at certain specific positions, the point positions are convenient to monitor and can be stored for a long time, measuring points are generally arranged on the segments on the side line of the tunnel track bed, and the distribution principle is as follows:
(1) each 10 rings are provided with monitoring sections;
(2) monitoring sections are arranged at the shield launching and receiving section, the vicinity of the communication channel, the overlapping or adjacent of the left line and the right line, the small-radius curve section, the section with abnormal construction and the segment structure cracking;
(3) presence of formation bias, surrounding rock
Laying monitoring sections in complicated geological sections with uneven hardness and other geological conditions;
(4) and monitoring sections are laid in the areas with complicated surrounding environmental conditions.
Monitoring method
(1) The leveling base points for vault settlement are arranged in or outside the hole and are firmly fixed or suitable for measurement.
(2) Vault settlement generally adopts phi 6mm reinforcing bar to bend into a triangle, fixes the vault position on waiting the side.
(3) Leveling measurement is carried out by adopting an electronic leveling instrument to pour a ruler, and the elevation of a settlement point is measured.
The headroom converges as shown in fig. 4-2, fig. 4-3.
1. Purpose of monitoring
After the shield tunnel starts, the clearance convergence in the tunnel is the most direct and obvious parameter for reflecting the mechanical form change of the surrounding rock and the supporting structure. The stable state of the surrounding rock and the supporting structure can be known through monitoring.
2. Principle of point distribution
The measuring points of clearance convergence and the structure vault settlement are distributed on the same section. In the agreed section, different layout forms are selected for the layout of the convergence base line according to the size of the excavation section, the clearance convergence of the single-line tunnel is generally laid according to a graph 4-2, and the clearance convergence of the communication channel is laid according to a graph 4-3.
When the measuring point is installed, a hole is drilled on the rock wall or the soil body of the section of the measured structure by a drilling machine or a percussion drill, the hole diameter is phi 40-phi 80mm, and the hole depth is 20 mm. And (3) filling the bar-planting glue in the hole, inserting the convergent embedded parts, enabling the axes of the two embedded parts to be in the baseline direction as much as possible, and monitoring after the bar-planting glue in the hole is solidified.
During monitoring, a convergence meter is adopted and arranged at one measuring point, and a movable buckle on the steel ruler is arranged at another monitoring point 6 opposite to the same observation section for measurement.
The horizontal convergence instrument is arranged on two monitoring points 6 on the same monitoring surface, and data acquisition is carried out through rough reading and fine reading on the horizontal convergence instrument. Attention is paid to temperature correction, namely, the temperature value at the time should be recorded simultaneously when the initial value is determined, the environmental temperature should be measured simultaneously every time convergence observation is carried out later, and the actually measured value at this time is the measured value of the instrument minus the temperature correction value. The measured value is compared with the initial value for convergence change.
As the temperature increases, the measured value will become smaller; when the temperature decreases, the measured value becomes large.
The correction calculation formula is as follows:
△LC＝K×△T×L
△ LC-temperature correction value (mm)
K-correction factor (12X 10-6 mm/DEG C is selected)
△ T-Change in temperature (. degree.C.)
L-measuring point distance (mm)
Surface subsidence monitoring
As shown in fig. 4-4, the arrangement of the monitoring points of the buried map of the surface subsidence monitoring points is as follows according to the requirements of the design drawing and the surface within the construction influence range: the ground surface settlement monitoring points are buried in a mode of manual excavation or drilling tool hole forming, and are required to penetrate through a pavement structure layer. And a protective cover is added at the measuring point, and the aperture is not less than 80 mm. The road and ground surface settlement monitoring measuring points are buried flatly, so that the influence on the passing of personnel and vehicles due to the unevenness is prevented, and meanwhile, the measuring points are buried stably, clear marks are made, and the protection is facilitated.
The surface subsidence measuring point is buried underground by adopting a mode of manual excavation or drilling tool pore-forming, and the burying steps are as follows:
a. excavating holes with the diameter of about 130mm and the depth of about 1m on the hard earth surface by using a Luoyang shovel, and tamping the bottoms of the holes;
b. removing residue soil, and injecting a proper amount of clear water into the hole for curing;
c. placing a steel bar mark with the length not less than 100cm in the center of the hole, exposing the filler surface by about 1-2 cm, and enabling the height of a measuring point to be lower than the height of a road surface so as to avoid the influence of a travelling crane on the measuring point, and backfilling and compacting by using coarse sand;
d. a steel protective cover is additionally arranged at the upper part, and the diameter of the protective cover is not less than 110 mm;
e. maintaining for more than 15 days.
Observation, calculation methods and requirements
The observation of the level monitoring network adopts a geometric leveling method, uses a precise level gauge to carry out observation,
the calculation method comprises the following steps: A. height difference between two points B: elevation HB of undetermined point B for hab (differential elevation-forward reading) is: HB-HA-hAB
Shield tunneling measurement
1. Composition of guide system
The guiding system mainly comprises a laser total station, an ELS laser system, a personal computer, a modem, a power supply, a PLC, an inclinometer, software and the like.
2. Measuring method
(1) Establishing a shield control point:
(2) measurement procedure
① after the shield is installed on site, measuring the coordinates of the shield control point in the engineering coordinate system;
② measuring the rotation angle and gradient of the shield by an inclinometer in ELS;
③ the basic size and measurement data of the shield are input into the DDJ-2S system, the laser total station is set on the measuring table, the DDJ-2S system is started, the system will automatically collect data every 30 seconds, the instant posture of the shield can be conveniently obtained through the software operation, or the three-dimensional coordinates of the shield cut and the shield tail can be calculated by the calculator, the three-dimensional coordinates are converted and inversely calculated by the three-dimensional coordinates, and compared with the design axis of the tunnel, the deviation value of the shield can be calculated, which is convenient for the shield operator to correct the propulsion parameters in time, and the propulsion axis of the shield is optimized.
(3) Measurement of duct piece position
After the propelling is finished, a gap value between the pipe piece and the shield tail is input, the extension value of the jack and the shield hinged state can be obtained through the PLC, and then the offset of the pipe piece and the design axis can be calculated. And by using NRG, stretching and other software, the three-dimensional coordinate of the circle center and the corresponding tunnel design coordinate can be calculated according to the measured three-dimensional coordinate of the formed duct piece, and finally the deviation value is calculated. The roundness of the formed pipe piece and the advance amount of the pipe piece can be seen from the report, and the ring forming quality of the pipe piece can be evaluated more specifically and truly.
(4) Shield attitude measurement
When the real-time attitude of the shield tunneling machine is measured, a characteristic point and a characteristic axis are measured, the notch center of the characteristic point is selected as the characteristic point, and the longitudinal axis of the characteristic point is selected as the characteristic axis. And controlling the azimuth angle of the longitudinal axis of the lead by using tunnel construction, wherein the difference between the azimuth angle and the azimuth angle of the shield is an azimuth angle correction value, and correcting the shield tunneling direction according to the azimuth angle correction value.
(5) Lining ring segment measurement
Lining ring segment measurements include measuring ring center deviation of the lining ring, ovality of the ring, and attitude of the ring. And measuring the lining ring piece for at least 3-5 rings once, wherein each ring is 1.5m, each ring is measured during measurement, and the front end face of the ring to be measured is measured. And 5, overlapping and measuring ring sheets when measuring adjacent lining rings. The allowable error of the ring plate plane and elevation measurement is +/-15 mm. After the shield measurement data is arranged, shield operators are reported in time.
Control reference and alarm value
The monitoring and early warning are one of the purposes of monitoring work and are important measures for preventing engineering accidents and ensuring the safety of engineering structures and surrounding environments. The monitoring control value and the early warning value are the precondition for implementing the monitoring work and are important bases for judging whether the engineering structure and the surrounding environment are in normal, abnormal and dangerous states during the monitoring period, so that the monitoring control value and the warning value are determined necessarily. The monitoring control value and the alarm value are commonly controlled by two indexes of a monitoring variable accumulated value and a change rate.
The monitoring control values and alarm values adopted in the project are as follows:
Claims (10)
1. a construction method for a tunnel shield zone lower penetrating and winding city comprises the following steps:
step 1: tunneling a test section;
step 2: formally tunneling;
and step 3: mounting a duct piece;
and 4, step 4: grouting;
and 5: monitoring and adjusting;
the step 1 comprises the following steps:
determining shield propulsion parameters: setting the pressure of a soil bin of the shield machine to be more than 0.6-0.8bar, the tunneling propulsion speed to be 25-35mm/min, the rotating speed of a cutter head to be less than 1.1 r/min, controlling the stratum loss rate to be within 2 percent, and controlling the shield propulsion pressure to be not less than 0.8 time of the water and soil pressure; grouting synchronously during tunneling;
determining grouting pressure and grouting amount: the grouting amount of each ring is 120-150% of the building gap; the synchronous grouting amount is not less than 5.0m per pushing ring3；
Determining the pressure of secondary slurry supplement, wherein the secondary slurry supplement adopts double-fluid slurry or a shield machine with a plunger pump; and (4) injecting the slurry once in each ring when the shield passes through the risk zone, wherein the pressure of the slurry injected each time is 0.3-0.5 Mpa.
2. The tunneling shield zone under-crossing city construction method according to claim 1, wherein the step 2 of formal tunneling comprises:
determining the range of crossing the city-surrounding highway: the distance between a cutter head of the shield machine and the roadbed is 15m, and the distance between a shield tail and the roadbed is 15 m;
and determining the tunneling soil pressure as follows: the soil pressure fluctuation is within 0.1bar, and the foam soft soil pressure is used in cooperation;
determining the tunneling soil output: the soil output is uniformly controlled according to the footage and the soil pressure in the shield tunneling process, the soil output is matched with the grouting amount, and the soil output is as follows: the muck truck is filled to about 18m3Pushing the soil output of 1.5 m;
determining a hinging device reasonably using the shield, and controlling the shield tunneling axis: calculating the turning angle of each step of shield middle folding according to the deviation degree of the shield, firstly opening a profiling cutter of the shield to carry out over-excavation construction, wherein the over-excavation length is from half to one shield body of the shield, then adjusting a shield middle folding device according to the calculation, then assisting in jack marshalling and partition oil pressure control to carry out tunneling construction, and adjusting the turning angle at any time according to the shield posture data during advancing until the shield machine returns to the design axis.
3. The tunneling shield zone down-through city construction method according to claim 1, wherein the step 3 segment installation comprises: controlling the installation quality of the duct piece: firstly, measuring the shield tail, and then selecting the K block position according to the stroke of the oil cylinder, the parameters provided by the measuring system and the track and trend.
4. The tunneling construction method for the underground city penetrating and surrounding under the shield zone according to claim 1, wherein the grouting in the step 4 comprises synchronous grouting and second and third grout supplement: adjusting the proportion and the grouting mode of grouting to control the initial setting time within 8 hours, wherein the grouting material is pure cement slurry with the weight ratio of water to cement being 1: 1; performing secondary slurry filling after the wall on the pipe piece outside the 5 rings at the rear part of the shield tail; and the third-time slurry supplement is to reserve a grouting hole at the top of each ring of pipe piece and install a grouting plug for grouting from the middle part or the tail part of the shield tunneling machine, wherein the grouting slurry is cement and water glass double-liquid mixed slurry.
5. The tunneling construction method according to claim 1, further comprising: after the shield machine is shut down, injecting a proper amount of foam and thick bentonite slurry into the cutter head and the soil bin, wherein the bentonite slurry is proportioned with water in parts by weight: the soil is 700: 300; and (3) the bentonite slurry is injected into the soil bin with the average soil pressure of more than 1.5bar so as to maintain the water and soil pressure balance of the whole excavation surface.
6. The tunneling shield zone down-through city construction method according to claim 5, further comprising: in the shield crossing process, a left line shield carries out wall back grouting holes on corresponding duct pieces, after grouting floral tubes are inserted into walls, deep hole grouting is carried out on the periphery of the interval structure through the wall back grouting holes, grouting amount and grouting pressure are synchronized, unconfined uniaxial compressive strength is greater than 1MPa, and large-range deep hole grouting adjustment grouting pressure ensures that effective diffusion radius is greater than 0.5 m.
7. The tunneling construction method according to claim 1, wherein the step 5 of monitoring and adjusting further comprises: the method for observing the duct piece settlement comprises the following steps: the settlement and convergence monitoring points of the segment structure are 1 point distributed for the number not exceeding every 5 rings, and measuring points are arranged on segments of the side line of the tunnel ballast bed:
the duct piece settlement monitoring method comprises the following steps: and leveling base points for vault settlement are distributed in or outside the hole, a reinforcing steel bar with the diameter of 6mm is bent into a triangle, the triangle is fixed at the vault part on the side to be measured, leveling measurement is carried out by an electronic leveling instrument footfall method, and the elevation of a settlement point is measured.
8. The tunneling construction method according to claim 1, wherein the step 5 of monitoring and adjusting further comprises: shield tunnel clearance convergence monitoring: the empty convergent measuring points and the structural vault settlement cloth are distributed on the same section; the method comprises the following steps of arranging clearance convergence of a single-wire tunnel and clearance convergence of a communication channel; a point distribution principle: the net hole depth is 20mm, the convergent embedded parts are inserted after the bar planting glue is filled in the hole, the axes of the two embedded parts are in the base line direction, and monitoring can be carried out when the bar planting glue in the hole is solidified; and (5) measuring by using a convergence meter and combining temperature monitoring.
9. The tunneling construction method according to claim 1, wherein the step 5 of monitoring and adjusting further comprises: monitoring the surface settlement, wherein the monitoring point arrangement principle is as follows: burying a ground surface settlement monitoring point requiring penetration of a pavement structure layer; the measuring point is provided with a protective cover, the aperture is larger than or equal to 80mm, and the embedding method comprises the following steps: excavating holes with the diameter of about 130mm and the depth of about 1m on the soil surface, and tamping the bottoms of the holes; removing residue soil, and injecting a proper amount of clear water into the hole for curing; placing a steel bar mark with the length not less than 100cm in the center of the hole, exposing the filler surface by about 1-2 cm, and backfilling and tamping coarse sand, wherein the height of a measuring point is lower than the height of a road surface; a steel protective cover with the diameter not less than 110mm is additionally arranged at the upper part; maintaining for more than 15 days.
10. The tunneling construction method according to claim 1, wherein the step 5 of monitoring and adjusting further comprises: performing shield tunneling measurement, establishing a shield control point, and establishing the control point at an immovable position of a shield; after the shield is installed on site, measuring the coordinates of the shield control point in the engineering coordinate system; measuring the rotation angle and the gradient of the shield by an inclinometer in the ELS; inputting the basic size and the measurement data of the shield into a DDJ-2S system, arranging a laser total station on a measuring table, and starting the DDJ-2S system, so that the system can automatically acquire data every 30 seconds;
measuring the position of the duct piece: after the propelling is finished, inputting a gap value between the pipe piece and the shield tail, obtaining an extension value of the jack and a shield hinging state through the PLC, and calculating the offset of the pipe piece and a design axis; calculating the three-dimensional coordinate of the circle center and the corresponding tunnel design coordinate according to the measured three-dimensional coordinate of the formed segment, and finally calculating a deviation value;
and (3) measuring the shield attitude: measuring a characteristic point and a characteristic axis when the real-time attitude of the shield tunneling machine is measured, selecting the center of a notch of the shield tunneling machine as the characteristic point, and selecting a longitudinal axis of the shield tunneling machine as the characteristic axis; the azimuth angle of the longitudinal axis of the guide line is controlled by using tunnel construction, and the difference between the azimuth angle and the azimuth angle of the shield is an azimuth angle correction value, so that the shield tunneling direction is corrected;
and (3) measuring lining ring pieces: measuring the ring center deviation of the lining ring, the ovality of the ring and the posture of the ring; measuring the lining ring piece for at least 3-5 rings, wherein each ring is 1.5m, measuring each ring during measurement, and measuring the front end face of the ring to be measured; and 5, overlapping and measuring ring sheets when measuring adjacent lining rings.
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Cited By (6)
| Publication number | Priority date | Publication date | Assignee | Title |
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| CN111706341A (en) * | 2020-06-30 | 2020-09-25 | 郑州地铁集团有限公司 | Construction method for soil pressure balance shield to penetrate large-diameter sewage main pipe downwards |
| CN112031794A (en) * | 2020-09-11 | 2020-12-04 | 中铁四局集团第二工程有限公司 | Shield receiving construction method for approaching existing subway operation line in water-rich silt stratum |
| CN112483187A (en) * | 2021-01-29 | 2021-03-12 | 中铁工程装备集团有限公司 | Shield tunneling machine pipe piece settlement monitoring system and monitoring method |
| CN112554913A (en) * | 2020-12-11 | 2021-03-26 | 中铁二十局集团第四工程有限公司 | Reinforcing method for underground crossing channel under shield |
| CN112727470A (en) * | 2020-12-31 | 2021-04-30 | 中铁建大桥工程局集团第二工程有限公司 | Construction reinforcing method for shield tunnel at overlapped section |
| CN115235416A (en) * | 2022-06-16 | 2022-10-25 | 上海隧道工程有限公司 | Automatic monitoring system and method for shield construction segment settlement |
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2020
- 2020-01-10 CN CN202010027193.5A patent/CN111101958A/en active Pending
Cited By (7)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN111706341A (en) * | 2020-06-30 | 2020-09-25 | 郑州地铁集团有限公司 | Construction method for soil pressure balance shield to penetrate large-diameter sewage main pipe downwards |
| CN112031794A (en) * | 2020-09-11 | 2020-12-04 | 中铁四局集团第二工程有限公司 | Shield receiving construction method for approaching existing subway operation line in water-rich silt stratum |
| CN112554913A (en) * | 2020-12-11 | 2021-03-26 | 中铁二十局集团第四工程有限公司 | Reinforcing method for underground crossing channel under shield |
| CN112727470A (en) * | 2020-12-31 | 2021-04-30 | 中铁建大桥工程局集团第二工程有限公司 | Construction reinforcing method for shield tunnel at overlapped section |
| CN112483187A (en) * | 2021-01-29 | 2021-03-12 | 中铁工程装备集团有限公司 | Shield tunneling machine pipe piece settlement monitoring system and monitoring method |
| CN115235416A (en) * | 2022-06-16 | 2022-10-25 | 上海隧道工程有限公司 | Automatic monitoring system and method for shield construction segment settlement |
| CN115235416B (en) * | 2022-06-16 | 2023-10-13 | 上海隧道工程有限公司 | Automatic monitoring system and method for shield construction segment settlement |
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