Post-wall grouting for shield construction

1. Classification of post-wall grouting

【Formula】Two steps to block the water

The post-segment wall grouting can be divided into synchronous grouting and water plugging grouting according to the difference in the time and purpose of the shield advancement.

2. The role of synchronous grouting

【Formula】Fill the brace to prevent collapse control

Synchronous grouting is carried out at the same time as the shield tunneling, which is carried out at the same time as the shield is advanced and the shield tail gap is formed through the synchronous grouting system. The slurry plays a timely filling role at the moment of the formation of the gap at the tail of the shield, so that the surrounding soil can be supported in time, which can effectively prevent the collapse of the rock mass and control the settlement of the surface.

3. The role of secondary grouting

【Formula】Stop water and reinforce the soil

The secondary reinforcing grouting behind the segment is to carry out reinforcing grouting behind the segment through the hoisting hole of the segment (supplementing part of the unfilled cavity and improving the compactness of the soil behind the segment) after the end of synchronous grouting to improve the effect of synchronous grouting. The grout filling time of secondary grouting should lag behind the excavation for a period of time, which plays a role in reinforcing and stopping water for the soil around the tunnel.

4. The role of water plugging and grouting

【Formula】Water-rich waterproof compactness

In order to improve the waterproofness and compactness of the backing grouting layer, the influence of groundwater and the consolidation rate of the grouting in the early stage of grouting is considered in the water-rich area, and the water plugging grouting is carried out after the secondary grouting when necessary.

5. Basis for the selection of grouting method

【Formula】The geological surface ring requires the performance of the equipment

The grouting method is selected according to the engineering geological conditions, surface settlement state, environmental requirements and equipment performance.

6. The purpose of grouting behind the wall

【Formula】Durable reinforcing layer, early support to prevent uncontrollable sinking, fast strength without support and early stability

(1) Establish the support system of the grouting body as soon as possible in the annular void between the segment and the surrounding rock, prevent the formation loss caused by the collapse of the soil around the tunnel and the loss of groundwater, and control the ground settlement value.

(2) The consolidation strength of the grouting body is obtained as soon as possible to ensure the early stability of the initial lining structure of the segment, and to prevent the displacement and deformation of the segment from being in the grout environment without supporting force behind the long-distance segment lining.

(3) As a reinforcing layer of tunnel lining structure, it has durability and certain strength. The filled grouting body isolates the groundwater from the segment, avoids or greatly reduces the opportunity for groundwater to be in direct contact with the segment, thus becoming the protective layer of the segment, avoiding or slowing down the erosion of groundwater to the segment, and improving the durability of the lining structure.

7. Selection of grouting materials

【Formula】Authentic ring

Single-liquid or double-liquid grouting materials can be selected according to geological conditions, tunnel conditions and surrounding environmental conditions.

8. Performance parameters of grouting materials

【Formula】Condensation environmental protection strong current charge

The strength, fluidity, fillability, setting time, shrinkage and environmental protection of the grouting material should meet the construction requirements.

9. Grouting parameters

【Formula】Measure the pressure speed, charge coefficient

(3) The synchronous grouting process should be controlled according to the grouting amount and grouting pressure, and the grouting speed should be determined according to the grouting amount and tunneling speed.

(5) The filling coefficient of synchronous grouting should be determined according to the formation conditions, construction status and environmental requirements, and the filling coefficient should be 1.30~2.50.

10. Basis for determining synchronous grouting pressure

【Formula】Prepare for buried pipe grouting

The grouting pressure should be determined according to factors such as geological conditions, grouting methods, segment strength, equipment performance, grout characteristics and tunnel depth.

11. Basis for determining the secondary grouting pressure

【Formula】Ring bar sinking monitoring

The grouting amount and grouting pressure of secondary grouting should be determined according to environmental conditions and settlement monitoring results.

12. Slurry regulations

【Formula】Seven properties of mixing, pressing, and transportation, and miscellaneous are easy to dense and condense and condense strongly

1) The slurry should be mixed according to the design and construction mix ratio.

2) The relative density, consistency, workability, maximum particle size of sundries, coagulation time, strength after condensation and solidification shrinkage of slurry should meet the engineering requirements.

3) After mixing, the slurry should be easy to press, and should not be segregated and precipitated during transportation.

13. Key points of grouting construction behind the wall

【Formula】Prepare for the inspection worker, transfer and clear the seal

(1) Before grouting, the mixing, storage, transportation and grouting equipment should be prepared according to the grouting construction requirements, and the trial operation should be carried out.

(2) Before grouting, the grouting holes, grouting pipelines and equipment should be inspected.

(4) Reasonably formulate the process of grouting behind the wall, and adjust the grouting parameters according to the grouting effect.

(5) It is advisable to be equipped with an instrument that automatically records parameters such as grouting amount, grouting pressure and grouting time.

(6) The grouting operation should be carried out continuously. After the operation, the grouting equipment and pipelines should be cleaned in time.

(7) After the segment grouting port is used, the grouting port should be blocked.

14. Basis and method of shield attitude adjustment

【Formula】Horizontal and vertical bias rolling, super digging reverse

According to the lateral and vertical deviation and roll angle of the shield, the attitude of the shield can be adjusted by means of hydraulic cylinder group control or the use of a profiler cutter to overdig or reverse the cutterhead.

Yesterday 速记口诀5/14

1. Segment assembly method

Choose to fight the top and tighten it

2. True circle retains meaning

Reduce sedimentation, keep sperm and speed up

3. Key points of segment assembly construction

Clear and control to prevent losses, spot check the empty push water

Three days ago, shorthand mantra 5/12

1. Stress management

The upper and lower limits of the method, the calculation of the variable row torsion

2. Discharge management

Pressing and digging are managed together, and the bulk weight platform is transferred

3. Improve the characteristics of the muck

The plastic flow is viscous and low force

4. Improve the material of the muck

Foam bulking pulp

5. Key points of earth pressure balance shield tunneling

The warehouse is full of soil leveling, and the supervision and supervision are set up to regulate and control well

Seven days ago, shorthand mantra 5/8

1. The purpose of foundation pit foundation reinforcement

Stop water and reduce the main force, and reduce the protection and prevention

2. The plane layout form of foundation reinforcement

The pier edge is full

3. Common methods of foundation reinforcement

Replace the shallow lifting force, stir deep and strong resistance

4. The depth range of foundation pit foundation reinforcement

Two bottoms under the surface

5. Grouting method

There is seam penetration, seamless splitting, medium sand, clay can be compacted

6. Grouting slurry

Solid coagulation suspends the main dissolved sludge

7. Grouting process parameters

Flow orifice pressure enclosure formulation

8. Grouting inspection

Standard static contact surface, 28d uniform strength/seepage test

9. The cement-soil mixing method is suitable for

Sand powder sticky yellow soft pigment filling

10. The cement-soil mixing method is not suitable for soil quality

Lonely and unsoft and hard sticky, dense sand and water powder rot test

11. Technical advantages of cement-soil mixing method to strengthen soft soil

The price of earth and steel, the noise of solid pollution

12. The main steps of spraying and stirring

Flat pre-stirring spray and stop

13. Construction quality inspection of cement-soil mixing pile

The uniform diameter of the hitch shaft is deep

14. Scope of application of high-pressure jet grouting method

The sand powder is clay and yellow, and the plain is filled with gravel soil

15. Test the soil quality by high-pressure jet grouting method

Hard sticky organic yellow collaps

16. High-pressure jet grouting method and consolidated body shape

Fixed wall swing fan spin cylinder

17. High-pressure injection medium and method

Both gas and water are made of mud

18. Construction parameters of high-pressure jet grouting

20 water slurry water-cement ratio

19. High-pressure jet grouting process

Drill into the jet lever in place

20. Factors affecting the diameter of the solid added by jet spraying

Art pressure rises speed soil

21. High-pressure jet grouting construction quality inspection

Standard through the drill core dynamic touch digging

Two weeks agoShorthand mantra 5/1

1. Track (commonly known as line) structure

The rail is connected to the sleeper, and the bed is attached

2. The role of track structure

Guided bearer transmission foundation

3. Requirements for track structure

Strong and stable for a long time, the noise surface is smooth

4. Characteristics of track structure

Vibration damping, low dimensional strength, high insulation of curved rails

5. Wheel type

Positive and auxiliary fields, distance overshift

6. Track bed and sleeper

The long tunnel bridge is U high, the ground station in the library, and the long and short pillows are the whole bed

7. Vibration damping structure

Generally, seamless bullet deduction, high vibration buckle short trampoline, special floating plate whole bed

8. The role of sound barriers

Blocking direct blocking transatterioration diffraction

9. Types of sound barriers

Expansion and reverse vibration absorption active drop, straight folding table tilt semi-completely closed, LTY arc deer

五周前速记口诀4/11

1. Types of prestressed tendons

The silk thread is the same as the sticky batch

2. Prestressed tendon approach inspection

The standard specification of the certificate package is repeated and re-extracted one by one

3. Precautions for transportation, storage and construction operation of prestressed tendons

Clean and avoid the winch warehouse put 3

4. The cutting length of the prestressed tendon is determined

The anchor top of the hole seat is exposed and long, and the cold tension is reserved.

5. Production of prestressed tendons

There are multiple cutting upsets

6. Pipes for prestressed rib holes

The golden snail plastic wave bends the inner light, strong and rigid force transmission without slurry leakage

7. Other requirements for pipe (hole) channel

Area ratio of steel polywall thickness

8. Pipeline entry acceptance

Check the check lot

9. Post-tensioned prestressed anchors and connectors are classified according to the anchoring method

Grip the cast clips

10. Basic requirements for anchors, clamps and connectors

The fouling and rust are cracked by a single root, and the anchoring force is suitable for low grading

11. Anchor backing plate requirements

Steel-cast bell tendons are irrigated

12. Anchors, fixtures and connectors are required to enter the site for acceptance

Batch check and verify, and the number of drawings is qualified