Synchronous slag removal equipment for positive and negative circulation of diaphragm wall and construction method

Abstract

The invention relates to diaphragm wall positive and negative circulation synchronous slag removal equipment which comprises a new slurry pool, a circulation slurry pool, a slurry making pool and a waste slurry pool, and fresh slurry is stored in the new slurry pool and used for injecting the fresh slurry into a diaphragm wall groove; the circulating pulp tank is used for supplementing pulp; the slurry making pool is used for making fresh slurry and injecting the fresh slurry into the new slurry pool; the waste slurry tank is used for extracting waste slurry in the diaphragm wall groove; the new slurry pool is connected with a slurry suction opening of the direct circulation grouting pump through a pipeline, and the direct circulation grouting pump is connected with the first guide pipe. Fresh slurry is injected into the diaphragm wall groove; a grouting pump is arranged at one end of the top of the diaphragm wall groove and is connected with the circulating slurry pool through a pipeline; a slurry suction pump is arranged at the other end of the diaphragm wall groove top and is connected with a waste slurry pool through a pipeline; the waste slurry tank is connected with a slurry outlet of the reverse circulation slurry suction pump through a pipeline, and the reverse circulation slurry suction pump is connected with the second guide pipe to pump waste slurry into the waste slurry tank. And the utilization rate of the slurry is increased by recycling the treated slurry stored in the slurry pool.

Description

Technical Field

[0001] The present invention relates to the technical field of ground-connected wall construction, and in particular to synchronous slag clearing equipment and a construction method for a ground-connected wall with forward and reverse circulation. Background Art

[0002] In recent years, with the continuous advancement of urbanization, various large-scale infrastructure construction projects have continued to increase, such as high-rise buildings, subways, and underground integrated pipe corridors. These projects have extremely high requirements for the stability and safety of underground structures. As an effective form of underground retaining structure, ground-connected walls are widely used in these large-scale infrastructure construction projects. With the development and application of ground-connected walls, the requirements for the quality of ground-connected walls are also increasing. A large amount of ground-connected wall test data shows that excessive thickness of sediment at the bottom of the trench is one of the main factors affecting the quality of the wall.

[0003] In recent years, construction technology has been greatly improved, and the trenching process of ground-connected walls has become relatively mature. However, the problem of sediment control has become increasingly prominent. The traditional ground-connected wall slag cleaning method mainly adopts a single positive circulation or reverse circulation hole cleaning method, which has low slag cleaning efficiency and poor effect, and it is difficult to meet the requirements of rapid construction. During positive circulation hole cleaning, the ability of the mud to carry waste slag is limited, and it is easy to leave a lot of waste slag at the bottom of the hole. Especially for ground-connected walls over 50m, the effect of positive circulation hole cleaning is very small. Although reverse circulation hole cleaning improves the slag cleaning effect to a certain extent, due to the large bottom area of ​​the ground wall trench, the high viscosity and poor fluidity of the sediment, the reverse circulation can often only clean the slag thoroughly locally. The slag cleaning effect is poor in areas far away from the conduit or close to the trench wall, and the required hole cleaning time is too long, which may even cause the hole to collapse and become thicker as it is cleaned.

[0004] Therefore, it becomes increasingly important to further improve the construction technology, enhance the slag removal effect of the ground-anchored wall, and improve the quality of the ground-anchored wall.

[0005] In view of this, after a large number of experimental verifications, the present invention proposes a positive and reverse circulation synchronous slag cleaning equipment and construction method for a ground-connected wall. Summary of the invention

[0006] To this end, the second aspect of the present invention discloses a synchronous slag cleaning device for forward and reverse circulation of ground-connected wall, comprising a new slurry pool, a circulating slurry pool, a slurry making pool and a waste slurry pool, wherein the new slurry pool stores fresh slurry for injecting fresh slurry into the ground-connected wall groove; the circulating slurry pool is used for slurry replenishment; the slurry making pool is used for making fresh slurry and injecting it into the new slurry pool; the waste slurry pool is used for extracting waste slurry in the ground-connected wall groove;

[0007] The new slurry pool is connected to the slurry suction port of the positive circulation grouting pump through a pipeline, and the positive circulation grouting pump is connected to the first conduit; fresh slurry is injected into the ground-connected wall groove; a grouting pump is provided at one end of the top of the ground-connected wall groove, and the grouting pump is connected to the circulating slurry pool through a pipeline; a slurry suction pump is provided at the other end of the top of the ground-connected wall groove, and the slurry suction pump is connected to the waste slurry pool through a pipeline; the waste slurry pool is connected to the slurry outlet of the reverse circulation suction slurry pump through a pipeline, and the reverse circulation suction slurry pump is connected to the second conduit to pump the waste slurry to the waste slurry pool.

[0008] The second aspect of the present invention discloses a synchronous slag removal construction method for a ground-connected wall with positive and negative circulation, using the synchronous slag removal equipment for a ground-connected wall with positive and negative circulation as described in the first aspect, comprising the following steps:

[0009] S1: Based on the parameter characteristics of the ground-connected wall, calculate the head and flow rate of the positive circulation grouting pump and the reverse circulation grouting pump;

[0010] S2: Based on the head and flow of the positive circulation grouting pump and the reverse circulation grouting pump, match the model of the synchronous slag cleaning equipment and complete the equipment installation;

[0011] S3: Based on the change of the slurry level in the ground-connected wall groove, the start and stop of the new slurry pool, the circulating slurry pool, the slurry pool and the waste slurry pool are controlled to complete the slag removal operation;

[0012] S4: Replace the positive circulation grouting pump with the reverse circulation grouting pump, and execute S3 again;

[0013] S5: Determine whether the sediment index of the ground-connected wall groove meets the specification; if not, return to step S3; otherwise, enter step S6;

[0014] S6: Equipment removal and concrete pouring funnel.

[0015] Furthermore, the head selection of the positive circulation grouting pump in S1 satisfies the following:

[0016] H≥k×(z+hw)

[0017] Among them, H is the design value of the pump head, z is the head height, that is, the sum of the elevation difference from the water surface at the inlet to the water surface at the outlet and 1 / 10 of the length of the pipeline from the inlet to the outlet, hw is the head loss, and k is the head experience coefficient.

[0018] Furthermore, the flow selection of the positive circulation grouting pump in S1 should meet the following requirements:

[0019] When the bottom of the diaphragm wall is a hard rock layer: Q ≥ hab / 6, P = ηρvh > c, where

[0020] When the bottom of the diaphragm wall is a soft soil layer: 2.0c<P=ηρvh>c, where

[0021] If the bottom of the ground-connected wall trench is a sand layer: 1.5c<P=ηρvh>c, where

[0022] Among them, Q is the flow rate, h is the height of the ground-connected wall, a is the thickness of the ground-connected wall, b is the width of the ground-connected wall, P is the dynamic water pressure of the grouting liquid to the edge of the groove, η is the flow rate empirical coefficient, ρ is the density of the grouting slurry, v is the flow velocity at the outlet, and c is the cohesion of the sediment, which is obtained by experiment.

[0023] Furthermore, the head selection of the reverse circulation slurry suction pump in S1 should meet the requirements of the following empirical formula:

[0024] H ≥ k × z

[0025] Among them, H is the design value of the pump head, z is the head height, that is, the elevation difference between the water surface at the inlet and the water surface at the outlet, that is, the length of the conduit.

[0026] Furthermore, the flow selection of the positive circulation grouting pump in S1 should meet the following requirements:

[0027] When the bottom of the local diaphragm groove is a hard rock layer: Q ≥ hab / 6, P = ηρvh > c, where

[0028] When the bottom of the local diaphragm trench is a soft soil layer: 2.0c<P=ηρvh>c, where

[0029] When the bottom of the local ditch is a sand layer: 1.5c<P=ηρvh>c, where

[0030] Among them, Q is the flow rate, h is the height of the ground-connected wall, a is the thickness of the ground-connected wall, b is the width of the ground-connected wall, η is the flow rate empirical coefficient, ρ is the density of the grouting slurry, v is the flow velocity at the outlet, and c is the cohesion of the sediment obtained by experiment.

[0031] Furthermore, the first conduit and the second conduit in S2 should be conduits for concrete casting, with an inner diameter of not less than 250 and not less than 1 / 4 of the groove width. A watertightness test should be carried out before installation, and the requirements of the watertightness test should be:

[0032] Assemble the conduit and seal both ends with steel plate welding;

[0033] Inject water, the amount of water injected is greater than 70% of the total volume of the sealed conduit;

[0034] Pressurize, add air with an air compressor to the calculated pressure value P1; the pressure value P1 is calculated as follows:

[0035] P1≥1.5gh and P1≥24h1-12h2;

[0036] Among them, P1 is the pressure value injected by the air compressor, h is the height of the ground-connected wall, h1 is the length of the conduit, and h2 is the depth of the mud in the trench.

[0037] Furthermore, the grouting pump and suction pump in S3 use equipment with a flow rate Q greater than 15m3 / h and a lift H greater than 20m, and the liquid level in the ground-connected wall groove should be more than 0.5m higher than the groundwater level.

[0038] Furthermore, the slag cleaning operation of S3 specifically includes steps S31-S33;

[0039] Step S31, obtaining vibration data and calculating standardized vibration intensity based on soil layer type;

[0040] Step S32, calculating the vibration influence factor and the liquid level influence factor;

[0041] Step S33, adjusting the head empirical coefficient and the flow empirical coefficient respectively based on the vibration influence factor and the liquid level influence factor.

[0042] Furthermore, the vibration intensity V is as follows:

[0043]

[0044] Where a(t) is the vibration acceleration, t represents time, and T is the monitoring period;

[0045] Standardized vibration intensity V n As shown below:

[0046]

[0047] Among them, V m is the vibration intensity threshold of the soil layer;

[0048] The vibration influence factor and liquid level influence factor are shown in the following formula:

[0049]

[0050] f h =1+k h |Δh|

[0051] Among them, f v With f h are vibration influence factor and liquid level influence factor, respectively, k v is the vibration sensitivity coefficient, k h is the liquid level change sensitivity coefficient, Δh is the liquid level change rate;

[0052] The head experience coefficient k and flow rate experience coefficient η are shown as follows:

[0053] k=u1×(f v -1)+(1-u1)×(f h -1)

[0054] η=u2×(f v -1)+(1-u2)×(f h -1)

[0055] Among them, u1 and u2 are empirical parameters.

[0056] Compared with the prior art, the present invention has the following beneficial effects:

[0057] The present invention proposes a synchronous slag cleaning device and construction method for positive and reverse circulation of a ground-connected wall. The positive and reverse circulation synchronous slag cleaning not only reduces the limitations of the single circulation mode in the traditional method, but also can more comprehensively and effectively clean the sediment at the bottom of the ground-connected wall trench, especially can remove the sediment at different positions on the bottom of the trench, avoiding the situation where the sediment is not thoroughly cleaned in some areas; by simultaneously starting the positive circulation grouting pump and the reverse circulation grouting pump, the sediment can be cleaned efficiently and the slag cleaning time can be significantly shortened. Compared with the traditional single slag removal method, this method can significantly improve the operation speed, reduce the construction period, and promote the construction progress; through two slag removal and transposition operations, it ensures that the sediment at the bottom of the ground-connected wall groove is completely removed, avoiding the problem of unqualified subsequent construction quality caused by the sediment not being cleaned up, thereby improving the quality of the ground-connected wall; the use of accurately calculated grouting pump and suction pump flow and head configuration ensures the reasonable fluidity of the mud during construction and the effective removal of sediment, avoiding the risk of excessive flow causing the groove wall to collapse or damage; by recycling the mud stored in the mud pool after treatment, the utilization rate of the mud is improved, the use of new slurry is reduced, and the construction cost is reduced. In addition, the present invention reveals the vibration coupling and fatigue effects of the pump system under different soil layers (hard rock, soft soil, sand layer), and by introducing the quantitative coupling parameters of the head and flow rate formula, the optimized design and early warning of vibration abnormalities are realized, the stability of the groove wall is improved, and the equipment life is extended. By optimizing the frequency coordination and flow control of the grouting pump and the suction pump, the disturbance of the vibration coupling effect on the ground-connected wall groove wall is significantly reduced, and the stability of the groove wall is enhanced. In addition, by combining the formula analysis of head and flow rate, accurate working parameter matching between the pump and the pipeline is achieved, effectively suppressing the impact of pressure pulsation, improving the durability and operating stability of the equipment, and thus reducing losses caused by seal failure and equipment aging. BRIEF DESCRIPTION OF THE DRAWINGS

[0058] Figure 1 It is a schematic diagram of the first slag cleaning of the synchronous slag cleaning equipment of the ground-connected wall with positive and reverse circulation of the present invention;

[0059] Figure 2It is a schematic diagram of the second slag cleaning of the synchronous slag cleaning equipment of the ground-connected wall with positive and reverse circulation of the present invention;

[0060] Figure 3 It is a schematic diagram of the synchronous slag removal equipment of the forward and reverse circulation of the ground-connected wall of the present invention after removal and before concrete pouring;

[0061] Figure 4 This is a flow chart of the synchronous slag removal construction method for positive and reverse circulation of the ground-anchored wall.

[0062] Explanation of the reference numerals: 1. Positive circulation grouting pump; 2. Reverse circulation suction grouting pump; 3. First conduit; 4. Second conduit; 5. Grouting pump; 6. Suction grouting pump; 7. New slurry pool; 8. Circulating slurry pool; 9. Slurry making pool; 10. Waste slurry pool; 11. Ground-connected wall groove. DETAILED DESCRIPTION

[0063] In order to make the objects and advantages of the present invention more clearly understood, the present invention is further described below in conjunction with embodiments.

[0064] The present invention first discloses a synchronous slag cleaning device for positive and negative circulation of ground-connected walls, such as Figure 1 As shown, it includes a new slurry pool 7, a circulating slurry pool 8, a slurry making pool 9 and a waste slurry pool 10. The new slurry pool 7 stores fresh slurry for injecting the fresh slurry into the ground-connected wall groove 11; the circulating slurry pool 8 is used for replenishing slurry; the slurry making pool 9 is used to make fresh slurry and inject it into the new slurry pool 7; and the waste slurry pool 10 is used to extract the waste slurry in the ground-connected wall groove 11.

[0065] More specifically, the new slurry pool 7 is connected to the slurry suction port of the positive circulation grouting pump 1 through a pipeline, and the positive circulation grouting pump 1 is connected to the first conduit 3; fresh slurry is injected into the ground-connected wall groove 11; a grouting pump 5 is provided at one end of the top of the ground-connected wall groove 11, and the grouting pump 5 is connected to the circulating slurry pool 8 through a pipeline; a slurry suction pump 6 is provided at the other end of the top of the ground-connected wall groove 11, and the slurry suction pump 6 is connected to the waste slurry pool 10 through a pipeline; the waste slurry pool 10 is connected to the slurry outlet of the reverse circulation slurry suction pump 2 through a pipeline, and the reverse circulation slurry suction pump 2 is connected to the second conduit to pump the waste slurry to the waste slurry pool 10.

[0066] The present invention further discloses a synchronous slag removal construction method for a ground-connected wall with positive and negative circulation, such as Figure 4 As shown, steps S1-S6 are included.

[0067] S1: Based on the parameter characteristics of the ground-connected wall, the head and flow rate of the positive circulation grouting pump 1 and the reverse circulation grouting pump 2 are calculated.

[0068] The parameter characteristics of the ground-anchored wall include but are not limited to: hole depth, groove width, width, conduit diameter, density of grouting slurry, and cohesion of sediment.

[0069] S2: Based on the head and flow of the positive circulation grouting pump 1 and the reverse circulation grouting pump 2, match the model of the synchronous slag cleaning equipment and complete the equipment installation.

[0070] The installation process of the equipment specifically includes: after the steel cage of the local wall groove 11 is lowered into place, the conduits 3 and 4 are vertically installed in the groove using a special conduit rack, and at the same time, the distance between the first conduit 3 and the second conduit 4 and the bottom of the groove is controlled to be within the range of 300-500mm, and the grouting port of the positive circulation grouting pump 1 is tightly connected to the first conduit 3 using a pipe connector with good sealing performance, and the grouting port of the reverse circulation grouting pump 2 is tightly connected to the second conduit 4, and at the same time, the grouting port of the positive circulation grouting pump 1 is connected to the new slurry pool 7 through a pipeline; the slurry outlet of the reverse circulation grouting pump 2 is connected to the waste slurry pool 10.

[0071] S3: Based on the change of the slurry level in the ground-connected wall groove 11, the start and stop of the new slurry pool 7, the circulating slurry pool 8, the slurry pool 9 and the waste slurry pool 10 are controlled to complete the slag cleaning operation.

[0072] Specifically, the positive circulation grouting pump 1 and the reverse circulation grouting pump 2 are started at the same time to start the slag cleaning operation, and the liquid level sensor is used to monitor the change of the mud liquid level in the ground connection wall groove 11 in real time: if the mud liquid level drops to less than the preset mud liquid level lower limit threshold, it is determined that the amount of mud in the groove is insufficient, and the grouting pump 5 is started first to replenish the slurry from the circulating slurry pool 8. If the mud reserve in the circulating slurry pool 8 is insufficient, the new slurry pool 7 is switched to absorb the mud for replenishment. If the mud liquid level rises to more than the preset mud liquid level upper limit threshold, the grouting pump 6 is started to suck the mud above the stable height of the liquid level into the waste slurry pool 10. When the positive circulation grouting pump 1 and the reverse circulation grouting pump 2 have been running continuously for one hour, the positive circulation grouting pump 1, the reverse circulation grouting pump 2, and the grouting pump 5 or the grouting pump 6 started according to the change of the liquid level are turned off in turn;

[0073] S4: Replace the positive circulation grouting pump with the reverse circulation grouting pump, and execute S3 again.

[0074] Specifically, remove the connection between the positive circulation grouting pump 1 and the first conduit 3, and the connection between the reverse circulation grouting pump 2 and the second conduit 4. Then connect the grouting port of the positive circulation grouting pump 1 to the second conduit 4, and the grouting port of the reverse circulation grouting pump 2 to the first conduit 3. Start the positive circulation grouting pump 1 and the reverse circulation grouting pump 2 at the same time again, monitor the change of the slurry level in the ground connection wall groove 11, and start the grouting pump 5 to replenish grout or the grouting pump 6 to absorb slurry according to the rise and fall of the liquid level, just like the first slag cleaning. When the running time of the positive circulation grouting pump 1 and the reverse circulation grouting pump 2 reaches one hour, turn off the relevant pumps and complete the second position change slag cleaning; Figure 2 shown.

[0075] S5: Determine whether the sediment index of the ground-connected wall groove 11 meets the specification; if not, return to step S3; otherwise, enter step S6.

[0076] Specifically, a sediment detector is used to deeply detect the sediment situation in the ground-connected wall groove 11. If the detection result shows that the sediment index meets the specification, step S6 is entered; if it does not meet the specification, the slag cleaning time and the frequency of position change are optimized based on the sediment data, and steps S3 and S4 are repeated, and the forward and reverse cycle position change slag cleaning is performed again until the sediment is completely cleaned and the sediment detection in the groove is completed; the specific content of optimizing the slag cleaning time and the frequency of position change based on the sediment data is: when the sediment thickness in the ground-connected wall groove 11 is greater than the preset sediment thickness threshold or the sediment reduction rate in the ground-connected wall groove 11 is less than 50%, the single slag cleaning time is extended by 10%, and the number of position changes is increased by at least 3 times.

[0077] S6: Equipment removal and concrete pouring funnel.

[0078] Specifically, after the sediment is tested and found to be qualified, the positive circulation grouting pump 1, the reverse circulation grouting pump 2 and related connecting pipes and other equipment are removed, and the first conduit 3 or the second conduit 4 is installed with a concrete pouring funnel to complete the equipment removal work, such as Figure 3 shown.

[0079] In this embodiment, the head selection of the positive circulation grouting pump 1 in S1 should meet the following empirical formula requirements:

[0080] H ≥ k × (z + hw);

[0081] Among them, H is the design value of the pump head, z is the head height, that is, the sum of the elevation difference from the water surface at the inlet to the water surface at the outlet and 1 / 10 of the length of the pipeline from the inlet to the outlet, hw is the head loss, and k is the head experience coefficient, which is to ensure the safety margin of the head.

[0082] In this embodiment, the flow rate selection of the positive circulation grouting pump 1 in S1 should meet the following requirements: when the bottom of the local diaphragm trench is a hard rock layer: Q≥hab / 6, P=ηρvh>c, where When the bottom of the diaphragm wall is a soft soil layer: 2.0c<P=ηρvh>c, where If the bottom of the ground-connected wall trench is a sand layer: 1.5c<P=ηρvh>c, where Among them, Q is the flow rate, h is the height of the ground-connected wall, a is the thickness of the ground-connected wall, b is the width of the ground-connected wall, P is the dynamic water pressure of the grouting liquid to the edge of the groove, η is the flow rate empirical coefficient, ρ is the density of the grouting slurry, v is the flow velocity at the outlet, and c is the cohesion of the sediment, which is obtained by experiment.

[0083] In this embodiment, the head selection of the reverse circulation slurry suction pump 2 in S1 should meet the following empirical formula requirements:

[0084] H ≥ k × z

[0085] Among them, H is the design value of the pump head, z is the head height, that is, the elevation difference between the water surface at the inlet and the water surface at the outlet, that is, the length of the conduit 3 or the conduit 4.

[0086] In this embodiment, the flow rate selection of the positive circulation grouting pump 1 in S1 should meet the following requirements: when the bottom of the local diaphragm groove is a hard rock layer: Q≥hab / 6, P=ηρvh>c, where When the bottom of the local diaphragm trench is a soft soil layer: 2.0c<P=ηρvh>c, where When the bottom of the local ditch is a sand layer: 1.5c<P=ηρvh>c, where Wherein, Q is the flow rate, h is the height of the ground-connected wall, a is the thickness of the ground-connected wall, b is the width of the ground-connected wall, η is the empirical coefficient of flow rate, ρ is the density of grouting slurry, v is the flow velocity at the outlet, c is the cohesion of sediment obtained by experiment, and D is the inner diameter of the conduit.

[0087] In this embodiment, the first conduit 3 and the second conduit 4 in S2 should be conduits for concrete casting, and the inner diameter of the conduit should be not less than 250 and not less than 1 / 4 of the groove width. A watertightness test should be carried out before installation. The requirements that the watertightness test should meet are: assemble the conduit and weld the steel plates at both ends to seal; inject water, the water injection amount is greater than 70% of the total volume of the sealed conduit; pressurize, add air to the calculated pressure value P1 with an air compressor; the pressure value P1 is calculated by:

[0088] P1≥1.5gh and P1≥24h1-12h2;

[0089] Among them, P1 is the pressure value injected by the air compressor, h is the height of the ground-connected wall, h1 is the length of the conduit, h2 is the depth of the mud in the groove, and g is the acceleration of gravity.

[0090] In this embodiment, the grouting pump 5 and the grouting pump 6 in S3 can be equipped with a flow rate Q greater than 15m3 / h and a head H greater than 20m. They only serve to balance the liquid level in the tank 11, and the liquid level 11 in the ground-connected wall tank should be higher than the groundwater level by more than 0.5m.

[0091] It should be noted that in the embodiment of the present invention, when the positive circulation grouting pump 1, the reverse circulation grouting pump (2), the grouting pump 5 and the grouting pump 6 are operated synchronously, a complex vibration coupling effect will be generated due to the differences in their respective operating frequencies and pressure pulsations. These vibrations may be transmitted to the ground-connected wall groove 11 through the pipeline, disturbing the stability of the groove wall and even inducing local soil collapse. In addition, under long-term operation, fatigue stress at the connection between the pump and the pipeline may cause seal failure or shorten the life of the equipment.

[0092] Based on this, the slag cleaning operation of S3 specifically includes steps S31-S33.

[0093] Step S31, obtaining vibration data, and calculating standardized vibration intensity based on soil layer type.

[0094] Specifically, the vibration acceleration can be collected in real time using a slot wall vibration sensor, and the vibration intensity V can be calculated based on this, as shown in the following formula:

[0095]

[0096] Where a(t) is the vibration acceleration, t represents time, and T is the monitoring period, which is a constant and is usually set to 10s.

[0097] In an embodiment of the present invention, the normalized vibration intensity V n As shown below:

[0098]

[0099] Among them, V m is the vibration intensity threshold of the soil layer, which can be determined based on experiments. Usually, the ratio of the vibration intensity thresholds of the hard rock layer, soft soil layer and sand layer is approximately 55:28:38. For example, the vibration intensity threshold of the hard rock layer can be set to 0.7m / (s*s).

[0100] Step S32, calculating the vibration influence factor and the liquid level influence factor.

[0101] In an embodiment of the present invention, the vibration influence factor and the liquid level influence factor are shown in the following formula:

[0102]

[0103] f h =1+k h |Δh|

[0104] Among them, f v With f h are vibration influence factor and liquid level influence factor, respectively, k v is the vibration sensitivity coefficient, which is set according to the soil layer type. The vibration sensitivity coefficients of hard rock layer, soft soil layer and sand layer can be set to 0.2, 0.5 and 0.3 respectively. h is the liquid level change sensitivity coefficient, which is a constant and can be set to 0.1s / m. Δh is the liquid level change rate, which can be measured in real time based on the liquid level sensor.

[0105] Step S33, adjusting the head empirical coefficient and the flow empirical coefficient respectively based on the vibration influence factor and the liquid level influence factor.

[0106] The head experience coefficient k and flow rate experience coefficient η are shown as follows:

[0107] k=u1×(f v -1)+(1-u1)×(f h -1)

[0108] η=u2×(f v -1)+(1-u2)×(f h -1)

[0109] Wherein, u1 and u2 are empirical parameters respectively. In the embodiment of the present invention, the values ​​of u1 and u2 can be 0.8 and 0.65 respectively.

Claims

1. A synchronous slag removal device for forward and reverse circulation of ground-connected walls, characterized in that: It includes a new slurry pool, a circulating slurry pool, a slurry making pool and a waste slurry pool. The new slurry pool stores fresh slurry for injecting fresh slurry into the ground-connected wall groove; the circulating slurry pool is used for replenishing slurry; the slurry making pool is used for making fresh slurry and injecting it into the new slurry pool; the waste slurry pool is used for extracting waste slurry from the ground-connected wall groove; The new slurry pool is connected to the slurry suction port of the positive circulation grouting pump through a pipeline, and the positive circulation grouting pump is connected to the first conduit; fresh slurry is injected into the ground-connected wall groove; a grouting pump is provided at one end of the top of the ground-connected wall groove, and the grouting pump is connected to the circulating slurry pool through a pipeline; a slurry suction pump is provided at the other end of the top of the ground-connected wall groove, and the slurry suction pump is connected to the waste slurry pool through a pipeline; the waste slurry pool is connected to the slurry outlet of the reverse circulation suction slurry pump through a pipeline, and the reverse circulation suction slurry pump is connected to the second conduit to pump the waste slurry to the waste slurry pool.

2. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall, using the synchronous slag removal equipment for positive and negative circulation of ground-connected wall as claimed in claim 1, characterized in that: The following steps are involved: S1: Based on the parameter characteristics of the ground-connected wall, calculate the head and flow rate of the positive circulation grouting pump and the reverse circulation grouting pump; S2: Based on the head and flow of the positive circulation grouting pump and the reverse circulation grouting pump, match the model of the synchronous slag cleaning equipment and complete the equipment installation; S3: Based on the change of the slurry level in the ground-connected wall groove, the start and stop of the new slurry pool, the circulating slurry pool, the slurry pool and the waste slurry pool are controlled to complete the slag removal operation; S4: Replace the positive circulation grouting pump with the reverse circulation grouting pump, and execute S3 again; S5: Determine whether the sediment index of the ground-connected wall groove meets the specification; if not, return to step S3; otherwise, enter step S6; S6: Equipment removal and concrete pouring funnel.

3. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall as claimed in claim 2, characterized in that: The head selection of the positive circulation grouting pump in S1 meets the following requirements: H≥k×(z+hw) Among them, H is the design value of the pump head, z is the head height, that is, the sum of the elevation difference from the water surface at the inlet to the water surface at the outlet and 1 / 10 of the length of the pipeline from the inlet to the outlet, hw is the head loss, and k is the head experience coefficient.

4. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall as claimed in claim 2, characterized in that: The flow selection of the positive circulation grouting pump in S1 should meet the following requirements: When the bottom of the diaphragm wall is a hard rock layer: Q ≥ hab / 6, P = ηρvh > c, where When the bottom of the diaphragm wall is a soft soil layer: 2.0c<P=ηρvh>c, where If the bottom of the ground-connected wall trench is a sand layer: 1.5c<P=ηρvh>c, where Among them, Q is the flow rate, h is the height of the ground-connected wall, a is the thickness of the ground-connected wall, b is the width of the ground-connected wall, P is the dynamic water pressure of the grouting liquid to the edge of the groove, η is the flow rate empirical coefficient, ρ is the density of the grouting slurry, v is the flow velocity at the outlet, and c is the cohesion of the sediment, which is obtained by experiment.

5. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall as claimed in claim 2, characterized in that: The head selection of the reverse circulation slurry suction pump in S1 should meet the requirements of the following empirical formula: H ≥ k × z Among them, H is the design value of the pump head, z is the head height, that is, the elevation difference between the water surface at the inlet and the water surface at the outlet, that is, the length of the conduit.

6. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall as claimed in claim 2, characterized in that: The flow selection of the positive circulation grouting pump in S1 should meet the following requirements: When the bottom of the local diaphragm groove is a hard rock layer: Q ≥ hab / 6, P = ηρvh > c, where When the bottom of the local ditch is a soft soil layer: 2.0c<P=ηρvh>c, where When the bottom of the local ditch is a sand layer: 1.5c<P=ηρvh>c, where Among them, Q is the flow rate, h is the height of the ground-connected wall, a is the thickness of the ground-connected wall, b is the width of the ground-connected wall, η is the flow rate empirical coefficient, ρ is the density of the grouting slurry, v is the flow velocity at the outlet, and c is the cohesion of the sediment obtained by experiment.

7. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall as claimed in claim 2, characterized in that: The first conduit and the second conduit in S2 should be conduits for concrete pouring, with an inner diameter of not less than 250 and not less than 1 / 4 of the slot width. A watertightness test should be carried out before installation. The requirements of the watertightness test should be as follows: Assemble the conduit and seal both ends with steel plate welding; Inject water, the amount of water injected is greater than 70% of the total volume of the sealed conduit; Pressurize, add air with an air compressor to the calculated pressure value P1; the pressure value P1 is calculated as follows: P1≥1.5gh and P1≥24h1-12h2; Among them, P1 is the pressure value injected by the air compressor, h is the height of the ground-connected wall, h1 is the length of the conduit, and h2 is the depth of the mud in the trench.

8. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall as claimed in claim 2, characterized in that: The grouting pump and suction pump in S3 are equipped with a flow rate Q greater than 15m3 / h and a lift H greater than 20m, and the liquid level in the ground-connected wall groove should be more than 0.5m higher than the groundwater level.

9. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall as claimed in claim 2, characterized in that: The slag removal operation of S3 specifically includes steps S31-S33; Step S31, obtaining vibration data and calculating standardized vibration intensity based on soil layer type; Step S32, calculating the vibration influence factor and the liquid level influence factor; Step S33, adjusting the head empirical coefficient and the flow empirical coefficient respectively based on the vibration influence factor and the liquid level influence factor.

10. A synchronous slag removal construction method for positive and negative circulation of ground-connected wall as claimed in claim 9, characterized in that: The vibration intensity V is as follows: Where a(t) is the vibration acceleration, t represents time, and T is the monitoring period; Standardized vibration intensity V n As shown below: Among them, V m is the vibration intensity threshold of the soil layer; The vibration influence factor and liquid level influence factor are shown in the following formula: f h =1+k h |Δh| Among them, f v With f h are vibration influence factor and liquid level influence factor, respectively, k v is the vibration sensitivity coefficient, k h is the liquid level change sensitivity coefficient, Δh is the liquid level change rate; The head experience coefficient k and flow rate experience coefficient η are shown as follows: k=u1×(f v -1)+(1-u1)×(f h -1) η=u2×(f v -1)+(1-u2)×(f h -1) Among them, u1 and u2 are empirical parameters.

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