Treatment and inspection cooperative grouting treatment method for unconsolidated formation

Abstract

The invention belongs to the field of coal mine water prevention and control, and particularly relates to a loose bed treatment and inspection cooperative grouting treatment method which comprises the steps that S1, treatment area hole site determination is conducted, specifically, a plurality of drill holes are formed in a treatment area at equal intervals, the drill holes are arranged in a quincunx shape, and the distance d between the drill holes is 25-60 m; s2, drilling and well completion are conducted, specifically, a drilled hole is of a second-opening structure, and first-opening drilling is conducted to the top of the treatment section of the unconsolidated formation; s3, hole sweeping and downward extending drilling are carried out, wherein each drill hole is divided into a plurality of treatment subsections; holes are swept in rows according to the design construction sequence, and a treatment segment length l is drilled in a downward extending mode; s4, grouting-inspection cooperative construction is carried out, specifically, grouting propulsion is carried out in batches and in sequence, a drilled hole adjacent to a grouting hole is an inspection hole, multiple purposes of one hole are achieved, and a treatment hole is the inspection hole; s5, repeating the steps S3 and S4 in the same way until grouting of the treatment section is completely completed; according to the method, by optimizing the grouting treatment sequence, treatment and inspection cooperation in the advancing process of the unconsolidated formation reconstruction project is achieved, timely and dynamic improvement of the grouting scheme is promoted, and the optimal treatment effect is achieved.

Description

Technical Field

[0001] The invention belongs to the technical field of coal mine water prevention and control, and specifically relates to a loose layer treatment and inspection coordinated grouting treatment method. Background Art

[0002] The loose layer of the coal seam roof is generally composed of clay, sand, gravel and other components, which are rich in water. Improper treatment can easily cause water and sand burst accidents, threatening the safety of underground mining. In the implementation of the previous loose layer ground grouting project, the grouting control methods mainly include quantitative grouting and constant pressure grouting. The grouting volume and stop pressure are determined by empirical values ​​or empirical formulas. The relevant experience has a certain applicability in the same area, but in different regions and when the geological conditions are quite different, the empirical formula (value) needs to be adjusted according to the actual project, which makes it difficult to promote this grouting treatment method on a large scale. On the other hand, the existing grouting methods are mainly based on large-area multi-hole and group hole grouting. The grouting effect is mainly based on post-construction inspection. The effect cannot be tested in time during the construction process, and it is impossible to achieve coordinated construction of treatment and inspection. In short, the traditional grouting control empirical method has poor applicability under different geological conditions and the grouting effect is difficult to test in time.

[0003] Therefore, it is necessary to provide an improved technical solution to address the above-mentioned deficiencies in the prior art. Summary of the invention

[0004] The purpose of the present invention is to overcome the shortcomings of the prior art and provide a loose layer treatment and inspection coordinated grouting treatment method, which adopts a one-hole-for-multiple-purposes approach to achieve parallel advancement of grouting treatment and effect inspection. During the treatment process, there is no need to distinguish between treatment holes and inspection holes, and "grouting" is used instead of "inspection" to achieve coordinated treatment and inspection.

[0005] In order to achieve the above object, the present invention provides the following technical solutions:

[0006] A loose layer treatment and inspection coordinated grouting treatment method, comprising the following steps:

[0007] S1. Determination of borehole positions in the treatment area: several boreholes are opened at equal intervals in the treatment area, and the boreholes are arranged in a plum blossom shape, with a borehole spacing d of 25m to 60m; the boreholes are divided into the first row, the second row, the third row, the fourth row...the Nth row according to the grouting advancement sequence;

[0008] S2. Drilling and well completion: The borehole is a two-opening structure. The first opening is drilled to the top of the loose layer treatment section; the casing is lowered to the bottom of the first opening in the borehole, and cement slurry is injected. Wait for 24 to 48 hours until the casing is completely fixed; repeat the above steps in sequence until all boreholes are drilled and wells are completed;

[0009] S3, hole sweeping and downward drilling: Each borehole is divided into several treatment sections; the holes are swept according to the design construction sequence, and the holes are swept and downward drilled for a treatment section length l; the sum of all treatment section lengths l of each borehole is recorded as the treatment section length L;

[0010] S4, grouting-inspection coordinated construction: Use cement or cement and fly ash mixed slurry with a specific gravity of 1.3-1.8 for grouting, and grout the first section of treatment in sections. First, use odd-numbered holes as grouting holes and even-numbered holes as inspection holes. Calculate the time T required for the slurry to diffuse from the grouting holes to the inspection holes. If all the inspection holes are penetrated within T time, the grouting of this batch is completed, otherwise the holes without grouting are marked; then use even-numbered holes as grouting holes and odd-numbered holes as inspection holes. If all the inspection holes are penetrated within T time, the grouting of this treatment section is completed, otherwise the holes without grouting are marked; refill the holes without grouting;

[0011] S5. Repeat S3 and S4 in the same way until the grouting of the treatment section is completed; count the number of times grouting occurs in all holes and calculate the grouting rate s.

[0012] Furthermore, in S1, the borehole spacing d is adjusted according to the water-richness of the loose layer. The borehole spacing d in the weakly water-rich area is 40≤d<60 meters, the borehole spacing d in the moderately water-rich area is 30≤d<40, the borehole spacing d in the strong water-rich area is 25≤d<30, and the borehole spacing d in the extremely strong water-rich area is 20≤d<25.

[0013] Furthermore, in S3, the first and second rows are firstly drilled and extended by a treatment segment length l, and after the subsequent grouting starts, every two rows are drilled simultaneously and extended by a treatment segment length l starting from the third row.

[0014] Furthermore, in S2, the inner diameter φ of the casing can be 139.7 mm or 177.8 mm.

[0015] Furthermore, in S3, different treatment segment lengths l are selected according to the lithology, the treatment segment length l in the clay area is 6m to 10m, the treatment segment length l in the sand area is 4m to 6m, and the treatment segment length l in the gravel area is 3m to 4m.

[0016] Furthermore, the time T required for the slurry to diffuse from the grouting hole to the inspection hole is:

[0017]

[0018] Where: d is the drilling distance, unit: m; l is the treatment section length, unit: m; e is the treatment section porosity; Q is the orifice grouting flow, unit: m 3 / h.

[0019] Furthermore, the cement model in S4 is PO32.5 or PO42.5, and the fly ash is of secondary fly ash or above; in the cement and fly ash mixed slurry, the mass ratio of cement to fly ash is 5:1 to 2:1.

[0020] Furthermore, in S4, when the lithology of the treatment section is dense clay, the orifice grouting flow rate Q is 3.12m 3 / h; When the lithology of the treatment section is mainly clay, the orifice grouting flow rate Q is 5.4m 3 / h; When the lithology of the treatment section is mainly sand, the orifice grouting flow rate Q is 9.6m 3 / h; When the lithology of the treatment section is mainly gravel, the orifice grouting flow rate Q is 15m 3 / h; When the rock properties of the treated section are all gravel, the orifice grouting flow rate Q is 23.4m 3 / h.

[0021] Furthermore, in S5, the calculation formula of the pulp penetration rate s is as follows:

[0022]

[0023] Among them, n c is the number of boreholes where slurry seepage occurs, and N is the total number of all boreholes.

[0024] Furthermore, in S5, the grouting pressure at the orifice of the borehole without grouting is required to reach the stop grouting pressure P t It can be stabilized for 1 hour, and the injection hole pressure P t Take 1.5 times the hydrostatic pressure before drilling and grouting.

[0025] The beneficial effects of the present invention are:

[0026] The present invention solves the problems of poor universality and delayed effect inspection of traditional methods in the process of grouting in loose layers. The present invention optimizes the spatial arrangement of treatment boreholes, adopts a one-hole multi-purpose heating method, and no longer distinguishes between treatment holes and inspection holes during the grouting process. The treatment holes are inspection holes, thereby realizing the parallel advancement of grouting treatment and effect inspection during the project advancement and realizing the coordination of treatment and inspection; and supplementary injection is carried out according to the inspection results to improve the grouting treatment effect of the loose layer. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] The drawings constituting a part of the present application are used to provide a further understanding of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. Among them:

[0028] Figure 1 Schematic diagram of drilling layout according to an embodiment of the present invention.

[0029] Figure 2The process diagram of the first treatment segment grouting in the embodiment of the present invention is shown in FIG. Figure 1 .

[0030] Figure 3 The process diagram of the first treatment segment grouting in the embodiment of the present invention is shown in FIG. Figure 2 .

[0031] Figure 4 This is a schematic diagram of the process of segmented grouting in the second treatment embodiment of the present invention.

[0032] Figure 5 This is a schematic diagram of the process of grouting in the first treatment section of the first row of holes in an embodiment of the present invention.

[0033] Figure 6 This is a schematic diagram of the process of grouting in the first treatment section of the third row of holes in an embodiment of the present invention.

[0034] Figure 7 It is a schematic diagram of the drilling double opening structure of an embodiment of the present invention.

[0035] Figure 8 This is a comparison diagram of the core before and after grouting of an embodiment of the present invention. DETAILED DESCRIPTION

[0036] The technical solutions in the embodiments of the present invention are described clearly and completely below. Obviously, the described embodiments are only part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field belong to the scope of protection of the present invention.

[0037] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0038] A loose layer treatment and inspection coordinated grouting treatment method, comprising the following steps:

[0039] S1. Determination of borehole positions in the treatment area: several boreholes are opened at equal intervals in the treatment area, and the boreholes are arranged in a plum blossom shape. The borehole spacing d is 25m to 60m, and the borehole spacing d is adjusted according to the water-richness of the loose layer; the boreholes are divided into the first row, the second row, the third row, the fourth row...the Nth row according to the grouting advancement sequence;

[0040] S2. Drilling and well completion: The borehole is a two-opening structure. The first opening is drilled to the top of the loose layer treatment section. The steel casing is lowered to the bottom of the first opening. The drill pipe is used to inject grout from the bottom until the slurry returns to the ground from the annulus outside the casing. Wait for 24 to 48 hours until the casing is completely fixed. Repeat the above steps in sequence until all the boreholes are drilled and wells are completed.

[0041] S3, hole sweeping and downward drilling: Each borehole is divided into several treatment sections; according to the design and construction sequence, the holes are swept and the length of a treatment section l is drilled downward; the sum of the lengths l of all treatment sections of each borehole is the total length L of the treatment section; Figure 2 , Figure 3 As shown, the borehole is being grouted in the first treatment section. The total length of the treatment section L is shown in the loose layer grouting treatment section area. The total length of the treatment section L is the length from the bottom of the opening to the bedrock surface. Figure 7 The treatment section is schematically divided into four treatment sections (not limited to this in actual working conditions), and the treatment section length l and the total treatment section length L are marked;

[0042] S4, grouting-inspection coordinated construction: Use cement or cement and fly ash mixed slurry with a specific gravity of 1.3-1.8 for grouting, and grout the first section of treatment in sections. First, use odd-numbered holes as grouting holes and even-numbered holes as inspection holes. Calculate the time T required for the slurry to diffuse from the grouting holes to the inspection holes. If all the inspection holes are penetrated within T time, the grouting of this batch is completed, otherwise the holes without grouting are marked; then use even-numbered holes as grouting holes and odd-numbered holes as inspection holes. If all the inspection holes are penetrated within T time, the grouting of this treatment section is completed, otherwise the holes without grouting are marked; refill the holes without grouting;

[0043] S5. Repeat S3 and S4 in the same way until the grouting of the treatment section is completed; count the number of times grouting occurs in all holes and calculate the grouting rate s.

[0044] Furthermore, when arranging the drilling holes in S1, the treatment area is first divided into equilateral triangles so that the distances between adjacent nodes are equal after the division, and the node positions are the drilling hole positions.

[0045] Furthermore, in S1, the drilling spacing d is selected according to the following table:

[0046] Table 1 Drilling spacing selection table

[0047]

[0048] Furthermore, in S3, the first and second rows are firstly drilled and extended to a treatment segment length l, and after the subsequent grouting starts, every two rows are simultaneously drilled and extended to a treatment segment length l starting from the third row; only one row of holes is drilled each time.

[0049] Taking the first treatment section of the first six rows of boreholes as an example, the first and second rows are firstly swept and drilled down to a treatment section length l; in this batch, the odd-numbered holes are used as grouting holes, and the even-numbered holes are used as inspection holes. While the first row of boreholes is grouting the first treatment section and the second row of boreholes is used as inspection holes, the third and fourth rows are swept and drilled down to the bottom of the first treatment section; Figure 5As shown, the first and second rows of boreholes are about to be grouted and inspected, and the third and fourth rows of boreholes are being drilled to the bottom of the first treatment branch end;

[0050] After that, the third row of holes is grouted, the fourth row of holes is used as inspection holes, and the fifth and sixth rows of holes are swept and extended to the bottom of the first treatment section. Figure 6 As shown, the first and second rows of boreholes have been grouted, the third and fourth rows of rotation holes are about to be grouted and inspected, and the fifth and sixth rows of boreholes have been drilled to the bottom of the first treatment section; and so on until all the boreholes have been drilled to the bottom of the first treatment section; Figure 2 It is assumed that there are eight rows of boreholes in total (the actual number of boreholes in construction is much greater than this), and all the boreholes have been drilled to the bottom of the first treatment section. Figure 2 The figure shows the working process of odd-numbered holes as grouting holes and even-numbered holes as inspection holes.

[0051] After that, the even-numbered holes are used as grouting holes, and the odd-numbered holes are used as inspection holes, until the first treatment section of all the boreholes is treated; Figure 3 Schematic diagram of the working process of making even-numbered holes as grouting holes and odd-numbered holes as inspection holes; Figure 4 This is a schematic diagram of the first treatment section treatment of all boreholes. The black dot filled area in the figure is the grouting area;

[0052] Then the next round begins, i.e. the treatment of the second treatment section of the borehole. During the final drilling and grouting of the treatment of the first section of the borehole, the first and second rows of boreholes and the second treatment section are swept and drilled downwards at the same time; then the first and second rows of boreholes and the second treatment section are grouted and inspected, and the third and fourth rows of boreholes and the second treatment section are swept and drilled downwards at the same time, and so on, until the grouting of all treatment sections is completed.

[0053] Furthermore, in S2, the inner diameter φ of the casing can be 139.7 mm or 177.8 mm.

[0054] Furthermore, in S3, different treatment segment lengths l are selected according to the lithology, and the treatment segment length l is selected according to the following table:

[0055] Table 2 Governance section length selection table

[0056] Lithology clay sand gravel Governance section length l / (m) 6～10 4～6 3～4

[0057] Furthermore, the time T required for the slurry to diffuse from the grouting hole to the inspection hole is:

[0058]

[0059] Where: d is the drilling distance, unit: m; l is the treatment section length, unit: m; e is the treatment section porosity; Q is the orifice grouting flow, unit: m 3 / h.

[0060] Furthermore, the cement model in S4 is PO32.5 or PO42.5, and the fly ash is of secondary fly ash or above; in the cement and fly ash mixed slurry, the mass ratio of cement to fly ash is 5:1 to 2:1.

[0061] Furthermore, in S4, when the lithology of the treatment section is dense clay, the orifice grouting flow rate Q is 3.12m 3 / h; When the lithology of the treatment section is mainly clay, the orifice grouting flow rate Q is 5.4m 3 / h; When the lithology of the treatment section is mainly sand, the orifice grouting flow rate Q is 9.6m 3 / h; When the lithology of the treatment section is mainly gravel, the orifice grouting flow rate Q is 15m 3 / h; When the rock properties of the treated section are all gravel, the orifice grouting flow rate Q is 23.4m 3 / h.

[0062] Furthermore, the slurry penetration rate s in S5 can reflect the grouting construction effect. The higher the slurry penetration rate s, the denser the cement slurry veins formed by the slurry in the loose layer, and the better the treatment effect. The calculation formula of the slurry penetration rate s is as follows:

[0063]

[0064] Among them, n c is the number of boreholes where slurry seepage occurs, and N is the total number of all boreholes.

[0065] Furthermore, in S5, the grouting pressure at the orifice of the borehole without grouting is required to reach the stop grouting pressure P t It can be stabilized for 1 hour, and the injection hole pressure P t Take 1.5 times the hydrostatic pressure before drilling and grouting.

[0066] Next, we will take a certain weak water-rich loose layer management area as an example to explain in detail.

[0067] A loose layer treatment and inspection coordinated grouting treatment method, comprising the following steps:

[0068] S1. Grid division and hole position determination in the treatment area: The treatment area is divided into equilateral triangle grids so that the distances between adjacent nodes are equal after division. The node position is the drilling position. The loose layer in the treatment area is weakly water-rich. According to Table 1, the drilling spacing is 45m;

[0069] S2. Drilling and well completion: The borehole is a two-opening structure. The first opening is drilled to the top of the loose layer treatment section. The second opening is 245m deep. A φ177.8mm steel casing is lowered to the bottom of the first opening. The drill pipe is used to inject PO42.5 pure cement slurry from the bottom until the cement returns to the ground from the outer annulus of the casing. Wait for 24 hours until the casing is completely fixed. Repeat the above steps in sequence until all boreholes are drilled and wells are completed;

[0070] S3, hole sweeping and downward drilling: Figures 1 to 6 As shown, the hole sweeping construction is carried out from right to left. First, the two rows of boreholes on the right are swept and extended by a treatment segment length l. The lithology of the treatment segment is sand. According to Table 2, the treatment segment length l is 5m. After the subsequent grouting starts, every two rows are swept at the same time from the third row and extended by a treatment segment length.

[0071] S4, grouting-inspection coordinated construction: Use PO32.5 cement with a specific gravity of 1.5-1.8 for grouting; from right to left, use odd-numbered rows of holes as grouting holes, and even-numbered rows of holes as inspection holes; calculate the time T required for the slurry to diffuse from the grouting holes to the inspection holes according to formula (1); if all the inspection holes are grouted within T time, the current batch of grouting is completed; otherwise, mark the holes that are not grouted; complete the next batch of grouting from right to left in sequence, from right to left, use even-numbered rows of holes as grouting holes, and odd-numbered rows of holes as inspection holes, repeat the above steps until all holes have completed the first stage of grouting, and refill the holes that have not been grouted; "completion of the first stage of grouting" means that the first treatment section of all holes has completed grouting;

[0072] S5, repeating steps S3 and S4 until the grouting of the loose layer treatment section is completed, counting the number of times grouting occurs in all holes, calculating the grouting rate, and refilling the holes without grouting;

[0073] In this embodiment, the total number of grouting times is 392, and the grouting is 342 times. According to formula (2), the grouting rate is 86%. The grouting pressure at the orifice of the hole without grouting requires to reach the stop grouting hole pressure P t Stable for 1 hour, P t Take 1.5 times the hydrostatic pressure before grouting. For example, the hydrostatic pressure before grouting in a borehole is 2.1 MPa. The stop grouting hole pressure P is calculated. t 3.15MPa; the drilling and coring conditions in the treatment area before and after grouting treatment are as follows Figure 8 a is before grouting, Figure 8 b: After grouting, the cement slurry forms cement slurry veins in the loose layer, and the loose layer is effectively consolidated.

[0074] Specifically, in S4, it is known that the borehole spacing d = 45m, the treatment section length l = 5m, the treatment section porosity e = 0.22, and the orifice grouting flow rate Q is 15m 3 / h, according to formula (1), T = 38.9h;

[0075] Then the first row on the far right is grouting, and the second row is used as inspection holes. If all inspection holes have grouting within T = 38.9h, the grouting effect of this batch is achieved and the grouting is stopped (that is, if the inspection holes have grouting within T = 38.9h, the grouting can also be stopped in advance); otherwise, the grouting is stopped after 38.9h, and the inspection holes without grouting are marked; the first section of grouting of the odd-numbered rows is completed from right to left;

[0076] Then the second row on the far right is grouted and the third row is made into inspection holes. If all inspection holes are grouted within T=38.9h, the effect of this batch of grouting is achieved and the grouting is stopped; otherwise, the grouting is stopped after 38.9h and the inspection holes without grouting are marked; the first section of grouting in the even-numbered rows is completed from right to left.

[0077] The present invention optimizes the grouting treatment sequence, thereby achieving coordination of treatment and inspection during the advancement of the loose layer transformation project, promoting timely and dynamic improvement of the grouting plan, and achieving optimal treatment effect.

[0078] The preferred embodiments of the present invention are described in detail above in conjunction with the accompanying drawings. However, the present invention is not limited to the specific details in the above embodiments. Within the technical concept of the present invention, a variety of simple modifications can be made to the technical solution of the present invention, and these simple modifications all belong to the protection scope of the present invention.

[0079] It should also be noted that the various specific technical features described in the above specific embodiments can be combined in any suitable manner without contradiction. In order to avoid unnecessary repetition, the present invention will not further describe various possible combinations.

[0080] In addition, various embodiments of the present invention may be arbitrarily combined, and as long as they do not violate the concept of the present invention, they should also be regarded as the contents disclosed by the present invention.

Claims

1. A loose layer treatment and inspection coordinated grouting treatment method, characterized in that: The following steps are involved: S1. Determination of borehole positions in the treatment area: several boreholes are opened at equal intervals in the treatment area, and the boreholes are arranged in a plum blossom shape. The borehole spacing d is 25m to 60m, and the borehole spacing d is adjusted according to the water-richness of the loose layer; the boreholes are divided into the first row, the second row, the third row, the fourth row...the Nth row according to the grouting advancement sequence; S2. Drilling and well completion: The borehole is a two-opening structure. The first opening is drilled to the top of the loose layer treatment section; the casing is lowered to the bottom of the first opening in the borehole, and cement slurry is injected. Wait for 24 to 48 hours until the casing is completely fixed; repeat the above steps in sequence until all boreholes are drilled and wells are completed; S3. Borehole sweeping and downward drilling: Each borehole is divided into several treatment sections. The boreholes are swept according to the design construction sequence, and the boreholes are swept and downward drilled for a treatment section length l. The treatment section length l is 3m to 10m, and different treatment section lengths l are selected according to the lithology. S4, grouting-inspection coordinated construction: Use cement or cement and fly ash mixed slurry with a specific gravity of 1.3-1.8 for grouting, and grout the first section of treatment in sections. First, use odd-numbered holes as grouting holes and even-numbered holes as inspection holes. Calculate the time T required for the slurry to diffuse from the grouting holes to the inspection holes. If all the inspection holes are penetrated within T time, the grouting of this batch is completed, otherwise the holes without grouting are marked; then use even-numbered holes as grouting holes and odd-numbered holes as inspection holes. If all the inspection holes are penetrated within T time, the grouting of this treatment section is completed, otherwise the holes without grouting are marked; refill the holes without grouting; S5. Repeat S3 and S4 in the same way until the grouting of the treatment section is completed; count the number of grouting occurrences in all holes and calculate the grouting rate s.

2. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized by: In S1, the borehole spacing d in the weak water-rich area is 40≤d<60 meters, the borehole spacing d in the moderate water-rich area is 30≤d<40, the borehole spacing d in the strong water-rich area is 25≤d<30, and the borehole spacing d in the extremely strong water-rich area is 20≤d<25.

3. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized by: In S3, the first and second rows are firstly drilled and extended by a treatment segment length l. After the subsequent grouting starts, every two rows are drilled simultaneously and extended by a treatment segment length l starting from the third row.

4. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized in that: In S2, the inner diameter φ of the casing can be 139.7 mm or 177.8 mm.

5. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized by: In S3, the length of the clay area management segment l is 6m~10m, the length of the sand area management segment l is 4m~6m, and the length of the gravel area management segment l is 3m~4m.

6. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized by: The time T required for the slurry to diffuse from the grouting hole to the inspection hole is: Where: d is the drilling distance, unit: m; l is the treatment section length, unit: m; e is the treatment section porosity; Q is the orifice grouting flow, unit: m 3 / h.

7. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized by: The cement model in S4 is PO32.5 or PO42.5, and the fly ash is of grade II or above specification; in the cement and fly ash mixed slurry, the mass ratio of cement to fly ash is 5:1 to 2:

1.

8. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized by: In S4, when the lithology of the treatment section is dense clay, the orifice grouting flow rate Q is 3.12m 3 / h; When the lithology of the treatment section is mainly clay, the orifice grouting flow rate Q is 5.4m 3 / h; When the lithology of the treatment section is mainly sand, the orifice grouting flow rate Q is 9.6m 3 / h; When the lithology of the treatment section is mainly gravel, the orifice grouting flow rate Q is 15m 3 / h; When the rock properties of the treated section are all gravel, the orifice grouting flow rate Q is 23.4m 3 / h.

9. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized by: In S5, the calculation formula of the pulp penetration rate s is as follows: Among them, n c is the number of boreholes where slurry seepage occurs, and N is the total number of all boreholes.

10. The loose layer treatment and inspection coordinated grouting treatment method according to claim 1 is characterized in that: In S5, the grouting pressure at the orifice of the borehole without grouting requires the grouting pressure to reach the stop grouting pressure P t It can be stabilized for 1 hour, and the injection hole pressure P t Take 1.5 times the hydrostatic pressure before drilling and grouting.

Images