Trenchless pipe-jacking construction anti-drag slurry and preparation method thereof

Abstract

The invention relates to the technical field of pipe-jacking anti-drag slurry, and discloses non-excavation pipe-jacking construction anti-drag slurry and a preparation method thereof.The non-excavation pipe-jacking construction anti-drag slurry is characterized by being prepared from 85%-95% of water, 6%-10% of bentonite, 0.05%-0.15% of guar gum, 0.1%-0.25% of PAM and 0.1%-0.25% of borax. According to the non-excavation pipe-jacking construction resistance-reducing slurry and the preparation method thereof, bentonite, guar gum, PAM and borax are sequentially blended into water according to a certain proportion, the pH value and the temperature are adjusted, the additive PAM can interact with bentonite, a compact net-shaped structure is formed, the performance of the slurry is improved, and the resistance-reducing effect of the non-excavation pipe-jacking construction resistance-reducing slurry is achieved. Therefore, the pipe-jacking anti-drag slurry which is excellent in anti-drag effect, stable in structure, moderate in viscosity and optimal in various indexes and meets the pipe-jacking construction requirements is prepared.

Description

Technical Field

[0001] The invention relates to the technical field of pipe jacking drag reducing mud, in particular to a trenchless pipe jacking construction drag reducing mud and a preparation method thereof. Background Art

[0002] Although my country's pipe jacking construction technology started late, it has developed rapidly and has overtaken other countries, especially in the fields of new pipe jacking equipment and ultra-large-scale construction machinery research and development. At the same time, the pipe jacking machine industry is also constantly expanding the scale of infrastructure, and market demand continues to rise. With the acceleration of urbanization, the application areas of pipe jacking technology in China are constantly expanding, especially in large-diameter, long-distance, and difficult underground projects, showing unique advantages.

[0003] The mud technology used in pipe jacking construction is a key technology, which plays an important role in pipe jacking construction. Mud is not only used to balance soil pressure and groundwater pressure and maintain the stability of the working surface, but also used to carry gravel and soil slag out, and lubricate the cutter of the crushing bin, so as to ensure the smooth progress of construction. During underground pipe jacking construction, different geology conditions require different mud ratios or different types of mud to adapt to different projects. The present invention proposes a non-excavation pipe jacking construction drag reduction mud and preparation method. Through the implementation of scientific proportions, improved performance, enhanced recycling, strict treatment and strengthened supervision, these problems can be effectively solved, providing a strong guarantee for the sustainable development of pipe jacking projects. Summary of the invention

[0004] 1. Technical issues to be solved

[0005] In view of the shortcomings of the prior art, the present invention provides a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof, which has the advantages of excellent drag-reducing effect, acceptable impermeability, stable structure, moderate viscosity, and optimal indicators.

[0006] (II) Technical solution

[0007] The object of the present invention is to solve at least one of the technical drawbacks.

[0008] To this end, one purpose of the present invention is to propose a non-excavation pipe jacking construction drag reducing mud and a preparation method thereof to solve the problems mentioned in the background technology and overcome the shortcomings of the prior art.

[0009] To achieve the above object, an embodiment of the present invention provides a drag reduction slurry for trenchless pipe jacking construction, characterized in that the slurry components include 85-95% water, 6-10% bentonite, 0.05-0.15% guar gum, 0.1-0.25% PAM, and 0.1-0.25% borax.

[0010] Preferably, any of the above schemes comprises 89.65% water, 10% bentonite, 0.1% guar gum, 0.15% PAM and 0.1% borax; the bentonite component comprises 70% montmorillonite, 20% illite, 5% kaolinite, and a small amount of halloysite, zeolite, quartz and feldspar.

[0011] Preferably, the slurry components include 91.55% water, 8% bentonite, 0.15% guar gum, 0.15% PAM and 0.15% borax.

[0012] Preferably, the slurry components include 93.7% water, 6% bentonite, 0.1% guar gum, 0.1% PAM and 0.1% borax.

[0013] In order to achieve the above object, an embodiment of another aspect of the present invention provides a drag reducing slurry for trenchless pipe jacking construction and a preparation method thereof, comprising the following steps:

[0014] 1) First, add pure water into the container and heat it to a certain extent;

[0015] 2) Add bentonite, stirring while adding, and stirring evenly to make a solution;

[0016] 3) adding soda ash or caustic soda to the solution to adjust the pH value of the solution to 8-10;

[0017] 4) adding guar gum and PAM in sequence and stirring evenly to obtain diversified and excellent polymers;

[0018] 5) Finally, add borax and stir evenly. Borax and guar gum undergo cross-linking reaction to form an elastic gel.

[0019] Preferably, in step 2), the bentonite needs to be ground into powder, sieved and weighed, and then slowly added into the container after weighing.

[0020] Preferably, in step 3), soda ash and caustic soda are weighed, one of which is selected and gradually added to the solution, wherein stirring is performed continuously, and the pH value is measured using a test paper.

[0021] (III) Beneficial effects

[0022] Compared with the prior art, the present invention provides a drag reduction slurry for trenchless pipe jacking construction and a preparation method thereof, which has the following advantages:

[0023] Beneficial effects:

[0024] The drag-reducing mud for trenchless pipe jacking construction and the preparation method thereof are prepared by sequentially mixing a certain proportion of bentonite, guar gum, PAM and borax into influent water, and adjusting the pH value and temperature of the water. The admixture PAM can interact with the bentonite to form a dense network structure, thereby improving the performance of the mud. Thus, the pipe jacking drag-reducing mud with excellent drag-reducing effect, standard impermeability, stable structure, moderate viscosity and optimal indicators is obtained, thereby meeting the needs of pipe jacking construction. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 A broken line diagram showing the influence of the material content on the funnel viscosity of a drag-reducing slurry for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0026] Figure 2 A broken line diagram showing the influence of material content on water loss in a drag-reducing slurry for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0027] Figure 3 A broken line diagram showing the influence of material content on water separation rate of a drag reduction slurry for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0028] Figure 4 A broken line diagram showing the influence of material content on dynamic shear force of a drag-reducing slurry for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0029] Figure 5 A schematic diagram of the relationship between the mud performance and the bentonite content of a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0030] Figure 6 A schematic diagram of the relationship between the mud properties and the guar gum content of a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0031] Figure 7 A schematic diagram of the relationship between the mud performance and the PAM content of a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0032] Figure 8 A schematic diagram of the relationship between the mud performance parameters and the borax dosage of a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0033] Fig. 9 A broken line diagram of the influence of bentonite on the performance of a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0034] Fig.10 A broken line diagram of the effect of guar gum on the performance of a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0035] Fig.11 A broken line diagram of the effect of polyacrylamide on the performance of a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof proposed by the present invention;

[0036] Fig.12 This is a broken line diagram of the effect of a single amount of borax on the performance of a drag-reducing mud for trenchless pipe jacking construction and a preparation method thereof proposed in the present invention. DETAILED DESCRIPTION

[0037] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0038] Embodiment 1:

[0039] A drag reduction mud for trenchless pipe jacking construction, comprising 89.65% water, 10% bentonite, 0.1% guar gum, 0.15% PAM, and 0.1% borax, wherein the bentonite component comprises 70% montmorillonite, 20% illite, 5% kaolinite, and a small amount of halloysite, zeolite, quartz, and feldspar. Bentonite, guar gum, PAM, and borax are sequentially mixed at this ratio to prepare the mud, which has excellent drag reduction effect, meets the standard of impermeability, has stable structure, moderate viscosity, and achieves the best in various indicators, and is the preferred ratio for pipe jacking construction mud.

[0040] Embodiment 2:

[0041] A drag-reducing mud for trenchless pipe jacking construction, comprising 91.55% of water, 8% of bentonite, 0.15% of guar gum, 0.15% of PAM and 0.15% of borax. Compared with the first embodiment, the funnel viscosity of the embodiment is higher, the fluidity index is lower, the drag-reducing effect is reduced, and the structural stability is reduced.

[0042] Embodiment three:

[0043] The invention discloses drag-reducing mud for trenchless pipe jacking construction, which comprises 93.7% of water, 6% of bentonite, 0.1% of guar gum, 0.1% of PAM and 0.1% of borax.

[0044] 1. According to Example 1, Example 2 and Example 3, an orthogonal test was set up, and the orthogonal table is shown in Table 1. At the same time, the contents of bentonite, guar gum, PAM and borax were used as influencing factors, and each factor was set to five proportions, with a total of 25 groups of tests set up. The test was used to determine mud indicators such as water loss, funnel viscosity, water separation rate, dynamic shear force, etc. The test structure is shown in Table 2.

[0045] Table 1 Ratio parameter values

[0046]

[0047] Among them, A-sodium bentonite, B-guar gum, C-polyacrylamide, and D-borax.

[0048] The performance parameters of thixotropic mud were measured by orthogonal design test. The steps are as follows: first, sodium bentonite, guar gum, polyacrylamide and borax were mixed according to the orthogonal design ratio, and stirred for ten minutes using KC-3S mud mixer, and then the various properties of thixotropic muds of various ratios were measured using ZNN-D6B six-speed rotary viscometer, and then the funnel viscosity was measured using Marsh funnel, and the water loss was measured using API pump filter loss meter, and then the mud was injected into a stoppered measuring cylinder to calculate the water separation rate.

[0049] According to the orthogonal test results, the range analysis of the slurry properties was carried out. For the four factors, the average value of each factor at a certain level was calculated to obtain five levels, and then the range of the factor at the five levels was calculated, that is, the difference between the maximum and minimum values ​​in the five levels. The larger the range, the greater the impact of the factor on the indicator.

[0050] Table 2 Orthogonal test design table and test results

[0051]

[0052] Table 3 Orthogonal test range analysis

[0053]

[0054] 1. Funnel viscosity range analysis (RA = 52.15, RB = 7.65, RC = 20.10, RD = 23.54):

[0055] According to the range analysis results in Table 3 and Figure 1It can be seen that bentonite has the largest range among the five levels, indicating that the change in bentonite content has the most significant effect on the funnel viscosity of the mud. The funnel viscosity is the largest when the bentonite content is 12%. The increase in guar gum and PAM content has a relatively low effect on the funnel viscosity of the mud. As the borax content increases, the funnel viscosity of the mud shows a downward trend, and the funnel viscosity is the largest when the borax content is 0.05%. In actual pipe jacking projects, when the viscosity of the mud is too high and the fluidity is low, it is not easy for the mud to penetrate into the soil layer. When the viscosity is too low, the mud cannot form a stable support in the soil layer. Considering economic benefits, the combination of A5B2C2D1 or A4B2C2D1 may be more appropriate.

[0056] 2. Analysis of the range of water loss (RA=17.4, RB=9.2, RC=9.2, RD=10):

[0057] According to Table 3 and Figure 2 Analysis shows that the water loss rate is the fastest when the bentonite content changes from 4% to 6%, and the water loss is the lowest when the bentonite sodium content is 8%. The water loss is the lowest when the PAM content is 0.20%, and its content change has little effect on the water loss. And when the guar gum content is greater than 0.10%, the water loss gradually increases. When the borax content is 0.25%, the water loss is the lowest. Excessive water loss of the mud will lead to water loss of the mud, weaken the wall protection effect of the mud, and reduce the stability of the soil layer. Excessive water loss of the mud will reduce the viscosity and shear force of the mud, and increase the difficulty of pumping the mud during the jacking process. Therefore, the combination of A3B2C2D1 or A3B2C4D1 is more suitable.

[0058] 3. Analysis of the extreme difference of water separation rate (RA=37.60%, RB=3.70%, RC=3.40%, RD=3.70%):

[0059] According to Table 3 and Figure 3 From the change of water separation rate, it can be seen that bentonite has the most significant effect on the water separation rate of mud. When the bentonite content is 10%, the water separation rate of mud reaches the lowest value. The increase of guar gum and PAM content can reduce the water separation rate of mud. The amount of borax has little effect on the water separation rate. When the borax content is 0.1%, the water separation rate is the lowest. Considering the stability of mud and the phenomenon of sediment sinking and water floating during transportation. Combined with the economic cost and the general water separation rate needs to be controlled above 98%, A4B2C3D2 may be the best combination.

[0060] 4. Dynamic shear force range analysis (RA = 4.1, RB = 2.0, RC = 0.7, RD = 0.7):

[0061] According to the range analysis in Table 3 and Figure 4It can be seen from the dynamic shear force that the increase in the content of the four factors can increase the dynamic shear force of the mud. Among them, guar gum, PAM, and borax show a slight upward trend. The dynamic shear force of the mud is the highest when the guar gum content is 0.25%, the polyacrylamide content is 0.25%, and the borax concentration is 0.25%. In the actual drilling construction of the jacking project, the mud needs to carry the drill cuttings and other solids to the ground, and the appropriate dynamic shear force helps the mud to carry the drill cuttings efficiently. Moreover, too high or too low dynamic shear force is not conducive to the stability of the pipe wall. The dynamic shear force is generally controlled at 0.5-15pa. So A5B5C5D5 may be a suitable combination.

[0062] 5. Analysis of the relationship between mud performance and bentonite content:

[0063] according to Figure 5 It can be seen that: with the increase of bentonite content, the mud parameters dynamic shear force, plastic viscosity, and apparent viscosity gradually increase, and the interaction force between bentonite and polymer also increases. The water loss of thixotropic mud decreases with the increase of sodium-based bentonite. When the bentonite content is greater than 6%, the change in the water loss of the mud is not large, which meets the requirement that the water loss of thixotropic mud is less than 25ml / 30min. When the bentonite content is 10%, the apparent viscosity, dynamic shear force, and plastic viscosity have met the slurry performance requirements, and increasing the bentonite content will improve the performance value to a lower value.

[0064] 6. Analysis of the relationship between mud properties and guar gum content:

[0065] according to Figure 6 It can be analyzed that when the content of guar gum in the mud is increased, the plastic viscosity, dynamic shear force and apparent viscosity of the thixotropic mud will also increase, because the higher the content of guar gum, the more dense the network structure will be formed by cross-linking reaction with borax, and the performance will be more stable. When the guar gum content is between 0.05% and 0.10%, the dynamic shear force changes at the fastest speed, and when the guar gum content is greater than 0.10%, the dynamic shear force changes less; and when the guar gum content is 0.10%, the water loss of the mud is the smallest.

[0066] 7. Analysis of the relationship between mud performance and PAM content:

[0067] according to Figure 7 It can be analyzed that when the PAM content in the mud is increased, the plastic viscosity, apparent viscosity, and dynamic shear force of the thixotropic mud all show a slight upward trend. This is because as the concentration of PAM increases, it reacts with bentonite to form a network structure, locking the water molecules in the bentonite, thereby enhancing the stability of the mud and increasing the viscosity of the mud. When the PAM content reaches 0.25%, the plastic viscosity reaches the maximum value. When the PAM content is 0.20%, the water loss of the thixotropic mud is the lowest and reaches the water loss index.

[0068] 8. Analysis of the relationship between mud performance and borax content:

[0069] according to Figure 8 It can be analyzed that: when the content of borax in the mud increases, the dynamic shear force, plastic viscosity and apparent viscosity also gradually increase, and each performance reaches the optimal value when the content is 0.25%. The mud water loss is the smallest when the borax content is 0.25%. Borax can react with guar gum in the slurry to form a three-membered ring structure, which improves the drag reduction performance and stability of the mud.

[0070] After analyzing the influence of various factors on mud performance parameters, it was concluded that there are two possible combinations, namely 10% bentonite, 0.1% guar gum, 0.15% PAM, 0.10% borax, 89.67% water and 10% bentonite, 0.1% guar gum, 0.10% PAM, 0.05% borax, 89.78% water. The mud with the two combinations has a small water loss, a water separation rate of 0, a high funnel viscosity, and a moderate dynamic shear force.

[0071] 2. In order to improve the accuracy of measurement, a test on the influence of a single factor on mud performance is specially set up.

[0072] 1. The influence of single control of bentonite content on mud performance

[0073] Bentonite and water were mixed into a simple slurry according to a certain ratio, and no admixture was added. The content of the single-control base bentonite was changed to 4%, 6%, 8%, 10%, 12%, 14% and water were fully mixed and the experimental measurement was carried out. The experimental results are shown in Table 4 and Fig. 9 As shown in Table 4, as the proportion of bentonite increases, the proportion of water decreases, the funnel viscosity gradually increases, and the water extraction rate gradually decreases. When the bentonite content reaches 10%, the change in the water extraction rate is small when the bentonite content is increased, so the 10% bentonite is selected for the highest benefit. Analysis shows that when bentonite is used alone to prepare thixotropic mud, the water extraction rate of the thixotropic mud is not 0, and the performance does not meet the pipe jacking construction standards, so it is necessary to add admixtures to change the performance of the mud.

[0074] Table 4 Effect of bentonite content change on mud properties

[0075]

[0076] Experimental experience shows that when bentonite is mixed with water without adding admixtures, a large amount of bentonite residue will remain on the bottom and wall of the mixer and fail to mix into the water. Moreover, the residue increases with the increase of bentonite content. Therefore, using bentonite alone as thixotropic mud cannot be used for pipe jacking construction.

[0077] 2. Effect of single control of guar gum content on mud properties

[0078] According to the results of orthogonal test range analysis, the guar gum content was controlled to explore the effect on the viscosity, water loss and water separation rate of the mud funnel. Fig.10 shown.

[0079] Table 5 Effect of guar gum content change on mud properties

[0080]

[0081] Combination Fig.10 It is analyzed that the proportion of guar gum in the mud gradually increases, the water loss and water extraction rate of the thixotropic mud gradually decrease, and the funnel viscosity of the mud shows an upward trend. The water loss and water extraction rate decrease fastest in the stage of guar gum from 0% to 0.10%. When the guar gum content is less than 0.1%, the water extraction rate of the mud is not 0, and water extraction stratification will occur. When it is greater than 0.10%, the water extraction rate is constant at 0, and the decrease in water loss is almost unchanged. In the mud proportioning process, guar gum has a high water-absorbent resin under weak alkaline conditions. After absorbing water, the volume can quickly expand to hundreds to thousands of times the original. The figure shows that when the dosage of guar gum is 0.10%, the water extraction rate has reached the lowest value, and even if guar gum is added, the improvement of mud performance is relatively low. Considering the construction cost comprehensively, the content of guar gum in the mud should not be less than 0.10%. In summary, bentonite: guar gum = 10%: 0.10%.

[0082] 3. Effect of single control of polyacrylamide (PAM) content on mud performance

[0083] The 10% bentonite and 0.1% guar gum determined by the above analysis were used as the quantitative, and the content of PAM was controlled alone. The effect on funnel viscosity, water loss, and water separation rate was investigated. The test results are as follows:

[0084] Table 6 Effect of PAM content change on mud properties

[0085]

[0086]

[0087] Combination Fig.11It is analyzed that as the PAM content in the mud increases, the water loss of the mud gradually decreases, the funnel viscosity gradually increases, and the water separation rate always remains zero. From a chemical point of view, the chemical reaction between bentonite and PAM inside the mud generates a dense network structure, which locks the free bentonite particles, increases the slurry consistency, and further improves the fluidity and impermeability of the mud, so that the mud reduces water loss and increases funnel viscosity. On the premise of ensuring that the funnel viscosity and water loss meet the standards and considering the economic cost, bentonite: guar gum: PAM = 10%: 0.1%: 0.15% is selected.

[0088] 4. The influence of single control of borax content on mud performance

[0089] The 10% bentonite, 0.1% guar gum, and 0.15% polyacrylamide determined by the above analysis were used as the quantitative, and the borax content was controlled alone. The effects on the funnel viscosity, water loss, and water separation rate were investigated. The test results are as follows:

[0090] Table 7 Effect of Borax Content Change on Mud Performance

[0091]

[0092] Combination Fig.12 The analysis shows that increasing the content of borax in the mud has a significant effect on the funnel viscosity. From a chemical point of view, the borax and guar gum in the mud system undergo a cross-linking reaction to generate a special three-membered ring structure attached to the surface of the bentonite, thereby increasing the funnel viscosity. However, the change in borax content has little effect on the water loss. On the premise of meeting the performance standards, combined with economic cost as the final consideration, 10% bentonite, 0.10% guar gum, 0.15% PAM, 0.10% borax, and 89.69% water are selected as the optimal ratio.

[0093] The beneficial effects of the present invention are as follows: the drag-reducing mud for trenchless pipe jacking construction and the preparation method are prepared by sequentially blending a certain proportion of bentonite, guar gum, PAM and borax into the influent water, and adjusting the pH value and the temperature; the admixture PAM can interact with the bentonite and form a dense network structure, thereby improving the performance of the mud, thereby obtaining the pipe jacking drag-reducing mud with excellent drag-reducing effect, standard impermeability, stable structure, moderate viscosity, and optimal indicators, thereby meeting the needs of pipe jacking construction.

[0094] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A drag-reducing slurry for trenchless pipe jacking construction, characterized in that: The raw materials include the following component proportions: the slurry components include 85-95% water, 6-10% bentonite, 0.05-0.15% guar gum, 0.1-0.25% PAM and 0.1-0.25% borax.

2. The drag reducing slurry for trenchless pipe jacking construction according to claim 1, characterized in that: The components include 89.65% water, 10% bentonite, 0.1% guar gum, 0.15% PAM, and 0.1% borax. The bentonite component includes 70% montmorillonite, 20% illite, 5% kaolinite, and a small amount of halloysite, zeolite, quartz, and feldspar.

3. The drag reducing slurry for trenchless pipe jacking construction according to claim 1, characterized in that: The slurry components include 91.55% water, 8% bentonite, 0.15% guar gum, 0.15% PAM, and 0.15% borax.

4. The drag reducing slurry for trenchless pipe jacking construction according to claim 1, characterized in that: The slurry components include 93.7% water, 6% bentonite, 0.1% guar gum, 0.1% PAM, and 0.1% borax.

5. A method for preparing drag-reducing mud for trenchless pipe jacking construction, using the drag-reducing mud for trenchless pipe jacking construction according to any one of claims 1 to 4, characterized in that: The following steps are involved: 1) First, add pure water into the container and heat it to a certain extent; 2) Add bentonite, stirring while adding, and stir evenly to make a solution; 3) Add soda ash or caustic soda to the solution to adjust the pH value of the solution to 8-10; 4) Add guar gum and PAM in sequence and stir evenly to obtain diversified and excellent polymers; 5) Finally, add borax and stir evenly. Borax and guar gum will undergo a cross-linking reaction to form an elastic gel.

6. The method for preparing drag-reducing slurry for trenchless pipe jacking construction according to claim 5, characterized in that: In the step 2), the bentonite needs to be ground into powder, sieved and weighed, and then slowly added into the container after weighing.

7. The method for preparing drag-reducing slurry for trenchless pipe jacking construction according to claim 5, characterized in that: In the step 3), soda ash and caustic soda are weighed, one of them is selected and gradually added to the solution, stirring is performed continuously, and the pH value is measured using a test paper.

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