阅读说明：本技术 一种用于堤坝防渗加固的循环保压多轮次注浆方法 (Circulating pressure-maintaining multi-turn grouting method for dam seepage-proofing reinforcement ) 是由 郭成超 王超杰 石明生 赵鹏 赵线峰 薛冰寒 王颖丽 夏洋洋 刘琪 黄光营 于 2020-06-30 设计创作，主要内容包括：本发明属于水利基础涉及防渗加固技术领域,具体涉及一种用于堤坝防渗加固的循环保压多轮次注浆方法。包括以下步骤：确定需要处置的渗透层位置；在堤坝顶部靠近迎水面布孔,然后用钻机钻取注浆孔；将注浆管置于注浆孔内,封孔管短于注浆管,在封孔管下方设置有隔离块；往封孔注浆管中注入膨胀料进行封孔保压；使用循环保压多轮次注浆法进行渗透型高聚物的注浆,注浆压力为0.5～2Mpa。本发明方法施工便捷、工期较短、对堤坝扰动小、防渗效果好、耐久性强,利于浆液充分渗透扩散,且可有效降低注浆过程的主观性和经验性,可指导注浆施工。(The invention belongs to the technical field of seepage-proofing reinforcement of water conservancy foundations, and particularly relates to a circulating pressure-maintaining multi-turn grouting method for seepage-proofing reinforcement of a dam. The method comprises the following steps: determining the position of a permeable layer needing to be treated; arranging holes on the top of the dam close to the upstream surface, and drilling grouting holes by using a drilling machine; placing the grouting pipe in the grouting hole, wherein the hole sealing pipe is shorter than the grouting pipe, and a spacer block is arranged below the hole sealing pipe; injecting an expansion material into the hole sealing grouting pipe to seal holes and maintain pressure; and (3) grouting the permeable high polymer by using a cyclic pressure-maintaining multi-turn grouting method, wherein the grouting pressure is 0.5-2 Mpa. The method has the advantages of convenient construction, short construction period, small disturbance to the dam, good anti-seepage effect and strong durability, is beneficial to full permeation and diffusion of the slurry, can effectively reduce the subjectivity and the experience of the grouting process, and can guide grouting construction.)

1. A circulation pressure-maintaining multi-turn grouting method for dam seepage-proofing reinforcement is characterized by comprising the following steps:

A. determining and marking the position of the permeation layer to be treated;

B. arranging holes on the top of the marked dam close to the upstream face in a curtain grouting mode, and drilling grouting holes by using a drilling machine;

C. placing and fixing a grouting pipe in a grouting hole, wherein the grouting pipe comprises a penetration grouting pipe and a hole sealing grouting pipe, the hole sealing grouting pipe is shorter than the penetration grouting pipe, and an isolation block is arranged below the hole sealing grouting pipe;

D. injecting an expansion material into the hole sealing grouting pipe to seal holes and maintain pressure;

E. and (3) grouting the permeable high polymer by using a cyclic pressure-maintaining multi-turn grouting method, wherein the grouting pressure is 0.5-2 Mpa.

2. The method for cyclic pressure maintaining and multi-turn grouting for dam seepage prevention and reinforcement according to claim 1, wherein the distance between every two grouting holes is 0.5-1 m, and the diameter of the grouting hole is 2-30 cm.

3. The method for cyclic pressure-maintaining multi-turn grouting for seepage-proofing reinforcement of dams according to claim 1, wherein the isolation blocks are waste plastic bags or gloves.

4. The method for cyclic pressure maintaining and multi-turn grouting for seepage-proofing reinforcement of dams according to claim 1, wherein a three-way pipe is installed at the top of the seepage grouting pipe, a valve switch is installed on the three-way pipe, one end of the three-way pipe is connected with the seepage grouting pipe, the other end of the three-way pipe is connected with a grouting gun, and a pressure gauge is installed at the middle end of the three-way pipe.

5. The method for cyclic pressure-maintaining multi-turn grouting for seepage-proofing reinforcement of dams according to claim 4, characterized in that the lower end of the seepage grouting pipe is provided with grout outlet holes with the distance of 0.5 m.

6. The method for circulating pressure-maintaining multi-turn grouting for dam seepage-proofing reinforcement according to claim 1, characterized in that the swelling material is formed by mixing rosin polyester polyol, isocyanate, Phireguard MB-512, 1-dichloro-1-fluoroethane, surfactant, catalyst and benzoyl chloride.

7. The method for cyclic pressure-maintaining multi-turn grouting for dam seepage-proofing reinforcement according to claim 1, characterized in that the relationship between the grouting amount of the swelling material and the diameter of the grouting hole is as follows: the grouting amount is 1.5kg when the diameter is less than 5cm, 3kg when the diameter is 5-15 cm, and 8kg when the diameter is more than 15 cm.

8. The method for cyclic pressure-maintaining multi-turn grouting for seepage-proofing reinforcement of dams according to claim 1, wherein the permeable high polymer comprises a material A and a material B, the material A is composed of hydrophilic low-viscosity polyether polyol, osmotic diluent, surfactant and catalyst, and the material B is composed of isocyanate, osmotic diluent and flame retardant.

9. The cyclic pressure-maintaining multi-turn grouting method for seepage-proofing reinforcement of dams according to claim 1, characterized in that the cyclic pressure-maintaining multi-turn grouting method is specifically operated as follows: and (3) injecting the permeable high polymer into the grouting holes through the permeable grouting pipes, stopping grouting when the pressure reaches 2MPa, ending the first round at the moment, repeating the steps to perform the second round of grouting if the pressure is reduced to be below 0.5MPa after 30min, and ending the grouting until the pressure is still above 0.5MPa after 30 min.

Technical Field

The invention belongs to the technical field of seepage-proofing reinforcement of water conservancy infrastructure, and particularly relates to a circulating pressure-maintaining multi-turn grouting method for seepage-proofing reinforcement of a dam.

Background

In recent years, the construction of water conservancy infrastructure in China has gained much attention. At present, the total length of the built dikes reaches 41 kilometers, 9.8 thousands of reservoirs of various types are important components in the field of flood control and disaster reduction in China, however, the dikes in China have a long construction history, are formed by increasing the thickness of the dikes in years, have insufficient building quality, have many hidden dangers, are complex in geological conditions and are frequently in flood season. Similarly, in the constructed reservoir, the risk rate reaches 57.1%, and most small and medium-sized risk reservoirs need seepage-proofing reinforcement. Once the water conservancy facilities are lost, the influence is great, and the life and property safety of people is seriously threatened. Therefore, the seepage-proofing reinforcing technology and equipment level of the water conservancy infrastructure are urgently needed to be improved.

The prior seepage-proofing reinforcing technology comprises a concrete seepage-proofing wall, a cement-soil mixing pile, a high-pressure jet grouting technology and the like, however, the common problems of the technologies comprise great disturbance damage to a dam, long construction period, insufficient efficiency, huge equipment, inconvenient construction, overlarge wall thickness and the like, and further application of the technologies is limited. On the other hand, grouting materials such as cement paste, cement clay paste, ultra-fine cement paste and other various modified cement pastes are the main materials in various engineering practices at present. But the further application of the polyurethane foam is limited by the defects of long coagulation time, easy segregation, shrinkage cracking, high rigidity and the like. Chemical grouting is developed on the basis of suspension grouting. The chemical slurry mainly comprises water glass, acrylamide, lignin, epoxy resin, chromium lignin, urea-formaldehyde resin and the like. However, the above materials have poor consolidation effect with soil, insufficient impermeability of the consolidated body and poor durability, can cause certain pollution to the environment, and also influence the seepage-proofing and reinforcing effect of the materials on the dam.

At present, the high polymer grouting technology is widely applied in the fields of water conservancy, mines, traffic and the like, and is injected into cracks or holes by utilizing the characteristic of quick response and quick expansion, so that the aim of seepage prevention and leakage stoppage is fulfilled. In recent years, aiming at the defects of the existing dam and reservoir seepage-proofing reinforcing technology in China, methods such as a high polymer curtain grouting technology (such as Chinese patent CN101638987A), a dam seepage-proofing high polymer directional splitting grouting method (such as Chinese patent CN102051868A), an ultrathin high polymer seepage-proofing wall forming method and the like are successively provided from a flexible seepage-proofing concept, wherein the ultrathin high polymer seepage-proofing wall technology enables high polymers to form a continuous and uniform seepage-proofing wall in a manner of static pressure grooving and lifting grouting. However, the grouting material used in the technology is an expansion type high polymer, and is characterized by large viscosity, fast reaction and easy expansion, which leads to the limited distance of the material penetrating into the soil body, and further leads to the difficulty of fully cementing with the soil body to form a consolidated body, and finally only cleavage grouting can be carried out. On the other hand, the dykes or dams are divided into two parts regardless of cement concrete impervious walls or high polymer impervious walls, so that the stability of the dykes can be influenced to a certain extent.

Meanwhile, the existing continuous one-time grouting method is not beneficial to full diffusion of the grout, the diffusion of the grout in the soil body pore space is influenced by the viscous resistance of air in the pore space, the air pressure in the pore space cannot be dissipated due to large-flow continuous grouting, the grout cannot be diffused to a longer distance, when the pressure in a grouting hole rises, if the grouting is stopped, the grout diffusion effect is poor, the preset seepage-proofing reinforcing area cannot be finished, and if the grouting is continued, the seepage diffusion is converted into splitting diffusion, so that the dam is damaged to a certain extent. In addition, the existing grouting construction is judged according to the experience of operators, the uncertainty is large, whether grouting is finished or not cannot be judged, if grouting is finished or not only by controlling the grouting amount, the construction quality cannot be guaranteed, and the final seepage-proofing reinforcing effect is poor.

Disclosure of Invention

The invention provides a circulating pressure-maintaining multi-turn grouting method for dam seepage-proofing reinforcement, which aims to solve the defects that the existing dam seepage-proofing reinforcement technology is long in construction period, huge in equipment and inconvenient in construction, grouting completion is difficult to determine, the diffusion distance of slurry is insufficient, and the seepage-proofing reinforcement effect is poor.

In order to achieve the purpose, the invention adopts the following technical scheme:

A circulation pressure-maintaining multi-turn grouting method for dam seepage-proofing reinforcement comprises the following steps:

A. determining the position of a permeable layer needing to be treated;

B. arranging holes on the top of the dam close to the upstream face in a curtain grouting mode, and drilling grouting holes by using a drilling machine;

C. placing and fixing a grouting pipe in a grouting hole, wherein the grouting pipe comprises a penetration grouting pipe and a hole sealing grouting pipe, the hole sealing grouting pipe is shorter than the penetration grouting pipe, and an isolation block is arranged below the hole sealing grouting pipe;

D. injecting an expansion material into the hole sealing grouting pipe to seal holes and maintain pressure;

E. grouting the permeable high polymer by using a cyclic pressure-maintaining multi-turn grouting method, wherein the grouting pressure is 0.5-2 Mpa;

furthermore, the distance between every two grouting holes is 0.5-1 m, and the diameter of each grouting hole is 2-30 cm.

Further, the isolation blocks are waste plastic bags or gloves.

Furthermore, a three-way pipe is arranged at the top of the seepage grouting pipe, a valve switch is arranged on the three-way pipe, one end of the three-way pipe is connected with the seepage grouting pipe, one end of the three-way pipe is connected with a grouting gun, and a pressure gauge is arranged at one end of the middle of the three-way pipe.

Furthermore, the lower end of the permeation grouting pipe is provided with a grout outlet, and the distance between the openings is 0.5 m.

Further, the expanded material is prepared by mixing rosin polyester polyol, isocyanate, Phireguard MB-512, 1-dichloro-1-fluoroethane, a surfactant, a catalyst and benzoyl chloride.

Further, the relationship between the grouting amount of the expansion material and the diameter of the grouting hole is as follows: the grouting amount is 1.5kg when the diameter is less than 5cm, 3kg when the diameter is 5-15 cm, and 8kg when the diameter is more than 15 cm.

Further, the permeable polymer comprises a material A and a material B, wherein the material A consists of hydrophilic low-viscosity polyether polyol, a permeable diluent, a surfactant and a catalyst, and the material B consists of

Penetrating diluent and flame retardant.

Further, the concrete operation of the circulation pressure maintaining multi-round grouting method is as follows: and (3) injecting the permeable high polymer into the grouting holes through the permeable grouting pipes, stopping grouting when the pressure reaches 2MPa, ending the first round at the moment, repeating the steps to perform the second round of grouting if the pressure is reduced to be below 0.5MPa after 30min, and ending the grouting until the pressure is still above 0.5MPa after 30 min.

Compared with the prior art, the invention has the following beneficial effects:

the method comprises the steps of firstly, carrying out pressure-maintaining hole sealing on a grouting hole by using a hole-sealing grouting pipe and an expansion material, arranging an isolation block below the hole-sealing grouting pipe to prevent liquid in the hole-sealing grouting pipe from flowing downwards, and closely attaching the injected expansion material to the grouting pipe and the surrounding soil wall after ten seconds to enhance the sealing effect; the permeable high polymer has the effects of non-foaming, low viscosity, high permeability, slow reaction and strong consolidation, fully permeates into tiny pores of soil bodies, bonds the soil bodies together, fills the pores, and enables the originally loose soil bodies to be agglomerated together to form a consolidated body with higher impermeability and strength, thereby improving the impermeability and stability of the dam. The dam pore space is filled and reinforced in a closed environment, whether grouting is finished or not is judged by utilizing the pressure gauge at the upper end of the grouting hole, huge equipment is not needed, simplicity and effectiveness are achieved, the cyclic pressure maintaining multi-turn grouting method is beneficial to full diffusion filling of grout, swelling materials and permeable polymers are quickly condensed with surrounding soil, and the construction period is shortened. The permeable high polymer adopted by the invention has low viscosity and quick permeability, so the slurry has large diffusion distance and good consolidation effect, the method has small disturbance to the dam, good seepage-proofing effect and strong durability, can effectively reduce the subjectivity and the experience of the grouting process, and can guide grouting construction.

Drawings

FIG. 1 is a schematic view of cross-hole distribution in example 1;

FIG. 2 is a longitudinal schematic view of a borehole according to example 1;

FIG. 3 is a schematic view of a permeate slip pipe according to example 1;

FIG. 4 is a schematic view of hole sealing and grouting in example 1;

FIG. 5 is a graph showing the effect of the slurry of example 1;

FIG. 6 is a plan view of a DCP test point and model test of example 2;

FIG. 7 is a graph of the results of the DCP test of example 2;

FIG. 8 is a graph showing the results of the sample seepage test in example 2;

FIG. 9 shows the dipole-dipole 32-electrode detection inversion results of the soil mass before grouting in example 3;

FIG. 10 shows the dipole-dipole 60 electrode detection inversion results of the soil mass before grouting in example 3;

FIG. 11 is the inversion result of dipole-dipole 32-electrode detection of the soil mass after grouting in example 3;

FIG. 12 shows the dipole-dipole 60 electrode detection inversion results of the soil mass after grouting in example 3.

Reference is made to figures 1 to 5: 1 is the upstream face, 2 is the slip casting hole, 3 is the surface of a poor water, 4 is the hole sealing slip casting pipe, 5 is the infiltration slip casting pipe, 51 is the slip casting hole, 6 is the spacer block, 7 is the three-way pipe, 8 is the slip casting rifle, 9 is the manometer, 10 is the valve.

Detailed Description

The invention will be further explained with reference to the figures and specific embodiments.