Concrete for grouting bottom sealing under strong flow conditions in foundation pits in broken zones and its construction method

Abstract

The present application relates to the field of subway construction, and more specifically, it relates to concrete and construction methods for grouting bottom sealing under strong flow conditions in foundation pits in broken zones. A concrete for grouting bottom sealing under strong flow conditions in foundation pits in broken zones, comprising: silicate cement, admixtures, coarse aggregate, fine aggregate, water reducer, water, Wenlun glue, sodium carboxymethyl hydroxyethyl cellulose, and accelerator; the accelerator is a mixture of aluminum sulfate, polyaluminum sulfate, and calcium carbonate; its construction method is: Step 1): excavation of foundation pit; Step 2): support pile construction; Step 3): bottom sealing: pile positions are set at the bottom of the corresponding working area of ​​the foundation pit, and rotary grouting piles are formed by rotary grouting, and the rotary grouting piles form a substantially closely packed hexagonal or plum blossom array that interlocks with each other, and a sealing bottom layer composed of rotary grouting piles is formed at the bottom of the corresponding working area of ​​the foundation pit. The present application has the advantage of ensuring the integrity of the sealing bottom layer.

Description

Technical Field

[0001] The present application relates to the field of subway construction, and more specifically, to concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone and a construction method. Background Art

[0002] With the rapid economic development, underground construction such as subways and tunnels are being applied in more and more places in densely populated cities where land is becoming increasingly scarce. Inevitably, there will be situations where it is necessary to construct the foundation pit of a subway station in the fault fracture zone. Since the rock in the fracture zone is very soft and has developed cracks, it softens when it comes into contact with water, making it difficult to construct.

[0003] At present, it is necessary to carry out operations in the fractured zone, usually by grouting the bottom of the foundation pit. Generally, ordinary cement slurry or cement and water glass double liquid slurry is used for grouting. However, when ordinary cement slurry or double liquid slurry is poured, it is easily affected by the strong flowing water flow in the fractured zone, and it is carried away by the water flow before solidification, which affects the integrity of the bottom sealing layer and further affects the subsequent construction. Therefore, there is still room for improvement. Summary of the invention

[0004] In order to ensure the integrity of the bottom sealing layer, the present application provides concrete and a construction method for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone.

[0005] In the first aspect, the present application provides a concrete for grouting bottom sealing in a strong flow condition in a foundation pit in a broken zone, which adopts the following technical solution:

[0006] A concrete for grouting bottom sealing in a broken zone foundation pit under strong flow conditions, comprising the following raw materials: 360-390 parts of silicate cement, 40-80 parts of admixture, 1000-1200 parts of coarse aggregate, 600-750 parts of fine aggregate, 3-7 parts of water reducer, 145-160 parts of water, 0.5-3 parts of warm wheel glue, 1.5-3.5 parts of sodium carboxymethyl hydroxyethyl cellulose, and 2-6 parts of accelerating agent;

[0007] The accelerating setting agent is a mixture of aluminum sulfate, polyaluminum sulfate and calcium carbonate.

[0008] The quick-setting agent adopts a combination of aluminum sulfate, polyaluminum sulfate, and calcium carbonate, which forms a specific combination with Wenlun glue and sodium carboxymethyl hydroxyethyl cellulose. The prepared concrete has a certain consistency and is not easily dispersed or carried away by strong flowing water when poured into the foundation pit. In addition, the concrete provided in this application can be solidified in a short time after being poured into the foundation pit, which also reduces the degree of being affected by the water flow. The sealing layer prepared by this concrete is quickly solidified and formed in the early stage, which reduces waste and shortens the pouring time. The strength is also improved in the later stage, forming a complete, high-strength and stable sealing layer, which is convenient for subsequent operations.

[0009] Specifically, a specific accelerator reacts rapidly with calcium ions produced by the hydrolysis of cement clinker to generate needle-shaped and rod-shaped AFt, which rapidly and continuously overlap and grow in the system to form a spatial network structure, accelerating the setting of concrete. In addition, with the cooperation of the accelerator, Wenlun glue, and sodium carboxymethyl hydroxyethyl cellulose, the viscosity and toughness of the introduced bubble liquid are improved, the aggregation between bubbles is reduced, thereby reducing the interference of bubbles on the generation of the spatial network structure, providing better rapid overlapping conditions for the spatial network structure. This cooperation also improves the ability of Wenlun glue to adsorb water molecules, so that part of the infiltrated groundwater can be fixed by the Wenlun glue, reducing the interference of groundwater on the structure of the early concrete; and during the later maintenance, some of the adsorbed water molecules can be slowly released, prolonging the time of the hydration reaction, thereby improving the strength of the concrete in the later stage.

[0010] Generally speaking, the use of accelerators will reduce the later strength of concrete. However, in practice, it is found that the later strength of the concrete in this application is improved. On the one hand, it is related to the above-mentioned fixed groundwater. On the other hand, it may be because the system provided by this application has a good improvement in the toughness and distribution of bubbles, and optimizes the pore structure, which is conducive to improving the later strength of concrete.

[0011] Preferably, the accelerator comprises the following raw materials in parts by mass: 30-50 parts of aluminum sulfate, 30-60 parts of polyaluminum sulfate, 80-150 parts of calcium carbonate, 0.1-0.5 parts of activator, and 1-5 parts of water reducer.

[0012] By adopting the above technical solution, the specific composition of the accelerating agent is further limited. When the accelerating agent is added to the concrete system, it can quickly provide a large amount of sulfate ions and aluminum ions to the cement slurry, react with the calcium ions in the cement slurry, and finally generate a large amount of Aft, which promotes the coagulation of the concrete system. In addition, with the cooperation of aluminum sulfate, polyaluminum sulfate and calcium carbonate, the carbon aluminate in the system can be increased as a nucleation site for the precipitation of hydration products of sulfoaluminate, thereby improving the degree of hydration and the early strength of concrete.

[0013] Preferably, the mass ratio of the aluminum sulfate, polyaluminum sulfate and calcium carbonate is 1:(1.0-1.5):(2-3), based on the mass of aluminum sulfate.

[0014] By adopting the above technical scheme, the mass ratio of aluminum sulfate, polyaluminum sulfate and calcium carbonate is further limited, so that the amount of sulfate ions is not too much, the excess dihydrate gypsum in the system is reduced, and an appropriate amount of calcium sulfoaluminate hydrate is generated, which is beneficial to the improvement of the later concrete strength and the stability of the bottom sealing layer.

[0015] Preferably, the preparation method of the accelerating setting agent comprises the following steps: mixing aluminum sulfate, polyaluminum sulfate and calcium carbonate, sintering at 800-950° C. for 30-60 min, and then mixing with an activator and a water reducing agent, grinding, and obtaining an accelerating setting agent.

[0016] By adopting the above technical solution, sintering is carried out at a specific temperature, which is conducive to stimulating the coordination between the raw materials. In addition, the powdered quick-setting agent is obtained, which is convenient for carrying and storage.

[0017] Preferably, the mass ratio of the wet wheel glue, sodium carboxymethyl hydroxyethyl cellulose and accelerating agent is (1.5-2.5): (1.8-2.3): (3-5).

[0018] By adopting the above technical scheme, the mass ratio of Wenlun glue, sodium carboxymethyl hydroxyethyl cellulose and accelerating agent is further limited, which is beneficial to further improve the toughness and strength of bubbles and optimize the pore structure, thereby improving the setting speed and later strength of concrete.

[0019] Preferably, the admixture includes a mixture of one or more of fly ash, silica fume, limestone and slag powder.

[0020] Preferably, the admixtures are limestone, silica fume and slag powder, and the mass ratio of limestone, silica fume and slag powder is 1:(0.3-0.6):(0.1-0.3), with the mass ratio of limestone as the benchmark.

[0021] Preferably, the method for preparing the concrete comprises the following steps:

[0022] Mixing silicate cement and admixtures, and then adding water and mixing until uniform to obtain cement slurry;

[0023] Then, the coarse aggregate and the fine aggregate are mixed evenly to obtain the material to be used;

[0024] The material to be used is mixed with cement slurry, and then warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose and accelerating setting agent are added and mixed together until uniform to obtain a finished product.

[0025] In the second aspect, the present application provides a construction method for grouting bottom sealing in a strong flow condition in a foundation pit in a broken zone, which adopts the following technical solution:

[0026] A construction method for grouting bottom sealing in a strong flow condition in a broken zone foundation pit, comprising the following steps:

[0027] Step 1): Excavation of foundation pit: excavate the foundation pit to a specified depth;

[0028] Step 2): Support pile construction: Support piles are set up around the foundation pit, and the area surrounded by the support piles is the working area; Step 3): Bottom sealing: Pile positions are set up at the bottom of the foundation pit corresponding to the working area, and rotary grouting piles are formed by rotary grouting. The rotary grouting piles form a roughly closely packed hexagonal or plum blossom array that interlocks with each other, and a sealing layer composed of rotary grouting piles is formed at the bottom of the foundation pit corresponding to the working area.

[0029] By adopting the above technical solution, a sealing layer is set at the bottom of the corresponding working area of ​​the foundation pit, and a specific concrete is used for pouring. Concrete with a certain consistency solidifies quickly and is not easily carried away by strong flowing water. A complete sealing layer is quickly formed to facilitate subsequent operations.

[0030] Preferably, the outer side edge of the bottom sealing layer abuts against the inner side surface of the supporting pile.

[0031] By adopting the above technical solution, the sealing layer is in contact with the inner side of the supporting pile, which further reduces the external groundwater from entering the working area, making the operation easier. At the same time, reducing the infiltration of groundwater also helps to reduce the impact of groundwater on concrete.

[0032] In summary, this application has the following beneficial effects:

[0033] 1. This application sets a sealing layer at the bottom of the corresponding working area of ​​the foundation pit and uses specific concrete pouring. The concrete with a certain consistency solidifies quickly and is not easily carried away by strong flowing water. A complete sealing layer is quickly formed to facilitate subsequent operations.

[0034] 2. The concrete provided in this application can effectively improve the viscosity and toughness of the introduced bubble liquid, reduce the aggregation between bubbles, thereby reducing the interference of bubbles on the generation of spatial network structure, providing better rapid lap conditions for the spatial network structure and faster solidification.

[0035] 3. The concrete provided by the present application also improves the ability of the thermoplastic adhesive to absorb water molecules, so that part of the seeping groundwater can be fixed by the thermoplastic adhesive, reducing the structural interference of the groundwater on the early concrete; and during the later maintenance, part of the adsorbed water molecules can be slowly released, prolonging the time of the hydration reaction, thereby improving the later strength of the concrete. DETAILED DESCRIPTION

[0036] The present application is further described in detail below with reference to the embodiments.

[0037] The raw materials used in the following examples and comparative examples are all commercially available products.

[0038] Preparation Example

[0039] Preparation Example 1

[0040] A quick-setting agent comprises the following raw materials: 40kg of aluminum sulfate, 48kg of polyaluminum sulfate, 100kg of calcium carbonate, 0.3kg of activator and 0.2kg of water reducing agent.

[0041] The activator is sodium dodecyl sulfate and the water reducer is a polycarboxylic acid water reducer.

[0042] A method for preparing an accelerating setting agent comprises the following steps:

[0043] Step 01): Weigh the raw materials according to the amounts in Table 1.

[0044] Step 02): Aluminum sulfate, polyaluminum sulfate and calcium carbonate are added into the reaction kettle and mixed evenly, and then sintered at 950° C. for 30 minutes.

[0045] Step 03): Add activator and water reducer to the material in step 02) and mix until uniform. Grind until the Blaine surface area is 350m 2 / kg, to obtain quick-setting agent.

[0046] Preparation Example 2

[0047] A quick-setting agent, which is different from Preparation Example 1 in that the mass ratio of aluminum sulfate, polyaluminum sulfate and calcium carbonate is 1:1.0:3, that is, the usage amount of aluminum sulfate is 40kg, the usage amount of polyaluminum sulfate is 40kg, and the usage amount of calcium carbonate is 120kg.

[0048] A method for preparing an accelerating setting agent, which is different from Preparation Example 1 in that: in step 02), sintering is performed at 800° C. for 60 minutes.

[0049] Preparation Example 3

[0050] A quick-setting agent, which is different from Preparation Example 1 in that the mass ratio of aluminum sulfate, polyaluminum sulfate and calcium carbonate is 1:1.5:2, that is, the amount of aluminum sulfate used is 40kg, the amount of polyaluminum sulfate used is 60kg, and the amount of calcium carbonate used is 80kg.

[0051] Preparation Example 4

[0052] A quick-setting agent, which is different from Preparation Example 1 in that the mass ratio of aluminum sulfate, polyaluminum sulfate and calcium carbonate is 1:0.8:3.75, that is, the amount of aluminum sulfate used is 40kg, the amount of polyaluminum sulfate used is 32kg, and the amount of calcium carbonate used is 150kg.

[0053] Preparation Example 5

[0054] A quick-setting agent, which is different from Preparation Example 1 in that: the amount of aluminum sulfate used is 80 kg, the amount of polyaluminum sulfate used is 80 kg, and the amount of calcium carbonate used is 28 kg.

[0055] Preparation Example 6

[0056] A method for preparing an accelerating setting agent, which is different from Preparation Example 1 in that: in step 02), sintering is performed at 1200°C.

[0057] Example

[0058] Example 1

[0059] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone comprises the following raw materials: silicate cement, admixture, coarse aggregate, fine aggregate, water reducing agent, water, warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose and accelerating setting agent.

[0060] The admixtures are limestone, silica fume and slag powder, which are mixed in a ratio of 1:0.5:0.3.

[0061] The coarse aggregate is crushed gravel with an average particle size of 10-20 mm.

[0062] The fine aggregate is river sand with an average particle size of 0.25-0.5mm.

[0063] The water reducing agent is a polycarboxylic acid water reducing agent.

[0064] The quick-setting agent used was the quick-setting agent prepared in Preparation Example 1.

[0065] The specific amount of each raw material is shown in Table 1.

[0066] A method for preparing concrete for grouting bottom sealing in a broken zone foundation pit under strong flow conditions comprises the following steps:

[0067] Step a): Mix silicate cement and admixtures until uniform, then add water and mix until uniform to obtain cement slurry.

[0068] Step b): Mix the coarse aggregate and the fine aggregate until uniform to obtain the material to be used.

[0069] Step c): the material to be used is mixed with cement slurry until uniform; then the warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose and accelerating agent are added in sequence, and mixed together until uniform to obtain the finished product.

[0070] The present application also provides a method for grouting bottom sealing in a broken zone foundation pit under strong flow conditions, comprising the following steps:

[0071] Step 1): Excavation of foundation pit: Excavate the foundation pit to the specified depth according to the drawings.

[0072] Step 2): Support pile construction: Support piles are set up around the foundation pit, and the area surrounded by the support piles is the working area.

[0073] Step 3): Bottom sealing: Pile positions are set at the bottom of the corresponding working area of ​​the foundation pit, and the grouting holes are arranged in a 2*2m plum blossom shape. The above concrete is used and jet grouting is used to form jet grouting piles, and the jet grouting piles form a mutually interlocking plum blossom array. A sealing layer composed of jet grouting piles is formed at the bottom of the corresponding working area of ​​the foundation pit.

[0074] The outer side of the sealing layer is in contact with the inner side of the supporting pile to further reduce the groundwater infiltration into the working area.

[0075] Example 2

[0076] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone, which is different from Example 1 in that the quick-setting agent used is the quick-setting agent prepared by Preparation Example 2.

[0077] Example 3

[0078] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone, which is different from Example 1 in that the quick-setting agent used is the quick-setting agent prepared by Preparation Example 3.

[0079] Example 4

[0080] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone, which is different from Example 1 in that the quick-setting agent used is the quick-setting agent prepared by Preparation Example 4.

[0081] Example 5

[0082] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone, which is different from Example 1 in that the quick-setting agent used is the quick-setting agent prepared by Preparation Example 5.

[0083] Example 6

[0084] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone, which is different from Example 1 in that the quick-setting agent used is the quick-setting agent prepared by Preparation Example 6.

[0085] Example 7

[0086] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit of a broken zone, which is different from Example 1 in that the mass ratio of the warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose, and the accelerating agent is 1.5:2.3:3. That is, the amount of the warm wheel glue used is 1.5 kg, the amount of the sodium carboxymethyl hydroxyethyl cellulose used is 2.3 kg, and the amount of the accelerating agent used is 3 kg.

[0087] Example 8

[0088] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit of a broken zone, which is different from Example 1 in that the mass ratio of the warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose, and the accelerating agent is 2.5:1.8:5. That is, the amount of the warm wheel glue used is 2.5 kg, the amount of the sodium carboxymethyl hydroxyethyl cellulose used is 1.8 kg, and the amount of the accelerating agent used is 5 kg.

[0089] Example 9

[0090] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit of a broken zone, which is different from Example 1 in that the mass ratio of the warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose, and the accelerating agent is 3:3:2. That is, the amount of the warm wheel glue used is 3kg, the amount of the sodium carboxymethyl hydroxyethyl cellulose used is 3kg, and the amount of the accelerating agent used is 2kg.

[0091] Table 1

[0092]

[0093]

[0094] Comparative Example

[0095] Comparative Example 1

[0096] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone, which is different from Example 1 in that the Wenlun rubber is replaced by xanthan gum, that is, the usage amount of the Wenlun rubber is 0kg, and the usage amount of the xanthan gum is 2kg.

[0097] Comparative Example 2

[0098] A concrete for grouting bottom sealing under strong flow conditions in a broken zone foundation pit, which is different from Example 1 in that sodium carboxymethyl hydroxyethyl cellulose is replaced by hydroxyethyl cellulose, that is, the usage amount of sodium carboxymethyl hydroxyethyl cellulose is 0 kg, and the usage amount of hydroxyethyl cellulose is 2 kg.

[0099] Comparative Example 3

[0100] A concrete for grouting bottom sealing under strong flow conditions in a foundation pit in a broken zone, which is different from Example 1 in that the quick-setting agent of Preparation Example 1 is replaced by a commercially available J85 quick-setting agent, that is, the usage amount of the quick-setting agent of Preparation Example 1 is 0 kg, and the usage amount of the commercially available J85 quick-setting agent is 4 kg.

[0101] Comparative Example 4

[0102] A concrete for grouting bottom sealing under strong flow conditions in a broken zone foundation pit, which is different from Example 1 in that the amount of warm wheel glue used is 0.5kg, the amount of sodium carboxymethyl hydroxyethyl cellulose used is 0.5kg, and the amount of the quick-setting agent used in Preparation Example 1 is 7kg.

[0103] Performance testing

[0104] 1. Setting time: According to "4 Setting time test" in GB / T50080-2012 "Standard for performance test methods of ordinary concrete mixtures", the setting time of the concrete of Examples 1-9 and Comparative Examples 1-4 was tested, and the initial setting time and final setting time were recorded.

[0105] 2. Compressive strength: According to "5. Compressive strength test" in GB / T50081-2019 "Standard for Test Methods for Physical and Mechanical Properties of Concrete", the concrete of Examples 1-9 and Comparative Examples 1-4 were tested for 3d and 28d compressive strength, and the compressive strength was recorded.

[0106] The above test data are detailed in Table 2.

[0107] Table 2

[0108]

[0109]

[0110] According to the comparison of the test data of Example 1 and Comparative Examples 1-3 in Table 2, it can be seen that the concrete of Example 1 is higher than that of Comparative Examples 1-3 at 3d and 28d, especially the late strength, indicating that the late strength of the concrete provided by the present application has been effectively improved. The setting time of Example 1 is also shorter than that of Comparative Examples 1-3, and has a good quick-setting effect. It shows that with the combination of warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose, and a specific quick-setting agent, a specific spatial network structure can be quickly and smoothly formed, thereby achieving quick setting and high strength.

[0111] Combined with the test data of Comparative Example 4, it can be seen that the concrete of Comparative Example 4 has higher compressive strength than those of Comparative Examples 1-3, and shorter coagulation time than those of Comparative Examples 1-3. However, the compressive strength and coagulation effect of the concrete of Comparative Example 4 are still not as high as those of Example 1. This shows that not only the combination of warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose, and a specific accelerating agent should be limited, but also the dosage and matching relationship of the three should be further limited, otherwise it is impossible to obtain fast-setting and high-strength concrete.

[0112] Combining the test data of Examples 1, 7-8 and 9, it can be seen that although Example 9 also has good compressive strength and faster solidification effect, Example 1 is still better than Example 9. It shows that further limiting the ratio between the warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose and the specific accelerating agent at a specific dosage can have a more sufficient coordination, thereby obtaining concrete with more significant performance.

[0113] According to the comparison of the test data of Examples 1-3 with Examples 4 and 5, it can be seen that the concrete of Examples 1-3 has higher compressive strength and faster setting effect than that of Examples 4 and 5. It is shown that further limiting the amount and proportion of the raw materials in the accelerating agent is conducive to a better matching effect with the warm wheel glue and sodium carboxymethyl hydroxyethyl cellulose in the concrete system, thereby further improving the performance of the concrete.

[0114] According to the comparison of the test data of Example 1 and Example 6, after changing the sintering temperature for preparing the accelerating setting agent, the structure of the accelerating setting agent prepared may change, thereby affecting its effect in concrete.

[0115] This specific embodiment is merely an explanation of the present application and is not a limitation of the present application. After reading this specification, those skilled in the art may make modifications to the present embodiment without any creative contribution as needed. However, as long as it is within the scope of the claims of the present application, it shall be protected by the patent law.

Claims

1. A concrete for grouting bottom sealing in a foundation pit with strong flow conditions in a broken zone, characterized in that: According to the mass percentage, the raw materials are: 360-390 parts of Portland cement, 40-80 parts of admixture, 1000-1200 parts of coarse aggregate, 600-750 parts of fine aggregate, 3-7 parts of water reducer, 145-160 parts of water, 0.5-3 parts of Wenlun glue, 1.5-3.5 parts of sodium carboxymethyl hydroxyethyl cellulose, 2-6 parts of accelerator; The raw materials of the quick-setting agent are: 30-50 parts of aluminum sulfate, 30-60 parts of polyaluminum sulfate, 80-150 parts of calcium carbonate, 0.1-0.5 parts of activator, and 1-5 parts of water reducer according to the mass proportion; The mass ratio of aluminum sulfate, polyaluminum sulfate and calcium carbonate is 1: (1.0-1.5): (2-3), with the mass of aluminum sulfate as the basis; The preparation method of the accelerating setting agent comprises the following steps: mixing aluminum sulfate, polyaluminum sulfate and calcium carbonate, sintering at 800-950° C. for 30-60 minutes, and then mixing with an activator and a water reducing agent, grinding, and obtaining the accelerating setting agent.

2. The concrete for grouting bottom sealing in strong flow conditions in a broken zone foundation pit according to claim 1 is characterized in that: The mass ratio of the warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose and accelerating agent is (1.5-2.5): (1.8-2.3): (3-5).

3. The concrete for grouting bottom sealing in strong flow conditions in a broken zone foundation pit according to claim 1 is characterized in that: The admixture includes a mixture of one or more of fly ash, silica fume, limestone and slag powder.

4. The concrete for grouting bottom sealing in a broken zone foundation pit under strong flow conditions according to any one of claims 1 to 3, characterized in that: The method for preparing the concrete comprises the following steps: Mixing silicate cement and admixtures, and then adding water and mixing until uniform to obtain cement slurry; Then, the coarse aggregate and the fine aggregate are mixed evenly to obtain the material to be used; The material to be used is mixed with cement slurry, and then warm wheel glue, sodium carboxymethyl hydroxyethyl cellulose and accelerating setting agent are added and mixed together until uniform to obtain a finished product.

5. A construction method for grouting bottom sealing in a foundation pit in a broken zone under strong flow conditions, characterized in that: The following steps are involved: Step 1): Excavation of foundation pit: excavate the foundation pit to the specified depth; Step 2): Support pile construction: Support piles are set around the foundation pit, and the area surrounded by the support piles is the working area; Step 3): Bottom sealing: piles are set at the bottom of the working area corresponding to the foundation pit, and jet grouting piles are formed by jet grouting. The jet grouting piles form a substantially closely packed hexagonal or plum blossom array that interlocks with each other, and a sealing bottom layer composed of jet grouting piles is formed at the bottom of the working area corresponding to the foundation pit; During rotary grouting, the concrete for grouting bottom sealing under strong flow conditions in the foundation pit of the broken zone as described in any one of claims 1 to 4 is used.

6. The construction method for grouting bottom sealing in a broken zone foundation pit under strong flow conditions according to claim 5 is characterized in that: The outer side edge of the sealing layer abuts against the inner side surface of the supporting pile.

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