A nondestructive testing and evaluation method for the effect of grouting reinforcement of earthen ruins

Abstract

The present invention belongs to the technical field of evaluation of fissure grouting reinforcement effect of earthen sites, and is mainly used for quantitative evaluation of grouting fullness, surface shrinkage cracking, and sealing compatibility of fissure grouting reinforcement of earthen sites, including fissure grouting reinforcement model, non-destructive testing evaluation index and system of grouting reinforcement effect, specifically involving ultrasonic velocity detection, thermal infrared detection, and color difference detection; the grouting fullness detection adopts the wave velocity ratio index method of the fissure grouting reinforcement model and the rammed earth test block without cracks; the surface shrinkage cracking detection adopts the surface shrinkage cracking and crack width ratio method; the sealing compatibility detection adopts the color difference value method of the grouting sealing part of the fissure grouting reinforcement model and the rammed earth test block without cracks. The present invention is a non-destructive testing evaluation method of fissure grouting reinforcement effect of earthen sites with strong applicability, quantification, rich working conditions, wide age range, low disturbance and risk.

Description

Technical Field

[0001] The invention belongs to the technical field of evaluation of fissure grouting reinforcement effect of earthen ruins, and specifically relates to a non-destructive detection evaluation method for fissure grouting reinforcement effect of earthen ruins, which is mainly used for quantitatively evaluating grouting fullness, surface shrinkage cracking, and sealing compatibility of fissure grouting reinforcement of earthen ruins. Background Art

[0002] Earthen sites are the remains of earthen buildings left over from various activities such as production, culture, religion and military defense in human history. They are a combination of ancient geotechnical construction technology and historical culture. Earthen sites are mainly found in the arid and semi-arid areas of northwest my country. However, due to the influence of construction technology and long-term natural factors, various forms of cracks are formed on the earthen sites. The development and growth of cracks not only affect the overall stability of earthen sites, but also serve as a channel for other external forces to accelerate the weathering of earthen sites. The crack grouting reinforcement technology for earthen sites can effectively prevent the further development of cracks by filling them with slurry to prevent rainwater from infiltrating through the cracks, thereby improving the integrity and durability of the site.

[0003] During the grouting reinforcement process of earthen sites, irregular crack development, large shrinkage of grouting materials, and non-standard grouting process lead to low effective bonding of grouting, incomplete grouting inside cracks, and rapid penetration of water in the grouting, resulting in large shrinkage and cracking on the grouting surface, which cause risk uncertainty and potential hidden dangers after the reinforcement of earthen sites. According to the principle of "not changing the original state" of cultural relics protection, appropriate surface treatment should be done after grouting reinforcement to make it coordinated with the site body, which puts higher requirements on the sealing compatibility of grouting reinforcement of earthen sites. In view of the low strength, high value and indestructibility of earthen sites, the evaluation methods of grouting effect with certain destructiveness in geotechnical engineering such as core sampling test, water pressure test and load test are not applicable to earthen sites with cultural relics. Although non-destructive testing methods have been applied to the field of grouting reinforcement of earthen sites, there is a lack of quantitative evaluation indicators and a comprehensive detection and evaluation system, and the reinforcement effect is mainly based on qualitative judgment based on experience. Taking into full consideration the dual properties of earthen site soil and cultural relics, it is an inevitable trend for the scientific and standardized reinforcement technology of earthen site to establish a fast, high-precision and reliable non-destructive detection and evaluation method for the effect of fissure grouting reinforcement.

[0004] Therefore, we propose a nondestructive testing and evaluation method for the crack grouting reinforcement effect of earthen sites. Summary of the invention

[0005] The purpose of the present invention is to propose a non-destructive detection and evaluation method for the grouting reinforcement effect of earthen sites. In view of the current situation that the grouting reinforcement effect of existing earthen sites tends to be qualitatively evaluated, a non-destructive detection and evaluation system with grouting fullness, surface shrinkage cracking, and sealing compatibility as key indicators is established on the basis of fully considering the cultural relics attributes of earthen sites, so as to solve the problems of applicability and limitations of the existing grouting reinforcement effect evaluation method in earthen sites.

[0006] To achieve the above purpose, the specific technical solution adopted by the present invention is as follows:

[0007] A non-destructive testing and evaluation method for the fissure grouting reinforcement effect of earthen ruins, including the production of a fissure grouting reinforcement model and the establishment of a non-destructive testing evaluation index and system for the grouting reinforcement effect;

[0008] The fissure grouting reinforcement model is used to simulate the fissure grouting reinforcement of earthen ruins;

[0009] The non-destructive testing evaluation index and system for the grouting reinforcement effect are used to evaluate the grouting fullness, surface shrinkage cracking, and sealing compatibility after reinforcement.

[0010] Furthermore, the crack grouting reinforcement model includes a rammed earth specimen, a grouting slurry, and a transparent acrylic plate; the transparent acrylic plate is formed into a mold with four sides and a bottom closed by splicing or bonding; the rammed earth specimens are placed on both sides of the transparent acrylic plate mold, and cracks are reserved between the rammed earth specimens; the grouting slurry is poured into the prefabricated cracks of the rammed earth specimens; and the transparent acrylic plate is removed after the slurry hardens.

[0011] Furthermore, the non-destructive testing evaluation index and system of the grouting reinforcement effect include ultrasonic velocity testing, thermal infrared testing, and color difference testing;

[0012] Among them, ultrasonic velocity detection is used to detect the fullness of grouting, thermal infrared detection is used to detect surface shrinkage cracking, and color difference detection is used to detect the compatibility of sealing and protection;

[0013] The grouting fullness test adopts the wave velocity ratio index method of the crack grouting reinforcement model and the crack-free rammed earth specimen; the surface shrinkage cracking test adopts the surface shrinkage cracking and crack width ratio method; the sealing compatibility test adopts the color difference value method of the grouting sealing part of the crack grouting reinforcement model and the crack-free rammed earth specimen.

[0014] Furthermore, the wave velocity ratio index method of the fracture grouting reinforcement model and the non-crack rammed earth specimen is used: the effect of the grouting fullness is determined into five levels: "I (excellent), II (good), III (medium), IV (low), V (poor)", with a wave velocity ratio index of >0.90 for level I, a wave velocity ratio index of 0.90-0.75 for level II, a wave velocity ratio index of 0.74-0.50 for level III, a wave velocity ratio index of 0.49-0.25 for level IV, and a wave velocity ratio index of <0.25 for level V.

[0015] Furthermore, the wave velocity ratio index can be calculated according to formula (1):

[0016]

[0017] In formula (1): VRI is the wave velocity ratio index;

[0018] v1 is the wave velocity value of the fracture grouting reinforcement model;

[0019] v2 is the wave velocity value of the rammed earth specimen without cracks.

[0020] Furthermore, the surface shrinkage cracking and crack width ratio method: the effect of surface shrinkage cracking is determined into three levels of "I (small), II (medium), III (large)", for small cracks (<5cm), the width ratio <15% is level I, the width ratio 15-18% is level II, and the width ratio >18% is level III; for large cracks (≥5cm), the width ratio <10% is level I, the width ratio 10-13% is level II, and the width ratio >13% is level III.

[0021] Furthermore, the width ratio can be calculated according to formula (2):

[0022]

[0023] In formula (2): r is the width ratio;

[0024] d is the surface shrinkage crack width;

[0025] D is the crack width.

[0026] Furthermore, the surface shrinkage crack width can be calculated based on the ratio of the number of temperature data points at the cracks on the fracture grouting reinforcement model measurement line to the total number of temperature data points on the measurement line:

[0027]

[0028] In formula (3): d is the surface shrinkage crack width;

[0029] l is the length of the measuring line;

[0030] n1 is the number of temperature data points at the surface shrinkage cracking;

[0031] n2 is the total number of temperature data points on the measuring line.

[0032] Furthermore, the color difference method of the grouting sealing part of the crack grouting reinforcement model and the rammed earth test block without cracks: the effect of the sealing compatibility is determined as "I (excellent), II (good), III (medium), IV (low), V (poor)" 5 levels, the color difference value of 0-0.5 is level I, the color difference value of 0.6-1.5 is level II, the color difference value of 1.6-3 is level III, the color difference value of 3.1-6 is level IV, and the color difference value >6 is level V.

[0033] Furthermore, the color difference value can be calculated according to formula (4):

[0034]

[0035] Where: ΔE is the color difference value;

[0036] L is the brightness value of the grouting seal;

[0037] a is the red-green value of the grouting seal;

[0038] b is the yellow-blue value of the grouting seal;

[0039] L * is the brightness value of the rammed earth test block;

[0040] a * is the red and green value of the rammed earth test block;

[0041] b * It is the yellow-blue value of the rammed earth specimen.

[0042] In summary, due to the adoption of the above technical solution, the beneficial technical effects of the invention are:

[0043] (1) This method has strong applicability in effect evaluation and truly reflects the technical characteristics of grouting reinforcement of earthen sites. It comprehensively tests grouting fullness, surface shrinkage cracking, and sealing compatibility, making the evaluation results more comprehensive and objective.

[0044] (2) This method quantifies the evaluation indicators and determines the corresponding thresholds, constructs a technical system for evaluating the grouting reinforcement effect of earthen sites, and fundamentally changes the shortcomings of the existing qualitative evaluation.

[0045] (3) The crack grouting reinforcement model of this method is presented in an open form, and the use of a transparent acrylic plate mold can achieve visibility of the grouting reinforcement and curing process.

[0046] (4) This method has a wide range of test conditions. The fissure grouting reinforcement model can be adjusted according to the test requirements. It can build rammed earth test blocks with different layer thicknesses and densities to meet the test requirements of earthen sites of different shapes; it can build rammed earth test blocks with different shapes and surface morphologies to meet the test requirements of fissures with different characteristics; it can pour grouting slurries with different materials, proportions and water-cement ratios to meet the test requirements of different grouting slurry selections; it can choose from a variety of grouting methods such as gravity grouting and pressure grouting to meet the test requirements of different grouting process selections.

[0047] (5) This method has a wide range of test ages. From the initial stage of grouting to the long-term curing process, ultrasonic velocity detection, thermal infrared detection, and color difference detection can all achieve continuous data collection, thus realizing the detection and evaluation of the grouting reinforcement process.

[0048] (6) The detection content of this method is simple and easy, with strong adaptability, low requirements for application scenarios and technologies, and can achieve the goal of non-destructive, rapid, high-precision and reliable effect evaluation.

[0049] (7) This method uses non-destructive testing to evaluate the reinforcement effect, which has low disturbance and risk to the earthen ruins. It is easy to transplant it to the on-site testing of grouting reinforcement projects of earthen ruins and is easy to transform the results in the later stage. BRIEF DESCRIPTION OF THE DRAWINGS

[0050] Figure 1 Flow chart of nondestructive testing and evaluation method for crack grouting reinforcement effect of earthen ruins

[0051] Figure 2 Schematic diagram of the fracture grouting reinforcement model

[0052] Figure 3 Ultrasonic velocity detection diagram

[0053] Figure 4 Thermal infrared detection schematic diagram

[0054] Figure 5 Schematic diagram of grouting reinforcement model for gully-type fissures DETAILED DESCRIPTION

[0055] In order to make the purpose, technical solution and advantages of the invention more clear, the invention is further described in detail below in conjunction with the embodiments. It should be understood that the specific embodiments described here are only used to explain the invention and are not used to limit the invention.

[0056] (1) Crack grouting reinforcement model. A detailed on-site investigation of the shape and crack characteristics of the pre-grouting reinforced earth site was conducted, which was used as the basis for making the rammed earth test block 1. The collapsed site soil prepared to the optimal moisture content was layered and rammed according to the original construction process of the earth site. The thickness and dry density of the rammed layer should be consistent with those of the earth site; the surface morphology of the rammed earth test block 1 should be consistent with the cracks of the earth site. After the rammed earth test block 1 was made, it was naturally air-dried in the laboratory until the quality was stable. The transparent acrylic plate 3 was spliced / bonded to form a mold with closed sides and bottom. The mold should be slightly higher than the rammed earth test block 1 to prevent the grouting slurry 2 from flowing out. Before grouting, the prepared rammed earth test block 1 was placed on both sides of the grouting mold. The rammed earth test block 1 was close to the inner wall of the mold, and a crack was reserved in the middle. The width of the prefabricated crack should be consistent with the cracks of the earth site. According to the requirements of the grouting material, the grouting slurry 2 with the same material, proportion and water-cement ratio as the grouting reinforcement project was prepared. According to the requirements of the grouting process, select the pressure grouting or gravity grouting that is consistent with the grouting reinforcement project, and pour it into the prefabricated cracks of the rammed earth test block 1 from bottom to top through the catheter until the top of the slurry is flush with the rammed earth test block 1. After the slurry is initially hardened, the mold is removed and placed in an environmental box for curing. The curing temperature and humidity settings should be consistent with the on-site environment of the earth site. From the initial grouting to the long-term curing process, the fracture grouting reinforcement model can complete ultrasonic velocity detection, thermal infrared detection, and color difference detection at different ages to achieve detection and evaluation of the grouting reinforcement process.

[0057] (2) Ultrasonic velocity detection. The propagation velocity of ultrasound decreases as the proportion of cracks, holes and defects in the medium increases. Based on this principle, the grouting fullness can be quantitatively evaluated. The transmitting and receiving probes 4 of the ultrasonic velocity detection are placed on both sides of the outer surface of the rammed earth specimen 1. The propagation path of the ultrasound should pass through the grouting cracks of the model, and the wave velocity ratio index of the crack grouting reinforcement model and the crack-free rammed earth specimen is calculated. The effect of the grouting fullness is determined as "I (excellent), II (good), III (medium), IV (low), V (poor)". The wave velocity ratio index > 0.90 is level I, the wave velocity ratio index 0.90-0.75 is level II, the wave velocity ratio index 0.74-0.50 is level III, the wave velocity ratio index 0.49-0.25 is level IV, and the wave velocity ratio index < 0.25 is level V. The wave velocity ratio index can be calculated according to the following formula:

[0058]

[0059] Where:

[0060] VRI – Velocity Ratio Index;

[0061] v1——wave velocity value of the fracture grouting reinforcement model;

[0062] v2——wave velocity value of the rammed earth specimen without cracks.

[0063] (3) Thermal infrared detection. When defects occur on the surface of a structure, the local thermal conductivity will change. There is a significant temperature difference between the surface shrinkage crack 5 and the surrounding soil. Based on this principle, the surface shrinkage crack can be quantitatively evaluated. In the infrared photo of the crack grouting reinforcement model, a measuring line 6 is arranged perpendicular to the grouting crack direction. The temperature data on the measuring line 6 is extracted by mathematical software to determine the ratio of the number of temperature data points at the surface shrinkage crack 5 on the measuring line 6 of the crack grouting reinforcement model to the total number of temperature data points on the measuring line 6. The width ratio of the surface shrinkage crack 5 to the crack is further calculated. The effect of the surface shrinkage crack is determined into three levels: "I (small), II (medium), and III (large)". For small cracks (<5cm), the width ratio <15% is level I, the width ratio 15-18% is level II, and the width ratio >18% is level III; for large cracks (≥5cm), the width ratio <10% is level I, the width ratio 10-13% is level II, and the width ratio >13% is level III. The surface shrinkage crack width and width ratio can be calculated according to the following formula:

[0064]

[0065]

[0066] Where:

[0067] r – width ratio;

[0068] d——surface shrinkage crack width;

[0069] D – crack width;

[0070] l——measurement line length;

[0071] n1——Number of temperature data points at the surface shrinkage cracking;

[0072] n2——Total number of temperature data points of the measuring line.

[0073] (4) Color difference detection. Color difference detection obtains quantitative color data and clarifies the degree of coordination between the grouting reinforcement cracks and the surrounding soil. Based on this principle, the sealing compatibility can be quantitatively evaluated. The average values ​​of multi-point brightness, red-green, yellow-blue are detected on the grouting sealing part of the crack grouting reinforcement model and the rammed earth test block without cracks, and the color difference value between the grouting sealing part of the crack grouting reinforcement model and the rammed earth test block without cracks is calculated. The effect of sealing compatibility is determined as "I (excellent), II (good), III (medium), IV (low), V (poor)" 5 levels, color difference value 0-0.5 is level I, color difference value 0.6-1.5 is level II, color difference value 1.6-3 is level III, color difference value 3.1-6 is level IV, color difference value >6 is level V. The color difference value can be calculated according to the following formula:

[0074]

[0075] Where:

[0076] ΔE——color difference value;

[0077] L——brightness value of grouting sealing area;

[0078] a——Red and green value of grouting sealing point;

[0079] b——yellow-blue value of grouting sealing area;

[0080] L * ——Brightness value of rammed earth test block;

[0081] a * ——Red and green values ​​of rammed earth test blocks;

[0082] b * ——Yellow-blue value of rammed earth test block.

[0083] Specifically, this embodiment conducts a comprehensive analysis based on a detection experiment of the effect of grouting reinforcement of cracks in a certain earthen site.

[0084] (1) Crack grouting reinforcement model. The collapsed soil from a certain site was collected on site. After air drying, grinding and sieving, the wet soil was prepared with the optimal moisture content, and the rammed earth test blocks were prepared by tamping. The prepared rammed earth test blocks were naturally air dried until the quality was stable and placed in a transparent acrylic plate mold. The slurry was poured into the prefabricated cracks of the two rammed earth test blocks using a grouting device. After the slurry was initially hardened, the mold was removed and the test blocks were placed in an environmental box for curing. The curing temperature and humidity were set according to the temperature and humidity monitoring results of the earth site. After a certain curing age, ultrasonic velocity detection, thermal infrared detection and color difference detection were carried out respectively. In order to explore the influence of soil density, slurry ratio, crack width and crack morphology on the grouting reinforcement effect, the dry density of the rammed earth test blocks was set to 1.70g / cm 3 , 1.75g / cm 3 The specifications of the rammed earth test blocks are cube and prism (cube with chamfered edges). Two cube rammed earth test blocks are prefabricated with vertical cracks, and two prism rammed earth test blocks are prefabricated with gully ("V") cracks. The width of the cracks reserved in the transparent acrylic plate mold is 3 cm and 5 cm. The slurry is made of hydraulic lime mixed with ruins soil, with a ratio of 1:10 and 1:25. The model number and parameters of the crack grouting reinforcement are shown in Table 1.

[0085] Table 1 Parameters of the fracture grouting reinforcement model

[0086]

[0087] (2) Ultrasonic velocity detection. The detection uses a certain type of ultrasonic parameter tester. The transmitting and receiving probes are placed on both sides of the outer surface of the rammed earth test block. The ultrasonic propagation path passes through the grouting cracks of the model. After multiple tests, the average wave velocity is obtained. 1.70g / cm 3The average wave velocity of the crack-free rammed earth specimen with dry density is 1225.8m / s, 1.75g / cm 3 The average wave velocity of the dry density crack-free rammed earth specimen is 1282.5 m / s. The wave velocity ratio index (VRI) of the crack grouting reinforcement model L1-L5 is greater than 0.90, and the grouting fullness effect is evaluated as I (excellent).

[0088] Table 2 Evaluation of grouting fullness of fracture grouting reinforcement model

[0089] parameter L1 L2 L3 L4 L5 <![CDATA[v1(m / s)]]> 1440.8 1322.3 1278.1 1315.1 1331.2 VRI 1.06 1.04 1.00 1.01 1.02

[0090] (3) Thermal infrared detection. A certain type of infrared thermal imager is used to perform thermal infrared photography on the grouting surface of the crack grouting reinforcement model. A measuring line is arranged in the thermal infrared photo, and the temperature data on the measuring line is extracted. The surface shrinkage cracks are discontinuous with the heat conduction between the rammed earth and the slurry, and have obvious temperature value differences. The width ratio of models L1, L2, and L5 is less than 15%, and the effect of surface shrinkage cracks is evaluated as level I (small); the width ratio of model L3 (≥5cm) is greater than 13%, and the effect of surface shrinkage cracks is evaluated as level III (large); the width ratio of model L4 is 15-18%, and the effect of surface shrinkage cracks is evaluated as level II (medium).

[0091] Table 3 Evaluation of surface shrinkage cracking of fracture grouting reinforcement model

[0092] parameter L1 L2 L3 L4 L5 L(cm) 14.65 16.22 17.07 15.36 9.06 <![CDATA[n1]]> 15 14 23 15 22 <![CDATA[n2]]> 511 516 595 512 511 d(cm) 0.43 0.44 0.66 0.45 0.39 r(％) 14.42 14.58 13.14 15.15 13.10

[0093] (4) Color difference detection. A certain type of colorimeter was used for detection. The brightness value, red-green value, and yellow-blue value of multiple points of the grouting reinforcement crack sealing and rammed earth test blocks were collected, and the average value of each parameter was calculated. The color difference values ​​of models L1 and L2 were 1.6-3, and the effect of sealing compatibility was evaluated as III (medium); the color difference values ​​of models L3 and L4 were greater than 6, and the effect of sealing compatibility was evaluated as V (poor); the color difference value of model L6 was 3.1-6, and the effect of sealing compatibility was evaluated as IV (low).

[0094] Table 4 Evaluation of sealing compatibility of fracture grouting reinforcement model

[0095] parameter L1 L2 L3 L4 L5 L-L* 2.11 2.62 6.00 5.54 3.56 a-a* 0.77 0.37 0.13 1.80 0.56 b-b* 0.89 0.09 1.05 3.71 0.46 ΔE 2.42 2.65 6.09 6.91 3.63

[0096] (5) Evaluation of reinforcement effect. In this embodiment, the effect of grouting fullness is good; for large cracks (≥5cm) and a slurry ratio of 1:25, the effect of surface shrinkage cracking is average; the effect of sealing compatibility is poor overall. Therefore, the crack grouting reinforcement of this embodiment should adopt a slurry ratio of 1:10, and is suitable for grouting of small cracks (<5cm). If it is used in the on-site reinforcement project of earthen ruins, the color difference value should be further reduced.

[0097] Table 5 Evaluation of crack grouting reinforcement effect

[0098] Evaluation indicators L1 L2 L3 L4 L5 Grouting fullness I I I I I Surface shrinkage cracking I I III II I Sealing compatibility III III V V IV

[0099] The above description is a preferred embodiment of the invention and is not intended to limit the invention. Any modifications, equivalent substitutions and improvements made within the spirit and principle of the invention should be included in the protection scope of the invention.

Claims

1. A non-destructive testing and evaluation method for the effect of grouting reinforcement of earthen ruins, characterized in that: Including the production of fracture grouting reinforcement model, and the establishment of non-destructive testing evaluation indicators and systems for grouting reinforcement effects; The fissure grouting reinforcement model is used to simulate the fissure grouting reinforcement of earthen ruins; The non-destructive testing evaluation index and system of the grouting reinforcement effect are used to evaluate the grouting fullness, surface shrinkage cracking, and sealing compatibility after reinforcement; Among them, ultrasonic velocity detection is used to detect the fullness of grouting, thermal infrared detection is used to detect surface shrinkage cracking, and color difference detection is used to detect the compatibility of sealing and protection; The grouting fullness test adopts the wave velocity ratio index method of the crack grouting reinforcement model and the crack-free rammed earth test block; the surface shrinkage cracking test adopts the surface shrinkage cracking and crack width ratio method; the sealing compatibility test adopts the color difference value method of the crack grouting reinforcement model grouting sealing part and the crack-free rammed earth test block; The width ratio can be calculated according to formula (2): In formula (2): r is the width ratio; d is the surface shrinkage crack width; D is the crack width; The wave velocity ratio index method of the fissure grouting reinforcement model and the non-fissure rammed earth test block: the effect of the grouting fullness is determined as "I (excellent), II (good), III (medium), IV (low), V (poor)" 5 levels, wave velocity ratio index> 0.90 is level I, wave velocity ratio index 0.90-0.75 is level II, wave velocity ratio index 0.74-0.50 is level III, wave velocity ratio index 0.49-0.25 is level IV, wave velocity ratio index <0.25 is level V; The wave velocity ratio index can be calculated according to formula (1): In formula (1): VRI is the wave velocity ratio index; v1 is the wave velocity value of the fracture grouting reinforcement model; v2 is the wave velocity value of the rammed earth specimen without cracks; The fissure grouting reinforcement model comprises a rammed earth test block, grouting slurry, and a transparent acrylic plate; the transparent acrylic plate is spliced ​​or bonded to form a mold with four sides and a bottom closed; the rammed earth test blocks are placed on both sides of the transparent acrylic plate mold, and fissures are reserved between the rammed earth test blocks; the grouting slurry is poured into the prefabricated fissures of the rammed earth test blocks; and the transparent acrylic plate is removed after the slurry hardens; The surface shrinkage cracking and crack width ratio method: the effect of surface shrinkage cracking is determined into three levels of "I (small), II (medium), III (large)", for small cracks (<5cm), width ratio <15% is level I, width ratio 15-18% is level II, width ratio >18% is level III; for large cracks (≥5cm), width ratio <10% is level I, width ratio 10-13% is level II, width ratio >13% is level III; The surface shrinkage crack width can be calculated based on the ratio of the number of temperature data points at the cracks on the fracture grouting reinforcement model measurement line to the total number of temperature data points on the measurement line: In formula (3): d is the surface shrinkage crack width; l is the length of the measuring line; n1 is the number of temperature data points at the surface shrinkage cracking; n2 is the total number of temperature data points on the measuring line; The color difference method of the grouting sealing part of the crack grouting reinforcement model and the rammed earth test block without cracks: the effect of sealing compatibility is determined as "I (excellent), II (good), III (medium), IV (low), V (poor)" 5 levels, the color difference value 0-0.5 is level I, the color difference value 0.6-1.5 is level II, the color difference value 1.6-3 is level III, the color difference value 3.1-6 is level IV, and the color difference value>6 is level V; The color difference value can be calculated according to formula (4): In formula (4): ΔE is the color difference value; L is the brightness value of the grouting seal; a is the red-green value of the grouting seal; b is the yellow-blue value of the grouting seal; L* is the brightness value of the rammed earth specimen; a* is the red-green value of the rammed earth test block; b* is the yellow-blue value of the rammed earth specimen.

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