Cement mixing pile overall stability evaluation method, system, equipment and medium

Abstract

The invention discloses a cement mixing pile overall stability evaluation method, system and equipment and a medium. The method comprises the steps that S1, soil layer information corresponding to different depth sections of a to-be-evaluated foundation in the position where each mixing pile is located is obtained; s2, the most dangerous sliding surface and the sliding force of the most dangerous sliding surface are determined in the foundation to be evaluated, the pile section, where the most dangerous sliding surface passes, of the stirring pile is marked as a target pile section, and the pile section of the stirring pile is divided with a depth section as a node; s3, construction parameters of each target pile section are obtained; s3, an age is preset, the soil layer information and the construction parameters corresponding to all the target pile sections and the set age are input into the pile forming quality prediction model, and pile forming strength information of all the target pile sections is obtained; s5, based on the pile forming strength information corresponding to each target pile section, the anti-sliding force is calculated; and S6, the overall stability of the foundation to be evaluated is determined according to the ratio of the anti-sliding force to the sliding force. The actual soil layer distribution condition and the pile forming quality are fully considered, and the reliability of overall stability evaluation of the foundation is improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of foundation reinforcement, and particularly relates to a cement mixing pile overall stability evaluation method, system, device and medium. BACKGROUND

[0002] In the design stage, when checking the overall stability of the cement mixing pile composite foundation, the ratio between the anti-sliding force and the sliding force of the most dangerous sliding surface of the foundation is mainly checked to see whether it exceeds a certain safety factor as the main standard. Since the design stage can only be based on extremely limited survey holes, it is assumed that the soil layer distribution of the entire foundation is consistent with the stratum distribution determined by the survey holes, so after the mixing pile reinforced foundation, the quality of the formed pile is often uneven, and the quality of the formed pile is usually evaluated by two detection methods of drilling core or load plate test. However, drilling core can only evaluate the quality of a single pile, and load plate test can cover multiple mixing piles and reflect the overall bearing capacity of the multiple mixing piles and the soil around the piles, but the coverage range is still limited for the entire foundation. Therefore, the existing detection method cannot evaluate the quality of each mixing pile, but only assumes that the quality of the undetected pile is consistent with that of the detected pile, and evaluates the overall quality of the composite foundation by statistical analysis using the average strength and standard, without considering the actual soil layer distribution and the actual pile quality, so the reliability of the overall stability evaluation of the foundation is low. SUMMARY

[0003] The purpose of the present application is to provide a cement mixing pile overall stability evaluation method, system, device and medium, which fully considers the actual soil layer distribution and the pile quality, and improves the reliability of the overall stability evaluation of the foundation.

[0004] The present application is realized by the following technical solutions:

[0005] A cement mixing pile overall stability evaluation method, comprising the following steps:

[0006] S1, acquiring soil layer information corresponding to different depth sections of each mixing pile in the foundation to be evaluated, the soil layer information including a soil layer type and soil layer parameters corresponding to the soil layer type;

[0007] S2, determining a most dangerous sliding surface and a sliding force of the most dangerous sliding surface in the foundation to be evaluated, and recording the pile section of the mixing pile passed by the most dangerous sliding surface as a target pile section, wherein the mixing pile is divided into different pile sections according to different depth sections;

[0008] S3, acquiring construction parameters of each target pile section, the construction parameters including a cement content, a water content, a mixing and soil cutting frequency per meter after jet grouting, and a mixing and soil cutting frequency per meter before jet grouting;

[0009] S4, presetting an age, for each target pile section, inputting the soil layer information corresponding to the target pile section, the construction parameter and the preset age into the constructed pile quality prediction model to obtain the pile strength information of each target pile section;

[0010] S5, calculating the anti-sliding force based on the pile strength information corresponding to each target pile section;

[0011] S6, determining the overall stability of the foundation to be evaluated according to the ratio of the anti-sliding force to the sliding force.

[0012] Further, the pile strength information includes a plurality of pile strength ranges and the probability of each pile strength range;

[0013] Based on the pile strength information corresponding to each target depth section, the step of calculating the anti-sliding force comprises:

[0014] S51, calculating the strength expectation value of the target pile section by the following formula:

[0015]

[0016] In the formula, E q is the strength expectation value of the target pile section, m is the number of pile strength ranges, a i is the characteristic strength of the i-th pile strength range, q i下限 is the lower limit boundary value of the i-th pile strength range, q i上限 is the upper limit boundary value of the i-th pile strength range, q m下限 is the lower limit boundary value of the m-th pile strength range, P i is the probability of the i-th pile strength range;

[0017] S52, calculating the anti-sliding force by the following formula:

[0018]

[0019] In the formula, F 抗滑 is the anti-sliding force, n 桩 is the number of mixing piles in the section, A is the cross-sectional area of the mixing pile, E iq is the strength expectation value of the i-th target depth section.

[0020] Further, the step of obtaining the soil layer information corresponding to each depth section of the foundation to be evaluated at the position of each mixing pile comprises:

[0021] S11, determining a plurality of soil layer types contained in the foundation to be evaluated, and obtaining the soil layer parameters of each soil layer type;

[0022] S12, obtaining the monitoring information collected every preset collection time in the construction process of the mixing pile, the monitoring information including the penetration depth and the measured end resistance;

[0023] S13, calculating the calculated end resistance of each depth section in the construction process of the under-penetration pile based on the soil layer information corresponding to the under-penetration depth;

[0024] S14, judging whether the difference between the measured end resistance corresponding to the under-penetration depth and the calculated end resistance of the corresponding depth section is within a preset error interval;

[0025] S15, if yes, taking the soil layer type corresponding to the under-penetration depth as the soil layer type of the corresponding depth section to obtain the soil layer information corresponding to different depth sections;

[0026] S16, if no, changing the soil layer type corresponding to the under-penetration depth and repeating steps S13 and S14.

[0027] Further, the soil layer parameters include cohesion, friction angle, unit weight and lateral pressure coefficient;

[0028] The step of calculating the calculated end resistance of each depth section in the construction process of the under-penetration pile based on the soil layer information corresponding to the under-penetration depth includes:

[0029] The calculated end resistance of each depth section in the construction process of the under-penetration pile is calculated by the following formula:

[0030] F 推算端阻力 =σ1S 竖 (4);

[0031] S 竖 =πd 2 +n 叶 B·l·cosθ (5);

[0032]

[0033] σ3=σ zi k si (7);

[0034]

[0035] In the formula, F 推算端阻力 is the calculated end resistance, σ1 is the maximum principal stress when the soil body is in limit equilibrium, S 竖 is the vertical projection area of the mixing head of the mixing pile machine, n 叶 is the number of mixing blades of the mixing pile machine, σ3 is the minimum principal stress when the soil body is in limit equilibrium, d is the diameter of the drill rod of the mixing pile machine, σ zi is the vertical effective stress of the overlying soil layer of the i-th layer, is the friction angle of the i-th layer of soil, c i is the cohesion of the i-th layer of soil, h si is the thickness of the i-th layer of soil, and k sicoefficient of lateral earth pressure of the i-th soil layer, γ si unit weight of the i-th soil layer, γ w unit weight of water, h w water depth.

[0036] Further, the step of obtaining the construction parameters of each target pile section comprises:

[0037] S31, obtaining construction collection data of the mixing pile recorded every interval time during the construction process, the construction collection data comprising recording time, real-time mortar injection flow, real-time water injection flow, real-time penetration speed, real-time lifting speed, real-time rotation speed and mixing head end elevation;

[0038] S32, based on the obtained construction collection data, the construction parameters of the target pile section are counted.

[0039] Further, in the step of obtaining the construction collection data of the mixing pile recorded every preset interval time during the construction process, the construction process of the mixing pile needs to meet a preset precondition, and the precondition comprises:

[0040] the mixing head of the mixing pile machine has an upper nozzle and a lower nozzle, and the upper nozzle is used to inject mortar or water when the mixing head is lifted, and the lower nozzle is used to inject mortar or water when the mixing head is penetrated;

[0041] from mortar injection to water injection or from water injection to mortar injection, the interval time does not exceed a preset conversion time;

[0042] Before construction by the mixing pile machine, the conveying pipeline of the mixing pile machine is in a full water state;

[0043] Based on the obtained construction collection data, the construction parameters of the target pile section are counted.

[0044] S321, from the obtained construction collection data, a construction collection data is sequentially selected in time order, the real-time mortar injection flow and the real-time water injection flow corresponding to the selected construction collection data are obtained according to a preset rule, so as to obtain the real-time mortar injection flow and the real-time water injection flow corresponding to each construction collection data;

[0045] S322, for each construction collection data, the real-time lifting speed and the mixing head end elevation in the construction collection data are used to determine the construction collection data corresponding to the depth section of the target pile section, and the target construction collection data is recorded;

[0046] S323, the cement parameter corresponding to the target pile section is calculated according to formula (9), and the water yield corresponding to the target pile section is calculated according to formula (10), wherein formula (9) is as follows:

[0047]

[0048] wherein a c is the cement content, ∑Q 浆 is the sum of real-time slurry discharge flow of the target construction collection data, ρ 水泥浆 is the cement slurry density, μ is the water-cement ratio, A is the treatment area of the mixing pile, and L is the length of the target pile section;

[0049] wherein formula (10) is as follows:

[0050]

[0051] wherein a w is the water content, ∑Q 水 is the sum of real-time water discharge flow of the target construction collection data, ρ 水 is the water density;

[0052] S324, the target construction collection data corresponding to the real-time slurry discharge flow greater than zero is classified into a group, and the initial slurry discharge time and the minimum slurry discharge elevation are determined according to the target construction collection data in the group;

[0053] S325, for each target construction collection data, if the record time in the target construction collection data is greater than the initial slurry discharge time, the target construction collection data is recorded as valid construction collection data, otherwise the target construction collection data is recorded as invalid construction collection data;

[0054] S326, for each target construction collection data, if the value of the drill bit end elevation minus the minimum slurry discharge elevation exceeds the interval between the upper and lower nozzles of the mixing head, the effective mixing number of blades n 有效 of the target construction collection data 层 =n 叶 ×n 有效 , otherwise the effective mixing number of blades n 层整 of the target construction collection data 喷口 =n 有效 ×n blades, n layers integral = Ht-Hslurry min L nozzle*n layers, wherein Ht is the drill bit end elevation, Hslurry min is the minimum slurry discharge elevation, L t is the interval between the upper and lower nozzles of the mixing head;

[0055] S327, the valid construction collection data is included in statistics, the effective mixing number N t of each valid construction collection data is calculated 有效 , and the effective mixing numbers of the valid construction collection data corresponding to the target pile section are summed to obtain the mixing and cutting soil number per meter after the target pile section is sprayed; t is the real-time rotating speed, T t is the preset interval time;

[0056] S328, invalid construction collection data is included in statistics, and the pre-stirring times N of each invalid construction collection data is calculated 预 = T t ·n t ·n 有效 The pre-stirring times of the invalid construction collection data corresponding to the target pile section are summed up, and the stirring and cutting soil times per meter before spraying of the target pile section are obtained.

[0057] The application further discloses a cement mixing pile overall stability evaluation system.

[0058] The first acquisition module is used to acquire soil layer information corresponding to different depth sections in each mixing pile of the foundation to be evaluated, and the soil layer information includes a soil layer type and soil layer parameters corresponding to the soil layer type.

[0059] The determination module is used to determine a most dangerous sliding surface and a sliding force of the most dangerous sliding surface in the foundation to be evaluated, and a pile section of a mixing pile passed by the most dangerous sliding surface is recorded as a target pile section, wherein the mixing pile is divided into different pile sections in different depth sections.

[0060] The second acquisition module is used to acquire construction parameters of each target pile section, and the construction parameters include a cement mixing amount, a water mixing amount, a stirring and cutting soil times per meter after spraying, and a stirring and cutting soil times per meter before spraying.

[0061] The input module is used to pre-set an age period, and for each target pile section, the soil layer information, the construction parameters and the set age period corresponding to the target pile section are input into the constructed pile forming quality prediction model to obtain pile forming strength information of each target pile section.

[0062] The calculation module is used to calculate a sliding resistance based on the pile forming strength information corresponding to each target pile section.

[0063] The evaluation module is used to determine the overall stability of the foundation to be evaluated according to a ratio of the sliding resistance to the sliding force.

[0064] The application further discloses an electronic device, and the electronic device comprises:

[0065] A processor;

[0066] A memory used for storing an executable computer program;

[0067] When the processor executes the computer program, the steps of the cement mixing pile overall stability evaluation method are realized.

[0068] The application further discloses a computer readable storage medium, and the computer readable storage medium stores a computer program, and when the computer program is executed by a processor, the steps of the cement mixing pile overall stability evaluation method are realized.

[0069] Compared with the prior art, the beneficial effects of the present application are: the true soil layer type and soil layer parameter of different depth sections of the mixing pile are obtained, the construction parameter of the target pile section through by the most dangerous sliding surface is determined, the soil layer parameter, construction parameter and age of the target pile section are used as input, the constructed pile quality prediction model is used to obtain the pile strength information of each target pile section, and the ratio of the anti-sliding force of the most dangerous sliding surface to the theoretical sliding force is calculated as the evaluation standard of the overall stability of the foundation to be evaluated; the present application can fully consider the actual soil layer condition and actual construction parameter, fully utilize the related data actually collected by the construction pile, avoid the survey cost of additional static sounding, dynamic sounding and drilling core, and greatly improve the reliability of the overall stability evaluation of the foundation to be evaluated. BRIEF DESCRIPTION OF DRAWINGS

[0070] Figure 1 The step flow chart of the cement mixing pile overall stability evaluation method of the present application;

[0071] Figure 2 The schematic diagram of determining the most dangerous sliding surface in the cement mixing pile overall stability evaluation method of the present application;

[0072] Figure 3 The module schematic diagram of the cement mixing pile overall stability evaluation system of the present application;

[0073] Figure 4 The hardware structure diagram of the electronic device of the present application. DETAILED DESCRIPTION

[0074] In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be described clearly and completely below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only some of the embodiments of the present application, rather than all the embodiments. The components of the embodiments of the present application described and shown in the drawings can be arranged and designed in various different configurations.

[0075] Therefore, the following detailed description of the embodiments of the present application provided in the drawings is not intended to limit the scope of the claimed present application, but only represents selected embodiments of the present application. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present application without creative labor are within the scope of protection of the present application.

[0076] It should be noted that: similar reference numerals and letters represent similar items in the following drawings, therefore, once an item is defined in one drawing, it does not need to be further defined and explained in the subsequent drawings. Meanwhile, in the description of the present application, the terms "first", "second" and the like are only used to distinguish description, and cannot be understood as indicating or implying relative importance.

[0077] It should be noted that the relational terms herein such as first and second and the like are used solely to distinguish one from another entity or action without necessarily requiring or implying that there is any such relationship or order between such entities or actions. Also, the terms "comprises", "comprising", or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but can also include other elements not expressly listed or inherent to such process, method, article, or apparatus. An element proceeded by "comprises... a" does not, without more constraints, exclude the existence of additional identical elements in the process, method, article, or apparatus that comprises the element.

[0078] In the description of the application, it should be noted that the terms "upper", "lower", "inner", "outer" and the like indicate the orientation or positional relationship shown in the drawings based on the orientation or positional relationship shown in the drawings or the orientation or positional relationship commonly used when the product of the application is used, only for the convenience of describing the application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the application.

[0079] Please refer to Figure 1 , Figure 1 The step flow chart of the cement mixing pile overall stability evaluation method of the application. A cement mixing pile overall stability evaluation method comprises the following steps:

[0080] S1, obtaining the soil layer information corresponding to different depth sections of each mixing pile in the foundation to be evaluated, the soil layer information including the soil layer type and the soil layer parameters corresponding to the soil layer type;

[0081] S2, determining the most dangerous sliding surface and the sliding force of the most dangerous sliding surface in the foundation to be evaluated, and recording the pile section of the mixing pile passed by the most dangerous sliding surface as a target pile section, wherein the mixing pile is divided into different pile sections at different depth sections;

[0082] S3, obtaining the construction parameters of each target pile section, the construction parameters including the cement content, the water content, the mixing and soil cutting frequency per meter after spraying, and the mixing and soil cutting frequency per meter before spraying;

[0083] S4, pre-setting the age, for each target pile section, inputting the soil layer information corresponding to the target pile section, the construction parameters and the set age into the constructed pile quality prediction model to obtain the pile strength information of each target pile section;

[0084] S5, calculating the anti-sliding force based on the pile strength information corresponding to each target pile section;

[0085] S6, determining the overall stability of the foundation to be evaluated according to the ratio of the anti-sliding force to the sliding force.

[0086] In the step S1, a plurality of mixing piles are generally constructed on the foundation to be evaluated to reinforce the foundation, and the soil layer information corresponding to different depth sections of the foundation to be evaluated at the positions of the mixing piles under construction can be obtained. In combination with the survey of the foundation to be evaluated before construction, such as the core drilling in the construction area, the soil layer types of different depth sections are divided after the soil samples are taken out, and since the soil layer parameters of the same soil layer type may be different in different projects, the soil layer parameters of different soil layer types in the construction area are tested to obtain the soil layer parameters corresponding to the soil layer types, so as to form a survey report of the construction area. Therefore, according to the survey information, the soil layer parameters corresponding to each soil layer type can be determined. The setting of the depth section can be determined according to the required accuracy. On the one hand, a soil layer less than 0.5 meters will not be divided into a soil layer type, that is, even if there are two different soils within a range of 0.5 meters, they are treated as one soil layer type in actual application, so the depth section should not be less than 0.5 meters. In the embodiment, the depth section is 0.5 meters.

[0087] Further, in the step S1, the step of obtaining the soil layer information corresponding to different depth sections of the foundation to be evaluated at the positions of each mixing pile under construction comprises:

[0088] S11, determining a plurality of soil layer types contained in the foundation to be evaluated, and obtaining soil layer parameters of each soil layer type;

[0089] S12, obtaining monitoring information collected every preset collection time during the construction of the mixing pile under construction, the monitoring information including the under-penetration depth and the measured end resistance;

[0090] S13, calculating the calculated end resistance of each depth section during the construction of the mixing pile under construction based on the soil layer information corresponding to the under-penetration depth;

[0091] S14, determining whether the difference between the measured end resistance corresponding to the under-penetration depth and the calculated end resistance of the corresponding depth section is within a preset error interval;

[0092] S15, if yes, the soil layer type corresponding to the under-penetration depth is taken as the soil layer type of the corresponding depth section, and the soil layer information corresponding to different depth sections is obtained;

[0093] S16, if no, the soil layer type corresponding to the under-penetration depth is changed, and the steps S13 and S14 are repeated.

[0094] In the step S11, before the cement mixing pile construction of the foundation to be evaluated, the survey report of the foundation to be evaluated is obtained by surveying, the soil layer types corresponding to different depth sections of the survey hole and the soil layer parameters corresponding to each soil layer type are determined, and thus the multiple soil layer types contained in the foundation to be evaluated and the soil layer parameters of each soil layer type are determined.

[0095] In the step S12, the construction of the mixing pile is generally performed by using a mixing pile machine, and the mixing pile machine generally includes a mixing head, a conveying pipeline and a winch for driving the mixing head to ascend and descend. During the construction process of the mixing pile machine, the penetration depth and the load sensor tension in the construction process are periodically collected, and the load sensor tension F in the penetration process is counted in steps of 0.5 m. 拉 Again, F 实测端阻力 =G-F 拉 The measured end resistance is calculated, and thus the monitoring information is obtained.

[0096] In the step S13, the penetration depth section distance of the mixing pile machine at several collection times is taken as a unit step, the unit step is taken as an analysis section, the soil layer type and the soil layer information corresponding to the penetration depth are obtained from the survey report according to the penetration depth of the mixing head, the calculated end resistance of the depth section in the penetration construction process is calculated based on the obtained soil layer information according to a preset formula, and the calculated end resistance represents the mechanical properties in the calculated unit step range. Specifically, if the depth section is 0.5 m, that is, the unit step is 0.5 m, the calculated end resistance of the unit step of 0 to 0.5 m is calculated as the calculated end resistance at the depth of 0.5 m according to the preset formula, the calculated end resistance of the unit step of 0.5 to 1 m is calculated as the calculated end resistance at the depth of 1 m according to the preset formula, and the calculated end resistance of each depth section is calculated from top to bottom in this way.

[0097] Further, the soil layer parameters include cohesion, friction angle, unit weight and lateral pressure coefficient.

[0098] In the step S13, based on the soil layer information corresponding to the penetration depth, the step of calculating the calculated end resistance of each depth section in the penetration construction process of the mixing pile includes:

[0099] S131, since the side friction resistance accounts for a very small proportion compared with the end resistance, the side friction resistance received in the penetration process is ignored, and thus the calculated end resistance of each depth section in the penetration construction process of the mixing pile is calculated by the following formula:

[0100] F 推算端阻力 =σ1S 竖 (4);

[0101] S 竖 =πd 2 +n 叶 B·l·cosθ (5);

[0102]

[0103] σ3=σ zi k si (7);

[0104]

[0105] In the formula, F 推算端阻力 To calculate the end resistance, σ1 is the major principal stress at the ultimate equilibrium of the soil, and S 竖 The vertical projected area of ​​the mixing head of the mixing pile machine is the sum of the circular area of ​​the rotating rod and the projected area of ​​the mixing blades, n. 叶 σ3 is the number of mixing blades in the mixing pile machine, σ3 is the minor principal stress at the soil's ultimate equilibrium, d is the drill rod diameter of the mixing pile machine, and σd is the number of mixing blades in the mixing pile machine. zi Let be the vertical effective stress of the i-th overlying soil layer. Let c be the friction angle of the i-th soil layer. i h is the cohesion of the i-th soil layer. si Let k be the thickness of the i-th soil layer. si Let γ be the lateral pressure coefficient of the i-th soil layer. si Let γ be the unit weight of the i-th soil layer. w h represents the specific gravity of water. w Because the water is deep.

[0106] In step 131 above, the number of mixing blades of the mixing pile machine is generally two, so formula (5) can be expressed as S 竖 =πd 2 +2B·l·cosθ.

[0107] In the steps S14 to S16, the calculated end resistance is compared with the corresponding measured end resistance. If the difference between the calculated end resistance and the measured end resistance is within the preset error range, it is indicated that the calculated end resistance is close to the measured end resistance, and the soil layer type corresponding to the penetration depth is close to the soil layer type of the corresponding depth section. Therefore, the soil layer type corresponding to the penetration depth is taken as the soil layer type of the corresponding depth section. If the difference between the calculated end resistance and the measured end resistance is not within the preset error range, it is indicated that the calculated end resistance is greatly different from the measured end resistance, and the soil layer type corresponding to the penetration depth is different from the soil layer type of the corresponding depth section. Therefore, the soil layer type corresponding to the penetration depth needs to be changed. One soil layer type can be selected from the multiple soil layer types contained in the foundation to be evaluated as the soil layer type corresponding to the penetration depth, and then the steps S13 and S14 are repeated until the difference between the calculated end resistance and the measured end resistance is within the preset error range. The soil layer type of the penetration depth obtained by the last change is taken as the soil layer type corresponding to the corresponding depth section, so as to obtain the actual soil layer types corresponding to different depth sections.

[0108] In the step S2, a typical section of the foundation to be evaluated for overall stability calculation is selected. The typical section can be a section involved, or a section where a pile segment is found to be unqualified in detection. Then, the calculation book provided by the design data is used to determine the most dangerous sliding surface and the sliding force of the typical section. Alternatively, the finite element or discrete element analysis can be used to directly determine the most dangerous sliding surface and the sliding force through the stress field and displacement field distribution. This is the prior art, and will not be described here. The mixing pile is divided into different pile segments according to different depth sections, that is, each pile segment of the mixing pile corresponds to each depth section, and the length of the pile segment is consistent with the length of the depth section. Then, the pile segment of the mixing pile through which the most dangerous sliding surface passes is recorded as a target pile segment, as shown in FIG. 2. Figure 2

[0109] In the step S3, the step of obtaining the construction parameters of each target pile segment includes:

[0110] S31, obtaining construction collection data of the mixing pile recorded every interval time in the construction process. The construction collection data includes recording time, real-time mortar injection flow, real-time water injection flow, real-time penetration speed, real-time lifting speed, real-time rotation speed, and mixing head end elevation.

[0111] S32, based on the obtained construction collection data, the construction parameters of the target pile segment are counted.

[0112] ​In the above steps S31 to S32, the stirring head of the stirring pile machine comprises a clamp, a plurality of drill rods arranged on the clamp, a motor connected with the plurality of drill rods for driving the rotation of the drill rods, a central rod arranged on the motor and located between the plurality of drill rods, a plurality of stirring heads arranged at the bottom of the plurality of drill rods respectively, and a drill bit holder arranged on the plurality of stirring heads. The stirring head is provided with a plurality of layers of stirring blades, each layer of stirring blades comprises a plurality of stirring blades arranged in the circumferential direction of the drill bit, the central rod is hollow inside, the bottom end of the outer side wall of the central rod is provided with an upper spray port, the bottom end of the outer side wall of the drill bit is provided with a lower spray port, the upper spray port and the lower spray port are connected with the conveying pipeline through the first connecting pipeline respectively, the conveying pipeline is connected with the mortar pump and the water pump through different second connecting pipelines, the second connecting pipeline connected with the mortar pump is provided with a mortar flow meter, the second connecting pipeline connected with the water pump is provided with a water flow meter, and the conveying pipeline is used for conveying cement mortar or water. Therefore, when the stirring pile machine is used to construct the stirring pile, the stirring pile machine will record the real-time mortar flow Q 浆t , the real-time water flow Q 水t , the real-time penetration speed V 下t , the real-time lifting speed V 上t , the real-time rotation speed n t and the drill bit end elevation H t every preset interval time during the construction process, and the recording time T t is combined to form construction collection data, which is the prior art and will not be described here. The preset interval time is usually 5 seconds. Then, based on the recording time T t , the real-time mortar flow Q 浆t , the real-time water flow Q 水t , the real-time penetration speed V 下t , the real-time lifting speed V 上t , the real-time rotation speed n t and the drill bit end elevation H t recorded by the stirring pile every preset interval time during the construction process, the cement content, the water content, the stirring and cutting soil frequency per meter after mortar spraying and the stirring and cutting soil frequency per meter before mortar spraying in the target pile section are counted, so as to obtain the construction parameters of the target pile section.

[0113] To realize a general statistical method, further, in the step of obtaining the construction collection data recorded by the stirring pile every preset interval time during the construction process, the construction process of the stirring pile needs to meet a preset precondition, and the precondition comprises:

[0114] a. The stirring head of the stirring pile machine has an upper spray port and a lower spray port, and the upper spray port or the lower spray port is used for spraying mortar or water when the stirring head is lifted or penetrated;

[0115] b. The interval time is not more than the preset conversion time when changing from mortar to water or from water to mortar. The general conversion time is set to 1 minute. The main reason is that sometimes water is sprayed again after a period of time, and the interval time is long or short. If the time is too long when changing from mortar to water, it is difficult to distinguish from the original data processing process whether the pipeline is filled with water or mortar before spraying water, and it is impossible to determine whether the mortar and water are converted. When the construction needs to change from mortar to water, the pump is usually closed and the other pump is started immediately. Here, the interval is not more than 1 minute, which is mainly convenient for program setting, and can also avoid the situation that some construction data is 0 due to abnormal data acquisition, leading to misjudgment.

[0116] c. After each construction, the pipeline needs to be flushed with water to avoid pipe blockage caused by residual cement mortar. Therefore, before the construction of the mixing pile machine, the conveying pipeline of the mixing pile machine is in a full water state.

[0117] In addition, according to the specific structure of the mixing pile machine, the volume V of the conveying pipeline can be obtained 管 , the number of layers n of the mixing blade 层 , the number n of mixing blades per layer 叶 , the distance L between the upper nozzle and the lower nozzle 喷口 . The volume of the first connecting pipe between the upper nozzle and the lower nozzle and the conveying pipeline is much smaller than the volume of the conveying pipeline, which can be ignored when statistical construction parameters.

[0118] Based on the obtained construction acquisition data, the steps of statistical construction parameters of the target pile section include:

[0119] S321. Select a construction acquisition data in time sequence from the obtained construction acquisition data, obtain the real-time mortar flow and real-time water flow corresponding to the selected construction acquisition data according to the preset rule, and obtain the real-time mortar flow and real-time water flow corresponding to each construction acquisition data.

[0120] S322. For each construction acquisition data, determine the construction acquisition data corresponding to the depth section of the target pile section according to the real-time lifting speed and the elevation of the mixing head end in the construction acquisition data, and record it as the target construction acquisition data.

[0121] S323. Calculate the cement parameter corresponding to the target pile section according to formula (9), and calculate the water yield corresponding to the target pile section according to formula (10), wherein formula (9) is as follows:

[0122]

[0123] In the formula, a c is the cement content, ∑Q 浆 is the sum of the real-time mortar flow of the target construction acquisition data, and p水泥浆 Where is the density of cement slurry, μ is the water-cement ratio, A is the treatment area of ​​the mixing pile, and L is the length of the target pile segment;

[0124] Formula (10) is as follows:

[0125]

[0126] In the formula, a w For water content, ∑Q 水 ρ is the sum of real-time effluent flow rates collected during the target construction. 水 The density of water;

[0127] S324. Group the target construction data collection data corresponding to real-time slurry flow rates greater than zero into one group, and determine the initial slurry flow time and minimum slurry flow elevation based on the target construction data collection data in this group.

[0128] S325. For each target construction data acquisition, if the recording time in the target construction data acquisition is greater than the initial time of slurry discharge, the target construction data acquisition is recorded as valid construction data acquisition; otherwise, the target construction data acquisition is recorded as invalid construction data acquisition.

[0129] S326. For each target construction data acquisition, if the difference between the drill bit tip elevation and the lowest slurry discharge elevation in the target construction data acquisition exceeds the distance between the upper and lower nozzles of the mixing head, then the number of effective mixing blades n corresponding to the target construction data acquisition is... 有效 =n 层 ×n 叶 Otherwise, the number of effective mixing blades n corresponding to the target construction data collection is... 有效 = n layers total × n blades, n layers total = Ht - H discharge min L nozzle * n layers, where Ht is the elevation of the drill bit end, H discharge min is the minimum discharge elevation, and L nozzle is the distance between the upper and lower nozzles of the mixing head;

[0130] S327. Include effective construction data in the statistics and calculate the effective mixing times N for each effective construction data collection. 有效 =T t ·n t ·n 有效 Then, sum the effective mixing times of the valid construction data corresponding to the target pile segment to obtain the number of mixing and cutting times per meter after shotcreting for the target pile segment, n. t For real-time rotational speed, T t The preset interval time;

[0131] S328. Include invalid construction data in the statistics and calculate the number of pre-mixing times N for each invalid construction data collection. 预 =T t ·nt ·n 有效 The pre-mixing times of the invalid construction collection data corresponding to the target pile section are summed up to obtain the number of mixing and cutting soil per meter before the target pile section is sprayed.

[0132] The above statistical process is prior art and will not be described again.

[0133] In the above step S4, the pile quality prediction model is constructed in advance, the pile quality prediction model can adopt a neural network algorithm, and of course other algorithms can also be adopted, the input of the pile quality prediction model is the soil layer type, the soil layer parameter corresponding to the soil layer type, the construction parameter and the age, and the output of the pile quality prediction model is a plurality of pile strength ranges and the probability of each pile strength range.

[0134] The construction process of the pile quality prediction model is as follows:

[0135] (1) Obtain the historical construction information and detection information of a plurality of constructed piles, the historical construction information includes the soil layer information corresponding to different depth sections in the area where the constructed piles are located and the construction collection data recorded by the constructed piles every preset interval time in the construction process, and the detection information includes the detection age of the detection of the constructed piles and the pile strength range of the different depth sections of the constructed piles at the detection age;

[0136] (2) For each constructed pile, based on the construction collection data recorded by the constructed pile every preset interval time in the construction process, the construction parameters of the constructed pile at different depth sections are counted;

[0137] (3) Based on the soil layer information corresponding to the different depth sections of the plurality of constructed piles, the construction parameters, the detection age and the pile strength range, a data set is constructed;

[0138] (4) The data set is divided into a training set and a test set, and the training set and the test set are used to train the pile quality prediction model to obtain the trained pile quality prediction model, and the output result of the pile quality prediction model is adjusted so that the pile quality prediction model outputs a plurality of pile strength ranges and the probability of each pile strength range.

[0139] In the step (1), for some constructed piles, the constructed piles are cored after reaching a certain age, the cement-soil core samples are taken out and strength tests are performed to obtain the pile strength at different depth sections, and the pile strength range is determined according to the pile strength to obtain the detection information. For the detected constructed piles, there are pile numbers, detection ages and elevations, and the soil layer information corresponding to different depth sections in the area of the constructed piles can be obtained according to the nearest survey hole. The construction of the mixing pile is generally performed by a mixing pile machine, and the mixing pile machine records the real-time mortar spraying flow Q 浆t , real-time water spraying flow Q 水t , real-time penetration speed V 下t , real-time lifting speed V 上t , real-time rotation speed n t and drill bit end elevation H t at preset interval times during the construction, and the construction data is formed by combining the recording time T t , so that the historical construction information and detection information of a plurality of constructed piles in the previous project can be obtained

[0140] In the step (2), for each constructed pile, the cement content, water content, mixing and cutting soil times per meter after mortar spraying and mixing and cutting soil times per meter before mortar spraying in different depth sections are counted based on the recording time T t , real-time mortar spraying flow Q 浆t , real-time water spraying flow Q 水t , real-time penetration speed V 下t , real-time lifting speed V 上t , real-time rotation speed n t and drill bit end elevation H t recorded by the constructed pile at preset interval times during the construction process, so as to obtain the construction parameters of the constructed pile at different depth sections. The construction process of the constructed pile meets the preset precondition, and the specific counting method can refer to steps S321 to S327, which will not be described here.

[0141] In the above steps (3) and (4), for each constructed pile, the corresponding soil layer information, construction parameters, detection age and pile strength range of each depth section of the constructed pile are saved to form a sample group, and then a plurality of sample groups corresponding to each constructed pile are obtained, and then a data set is constructed based on the plurality of sample groups of the plurality of constructed piles. 80% of the data in the data set is used as a training set, and the remaining 20% is used as a training set. The soil layer information, construction parameters and detection age in each sample group in the training set and test set are used as input, and the corresponding pile strength range in each sample group is used as output. The pile quality prediction model is trained, the hyperparameters of the pile quality prediction model are continuously corrected, so that the accuracy of the pile quality prediction model reaches more than 90%, thereby obtaining a trained pile quality prediction model. In the prediction process of the pile quality prediction model, finally, the probabilities of a plurality of pile strength ranges are compared, and then the pile strength range with the highest probability is taken as the output result. Therefore, based on the prediction process of the pile quality prediction model, the probabilities of the plurality of pile strength ranges predicted by the pile quality prediction model can be traced back, and then the output result of the pile quality prediction model can be adjusted, so that the pile quality prediction model outputs a plurality of pile strength ranges and the probabilities of each pile strength range.

[0142] And every time a new project is completed, the historical construction information and detection information of the test constructed piles in the project are included in the total data set, and 80% of the historical data is randomly extracted again as a training set, and the remaining 20% is used as a test set. When the accuracy of the model reaches a certain index (such as an accuracy of 90%), a new pile quality prediction model can be formed for the pile quality prediction model of the next project. In this way, as the number of projects increases, the pile quality prediction model will become more and more perfect.

[0143] In the above step S5, the pile strength information includes a plurality of pile strength ranges and the probabilities of each pile strength range.

[0144] Based on the pile strength information corresponding to each target depth section, the step of calculating the anti-sliding force includes:

[0145] S51, the expected value of the strength of the target pile section is calculated by the following formula:

[0146]

[0147] In the formula, E q is the expected value of the strength of the target pile section, m is the number of pile strength ranges, a i is the characteristic strength of the i-th pile strength range, q i下限 is the lower limit boundary value of the i-th pile strength range, q i上限 is the upper limit boundary value of the i-th pile strength range, q m下限 is the lower limit boundary value of the m-th pile strength range, Pi The probability of the i-th pile strength range;

[0148] S52. Calculate the anti-skid force using the following formula:

[0149]

[0150] In the formula, F 抗滑 For anti-slip force, n 桩 Let A be the number of mixing piles in the cross-section, and E be the cross-sectional area of ​​the mixing piles. iq Let be the expected intensity value of the i-th target depth segment.

[0151] In step S51 above, the number of pile strength ranges can be set to four, namely [0MPa, 1MPa), [1MPa, 2MPa), [2MPa, 3MPa), and greater than or equal to 3MPa. Then, the characteristic strengths of each pile strength range are as follows: And 3, therefore the expected strength value e of the target pile segment iq =0.5×P i1 +1.5×P i2 +2.5×P i3 +3×P i4 In the formula, P i1 P represents the probability of the first pile strength range of the i-th target pile segment. i2 P represents the probability of the second pile strength range for the i-th target pile segment. i3 P represents the probability of the first pile strength range of the i-th target pile segment. i4 The probability of the fourth pile strength range for the i-th target pile segment.

[0152] In step S52 above, the pile strength of each target pile segment on the most dangerous sliding surface is statistically analyzed, and its shear strength is calculated. The shear strength is then reduced by half of the expected pile strength. Combined with the cross-sectional area of ​​the pile body and the number of mixing piles passing through the most dangerous sliding surface, the anti-sliding force can be calculated.

[0153] In step S6 above, the ratio of anti-slip force to sliding force is calculated, and it is determined whether the ratio of anti-slip force to sliding force exceeds the required safety factor. If the ratio exceeds the safety factor, the foundation to be evaluated is determined to be stable overall; otherwise, the foundation to be evaluated is determined to be unstable overall.

[0154] Please see Figure 3 , Figure 3 This is a schematic diagram of the modules of the cement mixing pile overall stability evaluation system of the present invention. Corresponding to the aforementioned embodiments of the cement mixing pile overall stability evaluation method of the present invention, the present invention also provides a cement mixing pile overall stability evaluation system, including:

[0155] The first acquisition module 10 is used to acquire soil layer information corresponding to different depths at the location of each mixing pile of the foundation to be evaluated. The soil layer information includes soil layer type and soil layer parameters corresponding to the soil layer type.

[0156] The determination module 20 is used to determine the most dangerous slip surface and the sliding force of the most dangerous slip surface in the foundation to be evaluated. The pile segment of the mixing pile that the most dangerous slip surface passes through is recorded as the target pile segment, and the mixing pile is divided into different pile segments according to different depths.

[0157] The second acquisition module 30 is used to acquire the construction parameters of each target pile segment. The construction parameters include cement content, water content, number of mixing and cutting per meter after shotcreting and number of mixing and cutting per meter before shotcreting.

[0158] Input module 40 is used to pre-set the age. For each target pile segment, the soil layer information, construction parameters and set age corresponding to the target pile segment are input into the constructed pile quality prediction model to obtain the pile strength information of each target pile segment.

[0159] Calculation module 50 is used to calculate the anti-sliding force based on the pile strength information corresponding to each target pile segment;

[0160] Evaluation module 60 is used to determine the overall stability of the foundation to be evaluated based on the ratio of anti-sliding force to sliding force.

[0161] Furthermore, the pile strength information includes multiple pile strength ranges and the probability of each pile strength range;

[0162] The calculation module 50 includes:

[0163] The first calculation submodule is used to calculate the expected strength value of the target pile segment using the following formula:

[0164]

[0165] In the formula, E q Let m be the expected strength value of the target pile segment, m be the number of pile strength ranges, and a be the expected strength value of the target pile segment. i Let q be the characteristic strength of the i-th pile strength range. i下限 Let q be the lower limit boundary value of the i-th pile strength range. i上限 Let q be the upper boundary value of the i-th pile strength range. m下限 P is the lower limit boundary value of the m-th pile strength range. i The probability of the i-th pile strength range;

[0166] The second calculation submodule is used to calculate the anti-slip force using the following formula:

[0167]

[0168] F 抗滑 is the anti-sliding force, n 桩 is the number of mixing piles in the cross section, A is the cross-sectional area of the mixing pile, E iq is the strength expectation value of the i-th target depth section.

[0169] Further, the first acquisition module 10 comprises:

[0170] A determination submodule is configured to determine a plurality of soil layer types contained in the foundation to be evaluated, and acquire soil layer parameters of each soil layer type;

[0171] A first acquisition submodule is configured to acquire monitoring information collected every preset collection time during the construction process of the mixing pile, the monitoring information comprising a penetration depth and a measured end resistance;

[0172] A third calculation submodule is configured to calculate a calculated end resistance of each depth section during the construction process of the mixing pile based on soil layer information corresponding to the penetration depth;

[0173] A judgment submodule is configured to judge whether a difference between the measured end resistance corresponding to the penetration depth and the calculated end resistance of the corresponding depth section is within a preset error interval;

[0174] A obtaining submodule is configured to, if the judgment submodule judges yes, take the soil layer type corresponding to the penetration depth as the soil layer type of the corresponding depth section, and obtain soil layer information corresponding to different depth sections;

[0175] A repeating submodule is configured to, if the judgment submodule judges no, change the soil layer type corresponding to the penetration depth, and repeat the third calculation submodule and the judgment submodule.

[0176] Further, the soil layer parameters comprise cohesion, friction angle, unit weight, and lateral pressure coefficient;

[0177] The third calculation submodule comprises:

[0178] A calculation unit is configured to calculate the calculated end resistance of each depth section during the construction process of the mixing pile by the following formula:

[0179] F 推算端阻力 = σ1S 竖 (4);

[0180] S 竖 = πd 2 +n 叶 B·l·cosθ (5);

[0181]

[0182] σ3= σ zi k si (7);

[0183]

[0184] F = 0.5 * (σ1 - σ3) * d2 推算端阻力 is the end resistance, σ1 is the maximum principal stress of the soil in limit equilibrium, S 竖 is the vertical projection area of the mixing head of the mixing pile machine, n 叶 is the number of mixing blades of the mixing pile machine, σ3 is the minimum principal stress of the soil in limit equilibrium, d is the diameter of the drill rod of the mixing pile machine, σ zi is the vertical effective stress of the overlying soil layer of the i-th layer, is the friction angle of the i-th layer of soil, c i is the cohesion of the i-th layer of soil, h si is the thickness of the i-th layer of soil, k si is the lateral pressure coefficient of the i-th layer of soil, γ si is the unit weight of the i-th layer of soil, γ w is the unit weight of water, h w is the water depth.

[0185] Further, the second acquisition module 30 comprises:

[0186] The second acquisition submodule is configured to acquire construction collection data of the mixing pile recorded at every interval time during the construction process, the construction collection data comprising recorded time, real-time mortar injection flow, real-time water injection flow, real-time penetration speed, real-time lifting speed, real-time rotation speed, and mixing head end elevation.

[0187] The statistical submodule is configured to statistically acquire construction parameters of the target pile section based on the acquired construction collection data.

[0188] Further, in the second acquisition submodule, the construction process of the mixing pile needs to satisfy preset prerequisites, the prerequisites comprising:

[0189] a. The mixing head of the mixing pile machine is provided with an upper nozzle and a lower nozzle, and the upper nozzle is used to inject mortar or water when the mixing head is lifted, and the lower nozzle is used to inject mortar or water when the mixing head is penetrated;

[0190] b. When the mortar injection is switched to water injection or the water injection is switched to mortar injection, the interval time is not more than a preset switching time;

[0191] c. Before the mixing pile machine is used for construction, the conveying pipeline of the mixing pile machine is in a state of being filled with water;

[0192] The statistical submodule comprises:

[0193] The selecting unit is configured to sequentially select one construction collection data from the acquired construction collection data in time sequence, and obtain real-time slurry discharge flow and real-time water discharge flow corresponding to the selected construction collection data according to a preset rule, so as to obtain real-time slurry discharge flow and real-time water discharge flow corresponding to each construction collection data;

[0194] The first determining unit is configured to, for each construction collection data, determine construction collection data corresponding to a depth section where the target pile section is located according to real-time lifting speed and end elevation of the mixing head in the construction collection data, and record the construction collection data as target construction collection data;

[0195] The first calculating unit is configured to calculate cement parameters corresponding to the target pile section according to formula (9), and calculate water yield corresponding to the target pile section according to formula (10), wherein formula (9) is as follows:

[0196]

[0197] In the formula, a c is cement content, ∑Q 浆 is a sum of real-time slurry discharge flow of the target construction collection data, ρ 水泥浆 is cement slurry density, μ is water-cement ratio, A is treatment area of the mixing pile, and L is length of the target pile section;

[0198] Formula (10) is as follows:

[0199]

[0200] In the formula, a w is water content, ∑Q 水 is a sum of real-time water discharge flow of the target construction collection data, ρ 水 is water density;

[0201] The second determining unit is configured to classify target construction collection data corresponding to real-time slurry discharge flow greater than zero into a group, and determine slurry initial time and minimum slurry discharge elevation according to target construction collection data in the group;

[0202] The marking unit is configured to, for each target construction collection data, if record time in the target construction collection data is greater than the slurry initial time, record the target construction collection data as valid construction collection data, or else record the target construction collection data as invalid construction collection data;

[0203] The first statistical unit is configured to, for each target construction collection data, if a value obtained by subtracting the minimum slurry discharge elevation from the end elevation of the drill bit in the target construction collection data exceeds a distance between upper and lower nozzles of the mixing head, the number n 有效 of effective mixing blades corresponding to the target construction collection data is n 层 ×n叶 , otherwise the target construction collection data corresponding to the effective stirring number of stirring blades n 有效 = n 层整 x n 叶 , wherein H t is the drill bit end elevation, H 出浆nin is the lowest slurry discharge elevation, L 喷口 is the spacing between the upper and lower nozzles of the mixing head.

[0204] The second statistical unit is used to include the effective construction collection data in statistics, and calculate the effective stirring frequency N 有效 = T t · n t · n 有效 of each effective construction collection data, and then sum the effective stirring frequencies of the effective construction collection data corresponding to the target pile section to obtain the stirring and cutting soil frequency per meter after the target pile section is sprayed. t is the real-time rotating speed, and T t is the preset interval time.

[0205] The third statistical unit is used to include the invalid construction collection data in statistics, and calculate the pre-stirring frequency N 预 = T t · n t · n 有效 of each invalid construction collection data, and then sum the pre-stirring frequencies of the invalid construction collection data corresponding to the target pile section to obtain the stirring and cutting soil frequency per meter before the target pile section is sprayed.

[0206] The implementation process of the functions and roles of each module and sub-module in the above system is specifically described in the implementation process of the corresponding steps in the above method, and will not be repeated here.

[0207] For the system embodiment, since it basically corresponds to the method embodiment, please refer to the part of the method embodiment for the related description. The system embodiment described above is only illustrative, and the units described as separate components can or can not be physically separated, and the components displayed as units can or can not be physical units.

[0208] Corresponding to the above-described embodiments of the cement mixing pile overall stability evaluation method, the present application also provides an electronic device, which can include: a processor; a memory for storing an executable computer program; wherein the processor implements the cement mixing pile overall stability evaluation method in any of the above method embodiments when executing the computer program.

[0209] Embodiments of the cement mixing pile overall stability evaluation method and system provided by the present application can be applied to electronic devices. Taking software implementation as an example, as a logically meaningful device, it is formed by reading the corresponding computer program instructions in the non-volatile memory into the memory for running by the processor of the electronic device in which it is located. From the hardware level, as shown in Figure 4 In addition to the processor, memory, network interface, and non-volatile memory shown in Figure 4 The electronic device can also include other hardware such as a camera module, or other hardware according to the actual function of the electronic device, which will not be described in detail.

[0210] Corresponding to the embodiments of the cement mixing pile overall stability evaluation method described above, the present application also provides a computer readable storage medium having a computer program stored thereon, wherein the computer program is executed by a processor to implement the cement mixing pile overall stability evaluation method in any of the method embodiments described above.

[0211] Embodiments of the present application can be in the form of a computer program product implemented on one or more storage media (including but not limited to disk storage, CD-ROM, optical storage, etc.) containing program code. The computer readable storage medium can include: permanent or non-permanent removable or non-removable media. The information storage function of the computer readable storage medium can be realized by any implementable method or technology. The information can be computer readable instructions, data structures, program models or other data.

[0212] In addition, the computer readable storage medium includes but is not limited to: phase change memory (PRAM), static random access memory (SRAM), dynamic random access memory (DRAM), other types of random access memory (RAM), read-only memory (ROM), electrically erasable programmable read-only memory (EEPROM), flash memory or other memory technology, compact disc read-only memory (CD-ROM), digital versatile disc (DVD) or other optical storage, magnetic cassette, magnetic tape disk storage or other magnetic storage device, or other non-transmission medium that can be used to store information accessible by a computing device.

[0213] Compared with the prior art, the application has the beneficial effects that: the true soil layer type and the soil layer parameters of different depth sections of the mixing pile are obtained, the construction parameters of the target pile section through which the most dangerous sliding surface passes are determined, the soil layer parameters, the construction parameters and the age of the target pile section are used as inputs, the constructed pile quality prediction model is used to obtain the pile strength information of each target pile section, and the ratio of the anti-sliding force of the most dangerous sliding surface to the theoretical sliding force is calculated as the evaluation standard of the overall stability of the foundation to be evaluated; the application can fully consider the actual soil layer conditions and the actual construction parameters, fully utilize the related data actually collected by the construction pile, avoid the survey cost of additional static sounding, dynamic sounding and drilling core taking, and greatly improve the reliability of the overall stability evaluation of the foundation to be evaluated.

[0214] The above is only a preferred embodiment of the present application, and does not limit the present application in any form. Any simple modification, equivalent change and modification of the above embodiment based on the technical essence of the present application, without departing from the technical solution of the present application, still belongs to the scope of the technical solution of the present application.

Claims

1. A method for evaluating the stability of a cement deep mixing pile, characterized by, The method comprises the following steps: S1, acquiring soil layer information corresponding to different depth sections of each mixing pile in the to-be-evaluated foundation, the soil layer information comprising a soil layer type and soil layer parameters corresponding to the soil layer type; S2, determining a most dangerous sliding surface and a sliding force of the most dangerous sliding surface in the to-be-evaluated foundation, and recording a pile section of a mixing pile passed by the most dangerous sliding surface as a target pile section, wherein the pile section of the mixing pile is divided into nodes in terms of depth sections; S3, acquiring construction parameters of each target pile section, the construction parameters comprising a cement mixing amount, a water mixing amount, a mixing and soil cutting frequency per meter after jet grouting, and a mixing and soil cutting frequency per meter before jet grouting; S4, presetting an age period, and inputting, for each target pile section, the soil layer information corresponding to the target pile section, the construction parameters, and the preset age period into a constructed pile quality prediction model to obtain pile strength information of each target pile section; S5, calculating a sliding resistance force based on the pile strength information corresponding to each target pile section; S6, determining an overall stability of the to-be-evaluated foundation according to a ratio of the sliding resistance force to the sliding force.

2. The method for evaluating the stability of cement deep mixing columns according to claim 1, characterized in that, The pile strength information comprises a plurality of pile strength ranges and probabilities of each pile strength range; The step of calculating the sliding resistance force based on the pile strength information corresponding to each target depth section comprises: S51, calculating an expected value of the strength of the target pile section by the following formula: In the formula, E q is the expected value of the strength of the target pile section, m is the number of pile strength ranges, a i is the characteristic strength of the i th pile strength range, q i下限 is the lower limit boundary value of the i th pile strength range, q i上限 is the upper limit boundary value of the i th pile strength range, q m下限 is the lower limit boundary value of the m th pile strength range, P i is the probability of the i th pile strength range; S52, calculating the sliding resistance force by the following formula: In the formula, F 抗滑 n is the anti-sliding force 桩 is the number of mixing piles in the cross section, A is the cross-sectional area of the mixing pile, E iq is the strength expectation value of the i-th target depth section.

3. The method for evaluating the stability of cement deep mixing columns according to claim 1, characterized in that, The step of acquiring the soil layer information corresponding to different depth sections of each mixing pile in the to-be-evaluated foundation comprises: S11, determining a plurality of soil layer types contained in the to-be-evaluated foundation, and acquiring soil layer parameters of each soil layer type; S12, acquiring monitoring information collected every preset collection time during a down-penetration construction process of the mixing pile, the monitoring information comprising a down-penetration depth and a measured end resistance; S13, calculating a calculated end resistance of each depth section during the down-penetration construction process of the mixing pile based on soil layer information corresponding to the down-penetration depth; S14, judging whether a difference between the measured end resistance corresponding to the down-penetration depth and the calculated end resistance of the corresponding depth section is within a preset error interval; S15, if yes, taking the soil layer type corresponding to the down-penetration depth as the soil layer type of the corresponding depth section to obtain the soil layer information corresponding to different depth sections; S16, if no, changing the soil layer type corresponding to the down-penetration depth, and repeating steps S13 and S14.

4. The method for evaluating the stability of cement deep mixing columns according to claim 3, characterized in that, The soil layer parameters comprise cohesion, a friction angle, a unit weight, and a lateral pressure coefficient; The step of calculating the calculated end resistance of each depth section during the down-penetration construction process of the mixing pile based on the soil layer information corresponding to the down-penetration depth comprises: The calculated end resistance of each depth section during the down-penetration construction process of the mixing pile is calculated by the following formula: F 推算端阻力 = σ1S 竖 (4); S 竖 = πd 2 +n 叶 B·l·cosθ (5); σ3= σ zi k si (7); where F 推算端阻力 is the end resistance, σ1 is the major principal stress of the soil at limit equilibrium, S 竖 is the vertical projection area of the mixing head of the mixing pile machine, n 叶 is the number of mixing blades of the mixing pile machine, σ3 is the minor principal stress of the soil at limit equilibrium, d is the diameter of the drill pipe of the mixing pile machine, σ zi is the vertical effective stress of the overlying soil layer of the i-th layer, is the friction angle of the i-th layer of soil, c i is the cohesion of the i-th layer of soil, h si is the thickness of the i-th layer of soil, k si is the lateral pressure coefficient of the i-th layer of soil, γ si is the unit weight of the i-th layer of soil, γ w is the unit weight of water, h w is the water depth.

5. The method for evaluating the stability of cement deep mixing columns according to claim 1, characterized in that, The step of acquiring the construction parameters of each target pile section comprises: S31, acquiring construction collection data recorded every interval time during the construction process of the mixing pile, the construction collection data comprising a recording time, a real-time jet grouting flow, a real-time water jet flow, a real-time penetration speed, a real-time lifting speed, a real-time rotating speed, and a height of an end of a mixing head; S32, statistically acquiring the construction parameters of the target pile section based on the acquired construction collection data.

6. The method for evaluating the stability of cement deep mixing columns according to claim 5, characterized in that, The preset precondition for the construction process of the mixing pile includes: The mixing head of the mixing pile machine has an upper nozzle and a lower nozzle, and the upper nozzle is used to spray mortar or water when the mixing head is lifted, and the lower nozzle is used to spray mortar or water when the mixing head is lowered; The interval time is not more than the preset conversion time when the mortar spraying is converted to water spraying or the water spraying is converted to mortar spraying; Before the mixing pile machine is used for construction, the conveying pipeline of the mixing pile machine is in a full water state; The step of obtaining the construction parameters of the target pile section based on the obtained construction collection data includes: S321, from the obtained construction collection data, a construction collection data is selected in time sequence, the real-time mortar flow and the real-time water flow corresponding to the selected construction collection data are obtained according to the preset rule, so as to obtain the real-time mortar flow and the real-time water flow corresponding to each construction collection data; S322, for each construction collection data, the real-time lifting speed and the mixing head end elevation in the construction collection data are used to determine the construction collection data corresponding to the depth section where the target pile section is located, and the target construction collection data is recorded; S323, the cement parameter corresponding to the target pile section is calculated according to formula (9), and the water yield corresponding to the target pile section is calculated according to formula (10), wherein formula (9) is as follows: In the formula, a c is the cement content, ∑Q 浆 is the sum of the real-time slurry flow of the target construction collection data, ρ 水泥浆 is the cement slurry density, μ is the water-cement ratio, A is the treatment area of the mixing pile, and L is the length of the target pile section. Formula (10) is as follows: In the formula, a w is the water content, ∑Q 水 is the sum of real-time water flow of target construction data collection, ρ 水 is the water density; S324, the target construction collection data corresponding to the real-time mortar flow greater than zero is classified into a group, and the initial mortar time and the minimum mortar elevation are determined according to the target construction collection data in the group; S325, for each target construction collection data, if the recording time in the target construction collection data is greater than the initial mortar time, the target construction collection data is recorded as valid construction collection data, otherwise the target construction collection data is recorded as invalid construction collection data; S326、for each of the target construction acquisition data, if the value of the drill bit end elevation minus the lowest slurry outlet elevation in the target construction acquisition data exceeds the interval between the upper and lower nozzles of the mixing head, the number of effective mixing blades n corresponding to the target construction acquisition data 有效 = n 层 × n 叶 , otherwise the number of effective mixing blades n corresponding to the target construction acquisition data 有效 = n 层整 × n 叶 , wherein H t is the drill bit end elevation, H 出浆min is the lowest slurry outlet elevation, and L 喷口 is the interval between the upper and lower nozzles of the mixing head. S327, the effective construction collection data is brought into statistics, and the effective stirring times N of each effective construction collection data is calculated 有效 = T t ·n t ·n 有效 The effective stirring times of the effective construction collection data corresponding to the target pile section are summed up, and the stirring and cutting soil times per meter after the target pile section is sprayed, n t is a real-time rotating speed, T t is a preset interval time; S328, invalid construction collection data is included in statistics, the pre-mixing number N of each invalid construction collection data is calculated 预 = T t ·n t ·n 有效 The pre-mixing number of the invalid construction collection data corresponding to the target pile section is summed up to obtain the cutting soil number per meter before the target pile section is sprayed.

7. A cement deep mixing pile overall stability evaluation system characterized by, It includes: The first acquisition module is used for acquiring the soil layer information corresponding to different depth sections in each mixing pile of the foundation to be evaluated, and the soil layer information includes the soil layer type and the soil layer parameter corresponding to the soil layer type; The determination module is used for determining the most dangerous sliding surface and the sliding force of the most dangerous sliding surface in the foundation to be evaluated, and the pile section of the mixing pile passing through the most dangerous sliding surface is recorded as the target pile section, wherein the mixing pile is divided into different pile sections at different depth sections; The second acquisition module is used for acquiring the construction parameters of each target pile section, and the construction parameters include the cement content, the water content, the mixing and soil cutting frequency per meter after mortar spraying, and the mixing and soil cutting frequency per meter before mortar spraying; The input module is used for pre-setting the age, and for each target pile section, the soil layer information, the construction parameters and the set age corresponding to the target pile section are input into the constructed pile quality prediction model to obtain the pile strength information of each target pile section; The calculation module is used for calculating the anti-sliding force based on the pile strength information corresponding to each target pile section. An evaluation module is configured to determine the overall stability of the foundation to be evaluated according to the ratio of the anti-sliding force and the sliding force.

8. An electronic device, comprising: Comprise: a processor; a memory for storing an executable computer program; wherein the processor implements the steps of the method of any one of claims 1 to 6 when executing the computer program.

9. A computer readable storage medium having stored thereon a computer program, characterized in that, The computer program, when executed by the processor, implements the steps of the method of any one of claims 1 to 6.

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