CN114855748A - Output torque-based cement mixing pile soil layer identification method - Google Patents
Output torque-based cement mixing pile soil layer identification method Download PDFInfo
- Publication number
- CN114855748A CN114855748A CN202210569014.XA CN202210569014A CN114855748A CN 114855748 A CN114855748 A CN 114855748A CN 202210569014 A CN202210569014 A CN 202210569014A CN 114855748 A CN114855748 A CN 114855748A
- Authority
- CN
- China
- Prior art keywords
- torque
- soil
- soil layer
- depth section
- stirring head
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Granted
Links
Images
Classifications
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D1/00—Investigation of foundation soil in situ
- E02D1/02—Investigation of foundation soil in situ before construction work
- E02D1/022—Investigation of foundation soil in situ before construction work by investigating mechanical properties of the soil
-
- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D5/00—Bulkheads, piles, or other structural elements specially adapted to foundation engineering
- E02D5/22—Piles
- E02D5/34—Concrete or concrete-like piles cast in position ; Apparatus for making same
- E02D5/46—Concrete or concrete-like piles cast in position ; Apparatus for making same making in situ by forcing bonding agents into gravel fillings or the soil
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/10—Geometric CAD
- G06F30/13—Architectural design, e.g. computer-aided architectural design [CAAD] related to design of buildings, bridges, landscapes, production plants or roads
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F30/00—Computer-aided design [CAD]
- G06F30/20—Design optimisation, verification or simulation
-
- G—PHYSICS
- G06—COMPUTING; CALCULATING OR COUNTING
- G06F—ELECTRIC DIGITAL DATA PROCESSING
- G06F2119/00—Details relating to the type or aim of the analysis or the optimisation
- G06F2119/14—Force analysis or force optimisation, e.g. static or dynamic forces
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
- Y02W—CLIMATE CHANGE MITIGATION TECHNOLOGIES RELATED TO WASTEWATER TREATMENT OR WASTE MANAGEMENT
- Y02W30/00—Technologies for solid waste management
- Y02W30/50—Reuse, recycling or recovery technologies
- Y02W30/91—Use of waste materials as fillers for mortars or concrete
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Geometry (AREA)
- General Engineering & Computer Science (AREA)
- Theoretical Computer Science (AREA)
- Structural Engineering (AREA)
- Computer Hardware Design (AREA)
- Civil Engineering (AREA)
- General Physics & Mathematics (AREA)
- Life Sciences & Earth Sciences (AREA)
- General Life Sciences & Earth Sciences (AREA)
- Mining & Mineral Resources (AREA)
- Paleontology (AREA)
- Evolutionary Computation (AREA)
- Chemical & Material Sciences (AREA)
- Analytical Chemistry (AREA)
- Soil Sciences (AREA)
- Architecture (AREA)
- Computational Mathematics (AREA)
- Mathematical Analysis (AREA)
- Mathematical Optimization (AREA)
- Pure & Applied Mathematics (AREA)
- Consolidation Of Soil By Introduction Of Solidifying Substances Into Soil (AREA)
Abstract
A cement mixing pile soil layer identification method based on output torque comprises the following steps: determining multiple soil layer types contained in a construction area through reconnaissance, and acquiring physical and mechanical parameters of each soil layer type; obtaining a design construction depth, and dividing the design construction depth into a plurality of depth sections; before construction, acquiring friction torque between the pile embracing device and a drill rod corresponding to each depth section; in the construction process, when the stirring head descends to the bottom end of each depth section, recording the corresponding depth section as a target depth section, and calculating the driving torque for damaging each soil layer type when the stirring head is at the target depth section according to a preset calculation rule; and acquiring an actually measured torque measured by the torque sensor, and determining the soil layer type of the target depth section based on the driving torque and the actually measured torque obtained by calculation. According to the method, the soil layer types corresponding to different depths are identified through different torques required by the stirring head to destroy different soil layer types and the actually measured torques of the torque sensors.
Description
Technical Field
The invention belongs to the technical field of mixing pile construction, and particularly relates to a cement mixing pile soil layer identification method based on output torque.
Background
A deep cement-soil mixing pile is a mode of foundation treatment, and it uses cement as solidifying agent, and utilizes a special mixing machine to mix the solidifying agent with peripheral soil body by means of slurry-spraying mode in the deep portion of foundation, then produces physical and chemical reaction to make the soft soil be hardened into the excellent and good foundation with integrity, water stability and a certain strength. Different technological parameters need to be adopted for different soil layers during construction of the deep cement mixing pile, only 1 prospecting drill hole is usually formed in one construction area in engineering practice, and all mixing pile constructions adjust the construction technological parameters according to the soil layer distribution condition of the prospecting drill hole. However, a large number of engineering soil layers are complicated in distribution, and the actual construction soil layer distribution is not consistent with the exploration holes, so that the construction process parameters are not suitable for the soil layers, so that the construction quality of partial pile sections is poor, and even the piles are not formed.
Disclosure of Invention
The invention aims to provide a cement mixing pile soil layer identification method based on output torque, which identifies soil layer types corresponding to different depths through different torques required by a mixing head to damage different soil layer types and actual measurement torque of a torque sensor.
The invention is realized by the following technical scheme:
a cement mixing pile soil layer identification method based on output torque comprises a mixing assembly, wherein the mixing assembly comprises a pile embracing device, a plurality of drill rods arranged on the pile embracing device and a power head connected with the drill rods and used for driving drilling to rotate, a mixing head is arranged at the bottom end of each drill rod, a plurality of layers of blades are arranged on the outer side wall of the mixing head, a cutting blade is arranged at the bottom end of the mixing head, the mixing assembly further comprises an intelligent terminal, a torque sensor used for measuring the torque of the drill rods is arranged between the intelligent terminals, and the intelligent terminal is connected with the torque sensor;
the method comprises the following steps:
surveying a construction area, determining various soil layer types contained in the construction area, and acquiring physical and mechanical parameters of each soil layer type;
obtaining a design construction depth, and dividing the design construction depth into a plurality of depth sections;
before construction, acquiring friction torque between the pile gripper and the drill rod when the stirring head descends to the bottom end of each depth section, and acquiring the friction torque corresponding to each depth section;
in the construction process, when the stirring head descends to the bottom end of each depth section, the depth section where the stirring head is located is recorded as a target depth section, and the driving torque for damaging each soil layer type when the stirring head is located at the target depth section is calculated according to a preset calculation rule on the basis of the physical and mechanical parameters of each soil layer type and the friction torque corresponding to the target depth section;
and acquiring the actual measurement torque measured by the torque sensor when the stirring head is in the target depth section, and determining the soil layer type of the target depth section based on the driving torque for destroying each soil layer type when the stirring head is in the target depth section and the actual measurement torque measured by the torque sensor.
Further, the physical and mechanical parameters comprise cohesive force, friction angle, gravity, friction coefficient and lateral pressure coefficient;
the step of calculating the driving torque for damaging each soil layer type when the stirring head is in the target depth section according to the preset calculation rule comprises the following steps:
sequentially selecting a target soil layer type from the multiple soil layer types, and calculating the driving torque of the stirring head for damaging the target soil layer type in the target depth section according to the following formula to obtain the driving torque of the stirring head for damaging each soil layer type in the target depth section:
M drive the ＝M 1 +M 2 +M 3 (4)
In the formula, M 2 The friction torque of soil and the drill rod, d is the diameter of the drill rod, n' is the number of layers of the overburden layer above the target depth section, and sigma zi The vertical effective stress k of the soil body of the soil layer covering the ith layer si Is the lateral pressure coefficient of the soil of the overburden layer on the ith layer, mu si The friction coefficient h between the soil of the soil layer covering the ith layer and the drill rod i Thickness of the topsoil layer of the i-th layer, c u Shear strength, c cohesive strength of the target soil layer type,
friction angle for target soil type, σ overburden pressure above target depth section, M 3 Is the torque between the stirring head and the soil, l 1 Length of cutting blade, B 1 Width of cutting blade, theta 1 For the angle of inclination of the cutting blade, V Through tube For the head descent speed, n for the head rotation speed, S t For soil sensitivity, k is the number of leaf layers, l 2 Is the length of the blade, B 2 Is the width of the blade, theta 2 As angle of inclination of the blades, M Drive the Drive torque, M, for driving the drill rod by the power head 1 And the friction torque corresponding to the target depth section.
Further, the derivation process of equation (3) is as follows:
according to the principle of a cross plate shear test, the method comprises the following steps:
in formula (II) to' 1 For overcoming the moment, M ', required for the shear strength of the cylindrical soil mass' 2 The moment required for overcoming the shear strength of the top surface soil body and the bottom surface soil body, M is the total moment for overcoming the shear strength of the soil body, d is the diameter of a drill rod, l is the length of a blade or the length of a cutting blade, B is the width of the blade or the width of the cutting blade, and theta is the blade inclination angle or the cutting blade inclination angle;
in the construction process, the relation that the cutting blade stirs and destroys the soil body is as follows:
h 1 ＝B 1 sinθ 1 -h 2 (9)
in the formula, h 2 Thickness of undisturbed soil for cutting blade stirring, h 1 Thickness of disturbed soil for cutting blade agitation;
substituting equation (8) and equation (9) into equation (7) in consideration of the lowering of the stirring head yields:
in the formula, M Tubular pipe 1 Is the torque of the cutting blade;
calculating the torque of the blade:
in the formula, M Tubular pipe 1 Is the torque of the blade;
the torque between the stirring head and the soil is as follows:
M 3 ＝M tubular pipe 1 +kM Through 2 (12)；
Substituting equation (10) and equation (11) into equation (12) yields:
further, the friction torque between the pile gripper and the drill rod when the stirring head descends to the bottom end of each depth section is obtained, and the step of obtaining the friction torque corresponding to each depth section comprises the following steps:
determining a test point in the construction area, and determining the actual soil layer distribution in the design construction depth range below the test point to obtain the actual soil layer type corresponding to each depth section;
constructing the test points through the stirring assembly, and recording the depth section where the stirring head is located as a target depth section when the stirring head descends to the bottom end of each depth section;
based on physical and mechanical parameters of an actual soil layer type, calculating friction torque between soil and a drill rod when a stirring head descends to a target depth section according to a formula (1), and calculating torque between the stirring head and the soil when the stirring head descends to the target depth section according to a formula (2) and a formula (3);
acquiring an actual measurement torque measured by a torque sensor when the stirring head descends to a target depth section;
calculating friction torque corresponding to the target depth section according to a formula (4) based on the actually measured torque, the friction torque of the soil and the drill rod obtained through calculation and the torque between the stirring head and the soil;
and obtaining the friction torque corresponding to each depth section based on the friction torque corresponding to the target depth sections.
Compared with the prior art, the invention has the beneficial effects that:
(1) in the construction process, driving torques required by the stirring head to damage different soil layers are calculated layer by layer from top to bottom, soil layer types corresponding to different depths are sequentially identified according to actual measurement torques measured by the torque sensor, and the accuracy of soil layer type judgment is improved;
(2) the method provides soil layer type division data for the targeted construction of each mixing pile, provides a basis for adjusting process parameters of each mixing pile, and can effectively improve the uniformity of the whole mixing pile and reduce the construction cost.
Drawings
FIG. 1 is a flow chart illustrating the steps of the method for identifying a soil layer of a cement mixing pile based on output torque according to the present invention;
fig. 2 is a schematic structural diagram of a stirring assembly in the output torque-based cement stirring pile soil layer identification method.
In the figure, 1-pile gripper, 2-drill rod, 3-power head, 4-stirring head, 5-blade, 6-cutting blade and 7-torque sensor.
Detailed Description
In order to make the objects, technical solutions and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are some, but not all, embodiments of the present invention. The components of embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations.
Thus, the following detailed description of the embodiments of the present invention, presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.
It should be noted that: like reference numbers and letters refer to like items in the following figures, and thus, once an item is defined in one figure, it need not be further defined and explained in subsequent figures. Meanwhile, in the description of the present invention, the terms "first", "second", and the like are used only for distinguishing the description, and are not construed as indicating or implying relative importance.
It is noted that, herein, relational terms such as first and second, and the like may be used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual 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 may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.
In the description of the present invention, it should be noted that the terms "upper", "lower", "inside", "outside", and the like indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings or orientations or positional relationships conventionally put in use of products of the present invention, and are only for convenience of description and simplification of description, but do not indicate or imply that the devices or elements referred to must have specific orientations, be constructed in specific orientations, and be operated, and thus, should not be construed as limiting the present invention.
Referring to fig. 2, fig. 2 is a schematic structural diagram of a stirring assembly in the output torque-based cement stirring pile soil layer identification method of the present invention. The utility model provides a cement mixing pile soil horizon identification method based on output torque, including the stirring subassembly, the stirring subassembly includes the pile gripper, set up many drilling rods on the pile gripper and be connected with many drilling rods and be used for the rotatory unit head of drive drilling, the bottom of drilling rod is equipped with the stirring head, be equipped with the multilayer blade on the stirring head lateral wall, the stirring head bottom is equipped with cutting blade, still include intelligent terminal, be equipped with the torque sensor who is used for measuring the drilling rod moment of torsion between, intelligent terminal is connected with torque sensor.
Referring to fig. 1, fig. 1 is a flowchart illustrating steps of a method for identifying a soil layer of a cement mixing pile based on an output torque according to the present invention. The invention relates to a cement mixing pile soil layer identification method based on output torque, which comprises the following steps:
s1, surveying the construction area, determining various soil layer types contained in the construction area, and acquiring physical and mechanical parameters of each soil layer type;
s2, obtaining a design construction depth, and dividing the design construction depth into a plurality of depth sections;
s3, before construction, acquiring friction torque between the pile gripper and the drill rod when the stirring head descends to the bottom end of each depth section, and acquiring the friction torque corresponding to each depth section;
s4, in the construction process, when the stirring head descends to the bottom end of each depth section, recording the depth section where the stirring head is located as a target depth section, and calculating the driving torque for damaging each soil layer type when the stirring head is at the target depth section according to preset calculation rules based on the physical and mechanical parameters of each soil layer type and the friction torque corresponding to the target depth section;
and S5, acquiring the measured torque measured by the torque sensor when the stirring head is in the target depth section, and determining the soil layer type of the target depth section based on the driving torque for damaging each soil layer type when the stirring head is in the target depth section and the measured torque measured by the torque sensor.
In step S1, the soil layer distribution in the construction area is surveyed by a drilling survey method, several soil layer types in the construction area are determined to obtain multiple soil layer types included in the construction area, and then the physical mechanical parameters of each soil layer type are tested to obtain the physical mechanical parameters corresponding to each soil layer type.
In the step S2, the design construction depth is the length of the mixing pile, the design construction depth is divided into a plurality of depth sections, the setting of the depth sections can be determined according to the required identification precision, generally, soil layers smaller than 0.5 m in the geotechnical investigation are not divided into soil layer types alone, that is, even if there are two different soils within the range of 0.5 m, the soil layers are treated as one soil layer type in practical application, so the depth sections should not be smaller than 0.5 m. In this embodiment, the depth segment is taken to be 0.5 meters.
In the step S3, the pile gripper controls the drill rod to be vertical, and there is a friction force between the drill rod and the pile gripper, which is mainly influenced by the degree of tightness and the rotational speed, and the degree of tightness and the rotational speed are not greatly changed during the construction process, so that the friction torque between the pile gripper and the drill rod can be processed according to different depths. Before soil layer identification, friction torque between the pile gripper and the drill rod when the stirring head descends to the bottom end of each depth section is acquired for subsequent calculation.
Further, the physical and mechanical parameters include cohesion, friction angle, gravity, friction coefficient and lateral pressure coefficient, and in step S3, the step of obtaining the friction torque between the pile gripper and the drill rod when the stirring head descends to the bottom end of each depth section includes:
s31, determining a test point in the construction area, and determining the actual soil layer distribution in the design construction depth range below the test point to obtain the actual soil layer type corresponding to each depth section;
s32, constructing the test points through the stirring assembly, and recording the depth section where the stirring head is located as a target depth section when the stirring head descends to the bottom end of each depth section;
s33, based on physical and mechanical parameters of the actual soil layer type, calculating the friction torque between the soil and the drill rod when the stirring head descends to the target depth section according to a formula (1), and calculating the torque between the stirring head and the soil when the stirring head descends to the target depth section according to a formula (2) and a formula (3);
s34, acquiring an actually measured torque measured by the torque sensor when the stirring head descends to a target depth section;
s35, calculating friction torque corresponding to the target depth section according to a formula (4) based on the actually measured torque, the friction torque between the soil and the drill rod and the torque between the stirring head and the soil;
and S36, obtaining the friction torque corresponding to each depth section based on the friction torque corresponding to the target depth sections.
In the step S31, since it is determined in the construction area that there are several soil layer types in the construction area by the drilling reconnaissance method in the step S1, the test point may select a drilling position of the drilling reconnaissance method, and therefore, the actual soil layer types corresponding to each depth section below the test point may be obtained by taking out soil samples at different depths of the test point by the reconnaissance hole, that is, dividing the actual soil layer distribution at the test point.
In the step S32, the test point is constructed by using the stirring assembly, and the depth segments are numbered according to the sequence of the depths, for example, when the stirring head descends to 0.5 meter below the ground, that is, when the stirring head descends to the bottom end of the first depth segment, the first depth segment is recorded as the target depth segment, then the stirring head continues descending to 1 meter below the ground, that is, the stirring head descends to the bottom end of the second depth segment, and the second depth segment is recorded as the target depth segment, so that the depth segments are sequentially recorded as the target depth segments by the continuous descending of the stirring head.
In the step S33, since the actual soil layer distribution within the designed construction depth range below the test point is known, when the stirring head descends to the bottom end of the target depth section, the number of the overburden layers above the target depth section can be known from the actual soil layer distribution, and the vertical effective stress σ of the soil body of each overburden layer can be known zi Lateral pressure coefficient mu of earth si Thickness h of the soil i And the diameter d of the drill rod can be directly measured, thus according to the formula (1)
Calculating the friction torque M of the soil and the drill rod when the stirring head descends to the target depth section 2 . And similarly, obtaining the overburden pressure sigma above the target depth section according to the number of the overburden above the target depth section, the actual soil type of each overburden, the thickness of each overburden and the gravity of each overburden, wherein if the construction area is below the water surface, the overburden pressure sigma above the target depth section is added with the water pressure, and the water pressure is equal to the gravity of the water multiplied by the depth of the water. Specifically, taking the construction area below the water surface as an example, the overburden pressure σ above the target depth section is calculated by the following formula:
in the formula, gamma Water (W) Is the gravity of water, h Water (W) Is the depth of water, n' is the number of overburden layers above the target depth section, gamma Soil i Is the weight of the topsoil layer on the ith layer, h Soil i The thickness of the overburden layer on the ith layer is shown, wherein i is 1, 2, … … and n'.
The cohesive force c and the friction angle can be obtained according to the actual soil layer type corresponding to the target depth section
Thus according to formula (2)
Calculating the shear strength of the actual soil type corresponding to the target depth section when the stirring head descends to the target depth section, calculating the soil sensitivity of the actual soil type corresponding to the target depth section according to the formula (3) by combining the sizes and the number of layers of the cutting blade and the blade on the stirring head
Calculating the torque M between the actual soil layer type soils corresponding to the stirring head and the target depth section when the stirring head descends to the target depth section 3 。
In step S34, an actually measured torque measured by the torque sensor is obtained, where the actually measured torque is a driving torque required by the power head to drive the drill rod to rotate when the stirring head descends to the target depth section.
In the above step S35, formula (4) M Drive the ＝M 1 +M 2 +M 3 Variation to give M 1 ＝M Drive the -M 2 -M 3 The driving torque M obtained in step S34 Drive the And the soil obtained in step S33Friction torque M of drill rod 2 And the torque M between the stirring head and the soil layer 3 Substituting to obtain the friction torque between the pile gripper and the drill rod when the stirring head descends to the target depth section, and obtaining the friction torque M corresponding to the target depth section 1 。
In the step S36, the mixer head is lowered to the design construction depth, and the friction torques corresponding to the plurality of target depth steps, i.e., the friction torques corresponding to the respective depth steps, are sequentially calculated and obtained from the steps S33 to S35.
In the step S4, the depth segments are numbered according to the depth, and in the construction process, if the stirring head descends to 0.5 meter below the ground, that is, the stirring head descends to the bottom end of the first depth segment, the first depth segment is recorded as the target depth segment, then the stirring head descends to 1 meter below the ground, that is, the stirring head descends to the bottom end of the second depth segment, and the second depth segment is recorded as the target depth segment, so that the depth segments are sequentially recorded as the target depth segments by the continuous descending of the stirring head. And then calculating the driving torque for damaging each soil layer type when the stirring head is in the target depth section according to a preset calculation rule based on the physical and mechanical parameters of each soil layer type and the friction torque corresponding to the target depth section.
Further, in step S4, the physical-mechanical parameters include cohesion, friction angle, weight, friction coefficient, and lateral pressure coefficient;
the step of calculating the driving torque for damaging each soil layer type when the stirring head is in the target depth section according to the preset calculation rule comprises the following steps:
s41, sequentially selecting a target soil layer type from the multiple soil layer types, and calculating the driving torque of the stirring head for damaging the target soil layer type in the target depth section according to the following formula to obtain the driving torque of the stirring head for damaging each soil layer type in the target depth section:
M drive the ＝M 1 +M 2 +M 3 (4)
In the formula, M 2 The friction torque of soil and the drill rod, d is the diameter of the drill rod, n' is the number of layers of the overburden layer above the target depth section, and sigma zi The vertical effective stress k of the soil body of the soil layer covering the ith layer si Is the lateral pressure coefficient of the soil of the overburden layer on the ith layer, mu si The friction coefficient h between the soil of the soil layer covering the ith layer and the drill rod i Thickness of the topsoil layer of the i-th layer, c u Shear strength, c cohesive strength of the target soil layer type,
friction angle for target soil type, σ overburden pressure above target depth section, M 3 Is the torque between the stirring head and the soil, l 1 Length of cutting blade, B 1 Is the width of the cutting blade, θ 1 For the angle of inclination of the cutting blade, V Through tube For the head descent speed, n for the head rotation speed, S t For soil sensitivity, k is the number of leaf layers, l 2 Is the length of the blade, B 2 Is the width of the blade, theta 2 As angle of inclination of the blades, M Drive the Drive torque, M, for driving the drill rod by the power head 1 And the friction torque corresponding to the target depth section.
In step S41, when the mixing head descends to the target depth section, the soil layer type of the depth section above the target depth section is identified and known, and the soil layer type corresponding to the target depth section is unknown, so that one target soil layer type is selected from the soil layer types, the target soil layer type is assumed as the soil layer type of the target depth section, and the number of soil layer types contacting the drill rod can be determined, andsoil body vertical effective stress sigma for determining types of soil layers of each layer zi Lateral pressure coefficient k of earth si Coefficient of friction mu between soil and drill rod si And thickness of the soil, according to the formula (1)
Calculating to obtain the friction torque M of the soil and the drill rod when the stirring head descends to the target depth section when the soil layer type corresponding to the target depth section is the target soil layer type 2 Similarly, the overburden pressure sigma above the target depth section can be obtained according to the number of the overburden above the target depth section, the soil type of each overburden, the thickness of each overburden and the gravity of each overburden, and the cohesive force c and the friction angle can be obtained according to the target soil type corresponding to the target depth section
Thus according to formula (2)
Calculating the shear strength of the target soil layer type when the stirring head descends to the target depth section, and then calculating the shear strength of the target soil layer type according to the formula (3) by the soil sensitivity of the target soil layer type and combining the size of the cutting blade on the stirring head and the size and the number of layers of the blades on the stirring head
Calculating to obtain the torque M between the stirring head and the soil of the target soil layer type when the soil layer type corresponding to the target depth section is the target soil layer type and the stirring head descends to the target depth section 3 And then according to the friction torque corresponding to the target depth section, obtaining the friction torque M between the pile gripper and the drill rod when the stirring head descends to the target depth section 1 According to the formula (4) M Drive the ＝M 1 +M 2 +M 3 Calculating to obtain a driving torque M for damaging the target soil layer type when the stirring head is at the target depth section Drive the . And assuming a plurality of soil layer types contained in the construction area as the soil layer types of the target depth section in sequence, and obtaining the driving torque for damaging each soil layer type when the stirring head is in the target depth section.
Further, in step S41, the derivation process of equation (3) is as follows:
according to the cross plate shear test principle, the torque can be divided into two parts, one part is used for overcoming the soil shear strength of the side surface formed into a cylindrical surface, and the other part is used for overcoming the soil shear strength of the top surface and the bottom surface formed into a ring, so that the torque is obtained:
in formula (II) to' 1 For overcoming the moment, M ', required for the shear strength of the cylindrical soil mass' 2 The moment required for overcoming the shear strength of the top surface soil body and the bottom surface soil body, M is the total moment for overcoming the shear strength of the soil body, d is the diameter of the drill rod, l is the length of the blade or the length of the cutting blade, B is the width of the blade or the width of the cutting blade, and theta is the blade inclination angle or the cutting blade inclination angle;
in the work progress, in the soil body that cutting blade stirring destroyed, the soil body of cutting blade bottom destruction is original state soil, and when cutting blade upper portion got into the soil body stirring, the soil body was the disturbed soil of stirring through cutting blade bottom, and consequently the relation that cutting blade stirring destroyed the soil body does:
h 1 ＝B 1 sinθ 1 -h 2 (9)
in the formula, h 2 Thickness of undisturbed soil for cutting blade stirring, h 1 Thickness of disturbed soil for cutting blade agitation;
considering the condition that the stirring head descends, mixing 1 And h 2 Substituting into formula (7) and considering the soil sensitivity after soil layer construction disturbance to obtain:
substituting equation (8) and equation (9) into equation (13) yields:
in the formula, M Tubular pipe 1 Is the torque of the cutting blade;
the soil body of blade stirring cutting all is the disturbed soil after the cutting blade stirring, consequently need consider the soil body sensitivity after the soil layer construction disturbance, calculates the moment of torsion of blade:
in the formula, M Tubular pipe 1 Is the torque of the blade;
the torque between the stirring head and the soil is as follows:
M 3 ＝M tubular pipe 1 +kM Tubular pipe 2 (12)；
Substituting equation (10) and equation (11) into equation (12) yields:
in step S5, the driving torque of the mixing head that destroys each soil layer type in the target depth segment may obtain a one-to-one correspondence relationship between a plurality of soil layer types and a plurality of driving torques in the target depth segment, and then the torque sensor may obtain an actual measurement torque of the mixing head in the target depth segment, where the actual measurement torque is a torque of the mixing head that drives the drill pipe in the target depth segment, and the actual measurement torque may be compared with the driving torque of the mixing head that destroys each soil layer type in the target depth segment to obtain a driving torque closest to the actual measurement torque, and the soil layer type corresponding to the driving torque closest to the actual measurement torque may be used as the soil layer type in the target depth segment. Therefore, when the stirring head descends to the designed construction depth, the soil layer types of different depth sections can be sequentially confirmed from top to bottom, so that the soil layer types of all the depth sections can be obtained, and the identification of the stirring pile construction soil layer is realized.
Compared with the prior art, the invention has the beneficial effects that:
(1) in the construction process, driving torques required by the stirring head to damage different soil layers are calculated from top to bottom layer by layer, soil layer types corresponding to different depths are sequentially identified according to actual measurement torques measured by the torque sensor, and the accuracy of soil layer type judgment is improved;
(2) the method provides soil layer type division data for the targeted construction of each mixing pile, provides a basis for adjusting process parameters of each mixing pile, and can effectively improve the uniformity of the whole mixing pile and reduce the construction cost.
The above description is only a preferred embodiment of the present invention, and is not intended to limit the present invention in any way, so that any simple modification, equivalent change and modification made to the above embodiment according to the technical spirit of the present invention will still fall within the scope of the technical solution of the present invention without departing from the content of the technical solution of the present invention.
Claims (4)
1. The cement mixing pile soil layer identification method based on the output torque is characterized by comprising a mixing assembly, wherein the mixing assembly comprises a pile embracing device, a plurality of drill rods arranged on the pile embracing device and a power head connected with the drill rods and used for driving a drill hole to rotate, a mixing head is arranged at the bottom end of each drill rod, a plurality of layers of blades are arranged on the outer side wall of the mixing head, and a cutting blade is arranged at the bottom end of the mixing head;
the method comprises the following steps:
surveying a construction area, determining a plurality of soil layer types contained in the construction area, and acquiring physical and mechanical parameters of each soil layer type;
obtaining a design construction depth, and dividing the design construction depth into a plurality of depth sections;
before construction, acquiring friction torque between the pile gripper and a drill rod when the stirring head descends to the bottom end of each depth section, and acquiring the friction torque corresponding to each depth section;
in the construction process, when the stirring head descends to the bottom end of each depth section, recording the depth section where the stirring head is located as a target depth section, and calculating the driving torque of the stirring head damaging each soil layer type in the target depth section according to a preset calculation rule based on the physical and mechanical parameters of each soil layer type and the friction torque corresponding to the target depth section;
and acquiring the actual measurement torque measured by the torque sensor when the stirring head is in the target depth section, and determining the soil layer type of the target depth section based on the driving torque for destroying each soil layer type when the stirring head is in the target depth section and the actual measurement torque measured by the torque sensor.
2. The output torque-based cement mixing pile soil layer identification method according to claim 1, wherein the physical mechanical parameters comprise cohesion, friction angle, weight, friction coefficient and lateral pressure coefficient;
the step of calculating the driving torque for damaging each soil layer type when the stirring head is at the target depth section according to a preset calculation rule comprises the following steps:
sequentially selecting a target soil layer type from the multiple soil layer types, and calculating the driving torque of the stirring head for damaging the target soil layer type in the target depth section according to the following formula to obtain the driving torque of the stirring head for damaging each soil layer type in the target depth section:
M drive the ＝M 1 +M 2 +M 3 (4)
In the formula, M 2 The friction torque of soil and the drill rod, d is the diameter of the drill rod, n' is the number of layers of the overburden layer above the target depth section, and sigma zi The vertical effective stress k of the soil body of the soil layer covering the ith layer si Is the lateral pressure coefficient of the soil of the overburden layer on the ith layer, mu si The friction coefficient h between the soil of the soil layer covering the ith layer and the drill rod i Thickness of the topsoil layer of the i-th layer, c u Shear strength, c cohesive strength of the target soil layer type,
friction angle for target soil type, σ overburden pressure above target depth section, M 3 For the torque between the stirring head and the soil,/ 1 Length of cutting blade, B 1 Width of cutting blade, theta 1 For the angle of inclination of the cutting blade, V Through tube For the head descent speed, n for the head rotation speed, S t For soil sensitivity, k is the number of leaf layers, l 2 Is the length of the blade, B 2 Is the width of the blade, theta 2 As angle of inclination of the blades, M Drive the Drive torque, M, for driving the drill rod by the power head 1 And the friction torque corresponding to the target depth section.
3. The output torque-based cement mixing pile-soil layer identification method according to claim 2, wherein the derivation process of the formula (3) is as follows:
according to the principle of a cross plate shear test, the method comprises the following steps:
in formula (II) to' 1 For overcoming the moment, M ', required for the shear strength of the cylindrical soil mass' 2 The moment required for overcoming the shear strength of the top surface soil body and the bottom surface soil body, M is the total moment for overcoming the shear strength of the soil body, d is the diameter of the drill rod, l is the length of the blade or the length of the cutting blade, B is the width of the blade or the width of the cutting blade, and theta is the blade inclination angle or the cutting blade inclination angle;
in the construction process, the relation that the cutting blade stirs and destroys the soil body is:
h 1 ＝B 1 sinθ 1 -h 2 (9)
in the formula, h 2 Thickness of undisturbed soil for cutting blade stirring, h 1 Thickness of disturbed soil for cutting blade agitation;
substituting equation (8) and equation (9) into equation (7) in consideration of the lowering of the stirring head yields:
in the formula, M Tubular pipe 1 Is the torque of the cutting blade;
calculating the torque of the blade:
in the formula, M Tubular pipe 1 Is the torque of the blade;
the torque between the stirring head and the soil is as follows:
M 3 ＝M tubular pipe 1 +kM Tubular pipe 2 (12)；
Substituting equation (10) and equation (11) into equation (12) yields:
4. the method for identifying the soil layer of the cement mixing pile based on the output torque as claimed in claim 2, wherein the step of obtaining the friction torque between the pile gripper and the drill rod when the mixing head descends to the bottom end of each depth section to obtain the friction torque corresponding to each depth section comprises:
determining a test point in the construction area, and determining the actual soil layer distribution in the design construction depth range below the test point to obtain the actual soil layer type corresponding to each depth section;
constructing a test point through the stirring assembly, and recording the depth section where the stirring head is located as a target depth section when the stirring head descends to the bottom end of each depth section;
based on physical and mechanical parameters of an actual soil layer type, calculating the friction torque between soil and a drill rod when the stirring head descends to a target depth section according to a formula (1), and calculating the torque between the stirring head and the soil when the stirring head descends to the target depth section according to a formula (2) and a formula (3);
acquiring an actual measurement torque measured by a torque sensor when the stirring head descends to a target depth section;
calculating friction torque corresponding to the target depth section according to a formula (4) based on the actually measured torque, the friction torque between the soil and the drill rod obtained through calculation and the torque between the stirring head and the soil;
and obtaining the friction torque corresponding to each depth section based on the friction torque corresponding to the target depth sections.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210569014.XA CN114855748B (en) | 2022-05-24 | 2022-05-24 | Output torque-based cement mixing pile soil layer identification method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| CN202210569014.XA CN114855748B (en) | 2022-05-24 | 2022-05-24 | Output torque-based cement mixing pile soil layer identification method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| CN114855748A true CN114855748A (en) | 2022-08-05 |
| CN114855748B CN114855748B (en) | 2023-04-07 |
Family
ID=82639117
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CN202210569014.XA Active CN114855748B (en) | 2022-05-24 | 2022-05-24 | Output torque-based cement mixing pile soil layer identification method |
Country Status (1)
| Country | Link |
|---|---|
| CN (1) | CN114855748B (en) |
Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104866664A (en) * | 2015-05-19 | 2015-08-26 | 上海市建工设计研究院有限公司 | Method for predicting construction difficulty of water seepage prevention curtain-grouting |
| CN111022097A (en) * | 2019-12-12 | 2020-04-17 | 河海大学 | Construction method of spiral anchor and cement mixing pile construction all-in-one machine |
| CN111178741A (en) * | 2019-12-25 | 2020-05-19 | 德清县杭绕高速有限公司 | Mixing pile quality evaluation method based on construction remote monitoring system |
| CN111259467A (en) * | 2020-01-09 | 2020-06-09 | 广东省交通规划设计研究院股份有限公司 | Method and device for identifying overall stability of foundation pit and computer equipment |
| CN111680341A (en) * | 2020-04-10 | 2020-09-18 | 中国能源建设集团浙江省电力设计院有限公司 | Bearing capacity analysis method for pre-drilled pile sinking pile foundation in dam region |
| CN112883657A (en) * | 2021-01-13 | 2021-06-01 | 中国长江三峡集团有限公司 | Single-pile vertical bearing time-varying effect calculation method considering soil body non-Darcy consolidation |
| CN113128061A (en) * | 2021-04-25 | 2021-07-16 | 交通运输部公路科学研究所 | Soil pressure acquisition method for adjacent underground engineering asynchronous construction |
| CN113128094A (en) * | 2021-04-25 | 2021-07-16 | 交通运输部公路科学研究所 | Limited soil mass soil pressure acquisition method considering septal soil width in adjacent underground engineering |
| CN113846707A (en) * | 2021-09-29 | 2021-12-28 | 北京中岩大地科技股份有限公司 | Method for predicting side resistance of mixing pile under consideration of multi-factor influence |
| CN114036625A (en) * | 2021-12-09 | 2022-02-11 | 中冶建筑研究总院（深圳）有限公司 | Intelligent construction method and system suitable for in-situ reinforcement of large-area soft foundation |
| CN114091164A (en) * | 2021-11-29 | 2022-02-25 | 上海隧道工程有限公司 | Method for judging local stability of water-rich soft soil stratum |
| CN114297950A (en) * | 2021-11-24 | 2022-04-08 | 淮北矿业股份有限公司 | Method for calculating distribution of water loss compression amount of pressure-bearing water-containing loose layer region |
| CN114329953A (en) * | 2021-12-27 | 2022-04-12 | 中建铁路投资建设集团有限公司 | Method for judging whether screw pile enters bearing stratum or not |
-
2022
- 2022-05-24 CN CN202210569014.XA patent/CN114855748B/en active Active
Patent Citations (13)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN104866664A (en) * | 2015-05-19 | 2015-08-26 | 上海市建工设计研究院有限公司 | Method for predicting construction difficulty of water seepage prevention curtain-grouting |
| CN111022097A (en) * | 2019-12-12 | 2020-04-17 | 河海大学 | Construction method of spiral anchor and cement mixing pile construction all-in-one machine |
| CN111178741A (en) * | 2019-12-25 | 2020-05-19 | 德清县杭绕高速有限公司 | Mixing pile quality evaluation method based on construction remote monitoring system |
| CN111259467A (en) * | 2020-01-09 | 2020-06-09 | 广东省交通规划设计研究院股份有限公司 | Method and device for identifying overall stability of foundation pit and computer equipment |
| CN111680341A (en) * | 2020-04-10 | 2020-09-18 | 中国能源建设集团浙江省电力设计院有限公司 | Bearing capacity analysis method for pre-drilled pile sinking pile foundation in dam region |
| CN112883657A (en) * | 2021-01-13 | 2021-06-01 | 中国长江三峡集团有限公司 | Single-pile vertical bearing time-varying effect calculation method considering soil body non-Darcy consolidation |
| CN113128061A (en) * | 2021-04-25 | 2021-07-16 | 交通运输部公路科学研究所 | Soil pressure acquisition method for adjacent underground engineering asynchronous construction |
| CN113128094A (en) * | 2021-04-25 | 2021-07-16 | 交通运输部公路科学研究所 | Limited soil mass soil pressure acquisition method considering septal soil width in adjacent underground engineering |
| CN113846707A (en) * | 2021-09-29 | 2021-12-28 | 北京中岩大地科技股份有限公司 | Method for predicting side resistance of mixing pile under consideration of multi-factor influence |
| CN114297950A (en) * | 2021-11-24 | 2022-04-08 | 淮北矿业股份有限公司 | Method for calculating distribution of water loss compression amount of pressure-bearing water-containing loose layer region |
| CN114091164A (en) * | 2021-11-29 | 2022-02-25 | 上海隧道工程有限公司 | Method for judging local stability of water-rich soft soil stratum |
| CN114036625A (en) * | 2021-12-09 | 2022-02-11 | 中冶建筑研究总院（深圳）有限公司 | Intelligent construction method and system suitable for in-situ reinforcement of large-area soft foundation |
| CN114329953A (en) * | 2021-12-27 | 2022-04-12 | 中建铁路投资建设集团有限公司 | Method for judging whether screw pile enters bearing stratum or not |
Also Published As
| Publication number | Publication date |
|---|---|
| CN114855748B (en) | 2023-04-07 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| Skempton | Vane tests in the alluvial plain of the River Forth near Grangemouth | |
| CN103649781B (en) | Azimuthal brittleness logging systems and methods | |
| Robertson | In-situ testing of soil with emphasis on its application to liquefaction assessment | |
| CN115033973B (en) | Method for calculating side pressure of soil between piles and piles of double-row piles of foundation pit based on natural source surface waves | |
| CN107102378A (en) | The method that artesian aquifer water level and head height are determined using hole pressure touching methods | |
| CN114880747B (en) | Cement mixing pile soil layer identification method based on mixing energy consumption | |
| Di Buò | Evaluation of the Preconsolidation Stress and Deformation Characteristics of Finnish Clays based on Piezocone Testing | |
| CN114855748B (en) | Output torque-based cement mixing pile soil layer identification method | |
| EP2101195B1 (en) | Method and apparatus for determining formation and fluid properties | |
| JP6153591B2 (en) | Ground survey method and ground survey device | |
| CN116988786A (en) | Three-dimensional ground stress measuring method for underground mine | |
| JPS63156110A (en) | Foundation examining method | |
| Emdal et al. | Characterisation of quick clay at Dragvoll, Trondheim, Norway | |
| CN114855749B (en) | Pressure-based mixing pile soil layer identification method | |
| KR100777377B1 (en) | Automatic Control System for Insert Limit of Casing Pipe In Soft Ground Improvement and Method thereof | |
| Hannigan et al. | Advances in quality control methods for bored pile and diaphragm wall foundations with case histories | |
| Cai et al. | Comparative performance of the international piezocone and China CPT in Jiangsu Quaternary clays of China | |
| Zotsenko | Improvement of the investigation of physical and mechanical characteristics of sedimentary rocks by express methods | |
| Baez et al. | Assessment of soil strength using a robotically deployed and retrieved penetrometer | |
| Kurtulus | Field measurements of the linear and nonlinear shear moduli of soils using drilled shafts as dynamic cylindrical sources | |
| Hebeler et al. | A multi piezo friction attachment for penetration testing | |
| Acworth | Measurement of vertical environmental-head profiles in unconfined sand aquifers using a multi-channel manometer board | |
| Wei et al. | Field testing of inclined cone penetration | |
| KR200396374Y1 (en) | Automatic Control System for Insert Limit of Casing Pipe In Soft Ground Improvement | |
| Benson et al. | A summary of methods for locating and mapping fractures and cavities with emphasis on geophysical methods |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| PB01 | Publication | ||
| PB01 | Publication | ||
| SE01 | Entry into force of request for substantive examination | ||
| SE01 | Entry into force of request for substantive examination | ||
| GR01 | Patent grant | ||
| GR01 | Patent grant |