Analysis and calculation method and device for jacking force of vertical curve pipe jacking

Abstract

The present invention discloses an analysis and calculation method and device for the jacking force of vertical curve pipe jacking. The calculation result is more accurate, reducing the dependence on empirical values; it supplements the calculation of the jacking force for small-diameter and small-axis-radius curve pipe jacking; it can realize the real-time adjustment of the jacking force calculation, providing a reference for intelligent and automated construction; when the axis radius is small, there is no value for the additional friction coefficient in the existing specifications. Compared with the calculation in the existing specifications, the method of partial contact between the pipe and the soil is used to calculate the jacking force, starting from the machine head as the analysis starting point, weakening the error of different earth pressure calculation methods on the calculation of the jacking force of curve pipe jacking. The empirical parameters are few and the value range is small, making the calculation result closer to the actual situation. The main parameters of this calculation method are the earth pressure of the machine head and the contact pressure between the pipe and the slurry, and these two data can be transmitted in real time through the setting of stress gauge sensors to realize the automatic adjustment of the jacking force calculation.

Description

Technical Field

[0001] The present invention belongs to the field of vertical curve pipe jacking, and particularly relates to an analysis and calculation method and device for the jacking force of vertical curve pipe jacking. Background Technique

[0002] With the development of urban construction and maintenance, the pipe jacking technology is increasingly widely used in pipeline laying and maintenance, and the curve pipe jacking technology is also required in the complex urban underground space construction environment. The vertical curve pipe jacking technology has good adaptability and can meet the needs of urban complex underground space construction, such as the construction of mined subway stations in bustling urban areas, the bifurcation and widening construction in shield tunnel construction, the excavation of variable-section tunnels, and the expansion construction of existing underground structures. It is the key research object for future urban underground environment development. For the pipe jacking technology, the calculation of the jacking force is the basis for equipment research and development and construction. In the existing domestic specifications, the calculation of the jacking force of curve pipe jacking generally adopts the method of multiplying the jacking force of straight pipe jacking by an empirical coefficient to determine, and the calculation result deviates greatly from the actual monitoring data of the engineering jacking force. The vertical curve pipe jacking refers to the curve pipe jacking in which the design axis of the pipe jacking only changes in the vertical direction, and the calculation of its jacking force has not been seen in the relevant specifications. The jacking force of the pipe jacking is mainly composed of two parts: the head-on resistance of the pipe jacking machine and the frictional resistance between the pipe joints and the soil. For the calculation of the jacking force of vertical curve pipe jacking, many factors such as the contact angle between the pipe joint and the soil, the soil pressure on the pipe joint, and the soil layer properties will affect the accuracy of the jacking force calculation.

[0003] For vertical curve pipe jacking, the frictional resistance between the pipe and the soil is much greater than the head-on resistance of the machine head, and the calculation difficulty of the pipe-soil frictional resistance is much greater than that of the head-on resistance of the machine head. Taking the force on the head of the vertical curve pipe jacking as the basis for calculating the jacking force, in the force transmission process, the forces between the machine head and the pipe joints and between the pipe joints are transmitted along the axial direction of the pipe joints. Therefore, there is a lateral component force perpendicular to the axis of the pipe joint, which causes the pipe joint to contact the hole wall outside the trajectory curve, and then generates additional frictional resistance. Combining the existing research and the actual construction of the pipe jacking project, a jacking force calculation model applicable to vertical curve pipe jacking is established, which is easy to program and the calculation result is also in line with the engineering practice.

[0004] The deficiencies of the existing specifications for the calculation of the jacking force of curve pipe jacking are as follows:

[0005] (1) It gives the empirical values of the frictional resistance for different strata and pipe materials, but the value range is large;

[0006] (2) The specification recommends using the local empirical formula to determine the jacking force, but very few local standards further recommend the calculation method;

[0007] (3) Taking values according to the specification is often significantly larger than the actual value, deviating from the engineering practice, and may cause waste of resources;

[0008] (4) There is some controversy about the degree of reflection of the calculation model adopted by the specification formula on the actual situation. Summary of the Invention

[0009] In order to solve the technical problems existing in the background technology, the present invention aims to provide an analysis and calculation method and device for the jacking force of a vertical curve pipe jacking, which is an innovation in the calculation method of the jacking force of curve pipe jacking, applicable to the calculation of the jacking force of small-radius curve pipe jacking, with a simple formula, easy-to-obtain parameters, and the jacking force can be adjusted in real time through monitoring data, providing a reference for related construction and equipment manufacturing.

[0010] In order to solve the technical problems, the technical solution of the present invention is as follows:

[0011] An analysis and calculation method and device for the jacking force of a vertical curve pipe jacking, the method comprising:

[0012] Conduct a force analysis on the overall structure of the preset vertical curve pipe jacking to obtain the force analysis results of the pipe joints and the force analysis results of the machine head of the curve pipe jacking;

[0013] Obtain the relevant basic parameters of the vertical curve pipe jacking;

[0014] According to the relevant basic parameters of the vertical curve pipe jacking and the force analysis results of the machine head, construct a calculation model for the resistance of the pipe jacking machine head;

[0015] According to the relevant basic parameters of the vertical curve pipe jacking, construct a calculation model for the net buoyancy of the pipe slurry of the first pipe joint;

[0016] According to the relevant basic parameters of the vertical curve pipe jacking, the calculation model for the resistance of the pipe jacking machine head, and the force analysis results of the pipe joints, construct a calculation model for the resistance of the pipe-soil mold of the first pipe joint;

[0017] According to the relevant basic parameters of the vertical curve pipe jacking, construct a calculation model for the frictional resistance of the pipe slurry of a single pipe joint;

[0018] Based on the calculation model for the resistance of the pipe jacking machine head, the calculation model for the net buoyancy of the pipe slurry of the first pipe joint, the calculation model for the frictional resistance of the pipe-soil of the first pipe joint, and the calculation model for the frictional resistance of the pipe slurry of a single pipe joint, construct a calculation model for the jacking force of the curve pipe jacking, that is, the analysis and calculation of the jacking force of the vertical curve pipe jacking are realized.

[0019] Further, the construction of the calculation model for the resistance of the pipe jacking machine head specifically includes: constructing a calculation model for the frontal resistance of the pipe jacking machine head and a calculation model for the frictional resistance on the outer wall of the pipe jacking machine head, and summing the calculation model for the frontal resistance of the pipe jacking machine head and the calculation model for the frictional resistance on the outer wall of the pipe jacking machine head to obtain the calculation model for the resistance of the pipe jacking machine head F0.

[0020] Further, the construction of the calculation model for the frontal resistance of the pipe jacking machine head specifically includes:

[0021]

[0022] Where: p0 is the static earth pressure at the pipe jacking machine head, and the Rankine static earth pressure is adopted, p0 = K0γz, where K0 is the Rankine static earth pressure coefficient. γ is the unit weight of soil in kN / m 3 , and the effective unit weight is adopted below the groundwater level; is the internal friction angle of soil; z is the buried depth of the calculation point measured from the ground surface, in m.

[0023] Furthermore, the construction of the calculation model for the frictional resistance on the outer wall of the pipe jacking machine head specifically includes:

[0024] f0 = μN0;

[0025] Where: μ is the pipe-soil friction coefficient, and the value range is 0.2 - 0.4; N0 is the resultant force of the earth pressure on the outer wall of the machine head. For deeply buried pipelines, the Marston method considering the soil arch effect is used for calculation:

[0026]

[0027]

[0028] For shallowly buried pipelines, the soil column theory is used for calculation:

[0029]

[0030]

[0031] Where: K is the lateral earth pressure coefficient, taking 1.0; K a is the active earth pressure coefficient; h' is the buried depth of the midpoint of the machine head; B e is the width of the disturbed soil; γ is the unit weight of soil; c is the cohesion of the soil mass; is the internal friction angle of the soil mass; N0 is the earth pressure on the machine head; L' is the length of the machine head.

[0032] Furthermore, the construction of the calculation model for the net buoyancy of the pipe grout of the first pipe section specifically includes:

[0033]

[0034] Where: γ s is the unit weight of the grouting slurry (kN / m3); G g is the weight of the pipe section (kN).

[0035] Furthermore, the construction of the calculation model for the pipe-soil frictional resistance of the first pipe section specifically includes:

[0036]

[0037] Where: μ is the pipe-soil friction coefficient, with a value range of 0.1 to 0.3; θ is half of the rotation angle generated by a single pipe section at the center of the circle. If the designed axis rotation angle is α and it consists of n pipe sections, then θ = α / 2n.

[0038] Furthermore, the construction of the calculation model for the pipe-grout frictional resistance of a single pipe section specifically includes:

[0039]

[0040] Where: L' is the length of a single pipe section; D is the outer diameter of the pipe section; f′ k is the pipe-grout frictional resistance per unit area, taking a value of 0.3 - 0.5 kPa. A smaller value is taken when the radius of the central axis of the stable formation is large and the construction technology is mature, and a larger value is taken when the construction difficulty is greater and the axis radius is small in the complex formation.

[0041] Furthermore, the construction of the calculation model for the jacking force of the vertical curve pipe jacking specifically includes:

[0042]

[0043] Among them, F n+1 represents the jacking force of the (n + 1)-th pipe section on the n-th pipe section.

[0044] An analysis and calculation device for the jacking force of the vertical curve pipe jacking, the device includes:

[0045] The force analysis module: used to perform force analysis and processing on the overall structure of the preset vertical curve pipe jacking to obtain the pipe section force analysis result and the head force analysis result of the curve pipe jacking;

[0046] The acquisition module, used to acquire the relevant basic parameters of the vertical curve pipe jacking;

[0047] The first construction module, used to construct the jacking resistance calculation model of the pipe jacking head according to the relevant basic parameters of the vertical curve pipe jacking and the head force analysis result;

[0048] The second construction module, used to construct the calculation model of the net buoyancy of the pipe grout of the first pipe section according to the relevant basic parameters of the vertical curve pipe jacking;

[0049] The third construction module, used to construct the pipe-soil friction resistance calculation model of the first pipe section according to the relevant basic parameters of the vertical curve pipe jacking, the jacking resistance calculation model of the pipe jacking head, and the pipe section force analysis result;

[0050] The fourth construction module, used to construct the calculation model of the pipe-grout frictional resistance of a single pipe section according to the relevant basic parameters of the vertical curve pipe jacking;

[0051] The fifth construction module is used to construct a jacking force calculation model for curved pipe jacking based on the jacking head resistance calculation model, the net buoyancy of pipe grout of the first pipe section calculation model, the pipe-soil friction force calculation model of the first pipe section, and the pipe grout friction resistance calculation model of a single pipe section, that is, the analysis and calculation of the jacking force of vertical curve pipe jacking are realized.

[0052] Compared with the prior art, the advantages of the present invention are as follows:

[0053] The calculation results are more accurate, reducing the dependence on empirical values; the calculation of the jacking force for small-diameter and small-axis-radius curved pipe jacking is supplemented; the real-time adjustment of the jacking force calculation can be realized, providing a reference for intelligent and automated construction.

[0054] When the axis radius is small, there is no value for the additional friction coefficient in the specification. Compared with the existing specification calculation, the method of calculating the jacking force by using the partial contact of the pipe and soil is adopted, with the jacking head as the analysis starting point, weakening the error of the different earth pressure calculation methods on the jacking force calculation of curved pipe jacking. The empirical parameters are few and the value range is small, making the calculation results closer to the actual situation. The main parameters of this calculation method are the earth pressure of the jacking head and the contact pressure of the pipe grout, and these two data can be transmitted in real time through the stress gauge sensor to realize the automatic adjustment of the jacking force calculation. Brief Description of the Drawings

[0055] Figure 1 Figure is the schematic diagram of the jacking of a vertical curve pipe jacking in the present invention;

[0056] Figure 2 Figure is the schematic diagram of the load distribution of the nth pipe section in the analysis and calculation method and device of the jacking force of a vertical curve pipe jacking in the present invention. Detailed Embodiments

[0057] The following describes the specific embodiments of the present invention in conjunction with the embodiments:

[0058] It should be noted that the structures, ratios, sizes, etc. shown in this specification are only used to cooperate with the content disclosed in the specification for those skilled in the art to understand and read, and are not used to limit the implementation conditions of the present invention. Any modification of the structure, change of the proportional relationship, or adjustment of the size, without affecting the effects that the present invention can produce and the purposes that can be achieved, should still fall within the scope covered by the technical content disclosed in the present invention.

[0059] At the same time, the terms such as "upper", "lower", "left", "right", "middle", and "one" cited in this specification are only for the convenience of description and are not used to limit the implementation scope of the present invention. The change or adjustment of their relative relationships, without substantial change in the technical content, should also be regarded as the scope that the present invention can implement.

[0060] Example:

[0061] The present invention is an innovation in the calculation of the jacking force for the jacking of a curved pipe jacking. The jacking resistance of the pipe jacking head and the pipe joint resistance are calculated separately, and then the jacking force is obtained.

[0062] The object of the present invention is achieved by the following means:

[0063] (1) Force analysis of the pipe joint

[0064] As Figure 1 shown, the vertical curve pipe jacking head and the pipe joints are discretized. The jacking resistance of the head is axially transmitted between the pipe joints. The head load is decomposed along the axial and radial directions of the pipe joints. As Figure 1 shown, starting from the head as the force application point for analysis, the head is subjected to the frontal resistance from the front and the frictional resistance generated by the contact between the outer wall of the pipe joint and the soil and the grouting liquid. The resistance is transmitted along the axis of the pipe joint and is perpendicular to the contact surface between the pipe joints. The resistance is decomposed into two mutually perpendicular forces, one along the axis of the pipe joint and the other perpendicular to the axis of the pipe joint, generating frictional resistance due to extrusion with the soil. The frictional resistance is parallel to the axis of the pipe joint and is transmitted backward in this way.

[0065] (2) Force analysis of the curved pipe jacking head

[0066] Considering the environmental protection requirements, when the earth pressure received by the head face is the static earth pressure, the disturbance to the soil is the smallest. Therefore, the static earth pressure is used to calculate the frontal resistance of the head. The head should have a sealing effect on the slurry and only contact the soil. When jacking, the outer wall is subjected to the earth pressure and generates frictional resistance, as Figure 2 shown.

[0067] (3) Calculation of the pipe joint frictional resistance

[0068] It is assumed that 1 / 3 of the cross-section of the pipeline contacts the soil and 2 / 3 contacts the slurry. When a complete and continuous slurry jacket is formed, the contact pressure between the pipe and the slurry for each pipe can be considered the same. Assuming the same net buoyancy, the pipe joint pipe-slurry frictional resistance is the same.

[0069]

[0070] (4) Calculation of the jacking force for the vertical curve pipe jacking

[0071]

[0072]

[0073]

[0074]

[0075]

[0076] Where: μ is the friction coefficient between the pipe and the soil; θ is half of the angle of rotation of a single pipe joint; F0 is the resistance of the machine head; N 12 is the contact pressure between the pipe and the grout of a single pipe joint; L' is the length of a single pipe joint; f n1 is the frictional resistance between the pipe and the soil of a single pipe joint; f n2 is the frictional resistance between the pipe and the grout of a single pipe joint; f′ k is the average frictional resistance per unit area of the grout; D1 is the outer diameter of the machine head; D is the outer diameter of the pipe joint; p0 is the unit static earth pressure at the machine head; N0 is the earth pressure on the outer wall of the machine head.

[0077] The jacking force calculation of the curve pipe jacking machine is realized through the following steps:

[0078] (1) Calculate the resistance against the front of the pipe jacking machine head

[0079]

[0080] Where: p0 is the static earth pressure at the pipe jacking machine head, and the Rankine static earth pressure is adopted, p0 = K0γz, K0 is the Rankine static earth pressure coefficient, γ is the unit weight of soil in kN / m 3 , and the effective unit weight is adopted below the groundwater level; is the internal friction angle of the soil; z is the buried depth of the calculation point measured from the ground surface, in m.

[0081] (2) Calculate the frictional resistance on the outer wall of the pipe jacking machine head

[0082] f0 = μN0;

[0083] Where: μ is the friction coefficient between the pipe and the soil, and the value range is 0.2 - 0.4; N0 is the resultant force of the earth pressure on the outer wall of the machine head. For deeply buried pipelines, the Marston method considering the soil arch effect is adopted for calculation:

[0084]

[0085]

[0086] For shallow buried pipelines, the earth column theory is adopted for calculation:

[0087]

[0088]

[0089] Where: K is the lateral earth pressure coefficient, taking 1.0; K a is the active earth pressure coefficient; h' is the buried depth at the midpoint of the machine head; B e is the width of the disturbed soil; γ is the unit weight of the soil; c is the cohesion of the soil mass; is the internal friction angle of the soil mass; N0 is the earth pressure on the machine head; L' is the length of the machine head.

[0090] The sum of the head-on resistance and the outer wall frictional resistance of the pipe jacking machine head is the pipe jacking machine head resistance F0, that is:

[0091]

[0092] (3) Calculate the net buoyancy of the grout in the first pipe

[0093]

[0094] In the formula: γ s is the specific weight of the grouting slurry (kN / m3); G g is the weight of the pipe section (kN).

[0095] (4) Calculate the pipe-soil frictional resistance of the first pipe

[0096]

[0097] In the formula: μ is the pipe-soil friction coefficient, and the value range is 0.1 - 0.3; θ is half of the angle formed by a single pipe section at the center of the circle. If the design axis angle is α and it is composed of n pipe sections, then θ = α / 2n.

[0098] (5) Calculate the grout-pipe frictional resistance of a single pipe section

[0099]

[0100] In the formula: L' is the length of a single pipe section; D is the outer diameter of the pipe section; f′ k is the grout-pipe frictional resistance per unit area, taking 0.3 - 0.5 kPa. When the axis radius in the stable stratum is large and the construction technology is mature, a smaller value is taken; when the construction difficulty is greater and the axis radius is small in the complex stratum, a larger value is taken.

[0101] (6) Calculate the jacking force for pipe jacking in a curve

[0102]

[0103]

[0104]

[0105]

[0106] All key data in this jacking force calculation formula can be obtained through monitoring. Sensors can be set at the front and outer wall of the machine head to measure the earth pressure instead of the static earth pressure, so as to calculate the head-on resistance F0, and use the measured grout contact pressure instead of N 12, and the soil friction resistance of the first section of pipe is calculated in combination with the actual head-on resistance of the machine head. Combining the foregoing data, if the actual jacking force does not conform to the calculated jacking force, the pipe-soil friction coefficient or the pipe-grout friction resistance per unit area can be adjusted within the value range; if the two still do not conform after adjustment, it is necessary to consider possible unexpected conditions such as unknown strata or unstable hole walls that may be encountered.

[0107] The preferred embodiments of the present invention have been described in detail above, but the present invention is not limited to the above embodiments. Within the scope of knowledge possessed by those of ordinary skill in the art, various changes can be made without departing from the spirit of the present invention.

[0108] Many other changes and modifications can be made without departing from the concept and scope of the present invention. It should be understood that the present invention is not limited to the specific embodiments, and the scope of the present invention is defined by the appended claims.

Claims

1. A method for analyzing and calculating the jacking force of vertical curve pipe jacking, characterized in that, The method includes: Performing a force analysis on the overall structure of the preset vertical curve pipe jacking to obtain the force analysis results of the pipe segments and the force analysis results of the machine head of the curve pipe jacking; Obtaining the relevant basic parameters of the vertical curve pipe jacking; Constructing a resistance calculation model for the pipe jacking machine head according to the relevant basic parameters of the vertical curve pipe jacking and the force analysis results of the machine head; Constructing a net buoyancy calculation model for the pipe grout of the first pipe segment according to the relevant basic parameters of the vertical curve pipe jacking; Constructing a pipe-soil model resistance calculation model for the first pipe segment according to the relevant basic parameters of the vertical curve pipe jacking, the pipe jacking machine head resistance calculation model and the force analysis results of the pipe segments; Constructing a pipe grout friction resistance calculation model for a single pipe segment according to the relevant basic parameters of the vertical curve pipe jacking; Based on the pipe jacking machine head resistance calculation model, the net buoyancy calculation model for the pipe grout of the first pipe segment, the pipe-soil friction force calculation model for the first pipe segment and the pipe grout friction resistance calculation model for a single pipe segment, constructing a curve pipe jacking jacking force calculation model, that is, realizing the analysis and calculation of the jacking force of the vertical curve pipe jacking; Among them, the construction of the pipe jacking machine head resistance calculation model specifically includes: constructing a head-on resistance calculation model for the pipe jacking machine head and an outer wall friction resistance calculation model for the pipe jacking machine head, and summing the head-on resistance calculation model for the pipe jacking machine head and the outer wall friction resistance calculation model for the pipe jacking machine head to obtain the pipe jacking machine head resistance calculation model F0; Among them, the construction of the pipe-soil model resistance calculation model for the first pipe segment specifically includes: ； Wherein: μ is the pipe-soil friction coefficient, with a value range of 0.1 to 0.3; θ is half of the rotation angle generated by a single pipe joint at the center of the circle. If the design axis rotation angle is α , and it is composed of n pipe joints, then ; Among them, the construction of the pipe grout friction resistance calculation model for a single pipe segment specifically includes: ； In the formula: is the length of a single pipe section; D is the outer diameter of the pipe section; is the frictional resistance of the pipe grout per unit area, taking a value of 0.3 - 0.5 kPa. A smaller value is taken when the radius of the central axis of the stable formation is large and the construction technology is mature, and a larger value is taken when the construction difficulty is high and the axis radius is small in the complex formation; Among them, the construction of the curve pipe jacking jacking force calculation model specifically includes: ； Among them, , represents the jacking force of the (n + 1)-th pipe section on the n-th pipe section.

2. The analysis and calculation method for the jacking force of a vertical curve pipe jacking according to claim 1, characterized in that, The construction of the head-on resistance calculation model for the pipe jacking machine head specifically includes: ； In the formula: is the static earth pressure at the pipe jacking machine head, and the Rankine static earth pressure is adopted. , is the Rankine static earth pressure coefficient. ; is the unit weight of soil in kN / m 3 , and the effective unit weight is adopted below the groundwater level; is the internal friction angle of soil; z is the buried depth of the calculation point measured from the ground surface in m.

3. The analysis and calculation method of the jacking force for vertical curve pipe jacking according to claim 1, wherein, The construction of the outer wall friction resistance calculation model for the pipe jacking machine head specifically includes: ； Where: is the pipe-soil friction coefficient, with a value range of 0.2 to 0.4; N 0 is the resultant force of the soil pressure on the outer wall of the machine head. For deeply buried pipelines, the Marston method considering the soil arch effect is used for calculation: ； ； For shallow-buried pipelines, the earth column theory is used for calculation: ； ； In the formula: is the lateral earth pressure coefficient, taking 1.0; is the active earth pressure coefficient; is the buried depth at the midpoint of the machine head; is the width of the disturbed soil; is the unit weight of soil; is the cohesion of soil; is the angle of internal friction of the soil body; is the earth pressure at the cutter head; is the length of the cutter head.

4. The analysis and calculation method for the jacking force of a vertical curve pipe jacking according to claim 1, characterized in that, The construction of the net buoyancy calculation model for the pipe grout of the first pipe segment specifically includes: ； Where: is the specific weight of the grouting slurry, kN / m3; is the weight of the pipe joint, kN.

5. An analytical calculation device for the jacking force of a vertical curve pipe jacking, characterized in that, The device is used to execute the method according to any one of claims 1-4, and the device includes: A force analysis module: used to perform a force analysis on the overall structure of the preset vertical curve pipe jacking to obtain the force analysis results of the pipe segments and the force analysis results of the machine head of the curve pipe jacking; An acquisition module, used to acquire the relevant basic parameters of the vertical curve pipe jacking; A first construction module, used to construct a pipe jacking machine head resistance calculation model according to the relevant basic parameters of the vertical curve pipe jacking and the force analysis results of the machine head; A second construction module, used to construct a net buoyancy calculation model for the pipe grout of the first pipe segment according to the relevant basic parameters of the vertical curve pipe jacking; A third construction module, used to construct a pipe-soil model resistance calculation model for the first pipe segment according to the relevant basic parameters of the vertical curve pipe jacking, the pipe jacking machine head resistance calculation model and the force analysis results of the pipe segments; A fourth construction module, used to construct a pipe grout friction resistance calculation model for a single pipe segment according to the relevant basic parameters of the vertical curve pipe jacking; A fifth construction module, used to construct a curve pipe jacking jacking force calculation model based on the pipe jacking machine head resistance calculation model, the net buoyancy calculation model for the pipe grout of the first pipe segment, the pipe-soil friction force calculation model for the first pipe segment and the pipe grout friction resistance calculation model for a single pipe segment, that is, realizing the analysis and calculation of the jacking force of the vertical curve pipe jacking.

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