A method for calculating the shear strength of reinforced soil slopes

Abstract

This invention provides a method for calculating the shear strength of reinforced soil slopes, relating to the field of slope engineering technology, where the residual sliding force F of the soil slope is known. n Under the premise of considering the reinforcement of the slope to improve its anti-sliding capacity, the shear strength of the reinforced slope after reinforcement is calculated. Considering the synergistic effect between the reinforcement and the slope, the 120-year long-term design tensile strength R of the reinforcement is introduced. y Vertical spacing S of reinforcement material layout y The vertical spacing S of the reinforcing bars y Within the range, utilizing the 120-year long-term design tensile strength R of the reinforcing steel. y Resisting the remaining downward force F n This invention improves the cohesion of the soil slope by using conventional parameters to calculate the improved cohesion c'. The cohesion c' is then substituted into conventional geotechnical design software to calculate the stability of the reinforced soil slope, overcoming the inherent limitations of existing technologies in evaluating the stability of reinforced soil slopes, such as the large number of parameters and complex calculation processes.

Description

Technical Field

[0001] This invention relates to the field of slope engineering technology, and in particular to a method for calculating the shear strength of reinforced soil slopes. Background Technology

[0002] Reinforced soil technology involves reinforcing compacted fill soil to achieve cohesion in the direction of the reinforcement that matches the tensile strength of the reinforcement, thus forming a composite structure. This composite structure possesses excellent capacity to support external forces and its own weight. The reinforced soil structure consists of three main parts: fill soil, embedded reinforcing strips within the fill soil, and wall panels. Within this integrated composite structure, various interacting internal forces exist, including earth pressure acting on the wall surface, tensile force generated by the reinforcement, and frictional force between the fill soil and the reinforcement. These internal forces mutually constrain and balance each other, thereby ensuring the stability of the entire composite structure.

[0003] The limit equilibrium method is widely used in analyzing slope stability. By inputting the slope's shear strength parameters (cohesion and internal friction angle) and basic parameters such as unit weight, the slope's stability coefficient can be calculated. However, when calculating the stability of reinforced slopes, in addition to the aforementioned parameters, the material parameters of the reinforcement (such as spacing, length, and design tensile strength) must also be considered, making the process cumbersome and time-consuming. When the calculated result after substituting the reinforcement material parameters fails to meet the stability coefficient standard specified in the code, the reinforcement material parameters must be adjusted according to the actual situation, and the calculation steps must be repeated until the result meets the code requirements. This process is highly inefficient due to the need for multiple experimental adjustments and calculations. Summary of the Invention

[0004] This invention provides a method for calculating the shear strength of reinforced soil slopes. The purpose is to enable the rapid setting of material parameters for reinforcement and to conveniently and quickly calculate the stability coefficient of reinforced soil slopes, thus solving the problem of low efficiency caused by conventional methods of inputting reinforcement material parameters one by one and performing multiple trial calculations.

[0005] The present invention provides the following technical solution to achieve the above objectives:

[0006] A method for calculating the shear strength of reinforced soil slopes is proposed. Under the premise of knowing the residual sliding force Fn of the soil slope, the method takes into account the placement of reinforcement in the soil slope to improve the slope's anti-sliding capacity, and calculates the shear strength of the reinforced soil slope after the reinforcement is placed.

[0007] The aforementioned method for calculating the shear strength of reinforced soil slopes improves the slope's anti-sliding capacity through the synergistic effect between the reinforcement and the soil slope. This effect is equivalent to improving the cohesion of the soil slope. The improved cohesion c' is calculated by introducing the 120-year long-term design tensile strength Ry of the reinforcement and the vertical spacing Sy of the reinforcement.

[0008] The formula for calculating the cohesion c' in the aforementioned method for calculating the shear strength of reinforced soil slopes is as follows:

[0009]

[0010] In the formula:

[0011] c' - Increased cohesion (kPa)

[0012] F n - Residual sliding force within the reinforcement zone of the earthen slope; (kN / m)

[0013] R y - Reinforcing material's long-term design tensile strength over 120 years; (kN / m)

[0014] S y - Vertical spacing of the reinforcing bars; (m)

[0015] - Angle of internal friction of the soil; (°)

[0016] The aforementioned method for calculating the shear strength of reinforced soil slopes involves substituting the cohesion c' into conventional geotechnical design software to calculate the stability coefficient of the reinforced soil slope.

[0017] Beneficial effects

[0018] Compared with the prior art, the present invention has the following beneficial effects:

[0019] This invention relates to a method for calculating the shear strength of reinforced soil slopes. This method equates the interaction between the reinforcement and the soil to an increase in the slope's cohesion. The increased cohesion, c', can be calculated using the vertical spacing of the reinforcement, the long-term design strength of the reinforcement, and the residual sliding force within the reinforcement area of ​​the slope. Obtaining these parameters is relatively simple, making the calculation process more efficient. This overcomes the inherent shortcomings of existing technologies in evaluating reinforced soil slopes, which involve numerous parameters and complex calculations, providing a more efficient solution for calculating the stability of reinforced soil slopes.

[0020] Furthermore, the formulas involved in this invention are also applicable to the reinforcement design process of earth slopes. Specifically, the cohesion c' is determined by reverse calculation using the safety factor specified in the standard, and this cohesion c' is then substituted into the formulas involved in this invention to derive the reasonable spacing of the reinforcement and the required tensile strength. This method aims to optimize the design scheme, improve design efficiency, and provide theoretical guidance for selecting appropriate reinforcement materials.

[0021] The calculation method of this invention employs a concise and clear formula design, involving a relatively small number of parameters, all of which are common and easily obtained. After obtaining the improved cohesion c' using the calculation method of this invention, the stability of the slope can be further calculated using conventional geotechnical design software. This method has broad application prospects in engineering practice and high practical value. Attached Figure Description

[0022] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the accompanying drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below only relate to some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without any creative effort.

[0023] Figure 1 This is a schematic diagram for the calculation of section 12-12;

[0024] Figure 2 This is a schematic diagram of the calculation for section 14-14;

[0025] Figure 3 A schematic diagram for calculating the remaining sliding force in section 12-12;

[0026] Figure 4 This is a schematic diagram of the stability test of section 12-12;

[0027] Figure 5 A schematic diagram for calculating the remaining sliding force in section 14-14;

[0028] Figure 6 A schematic diagram for calculating the remaining sliding force in section 14-14;

[0029] Figure 7 This is a schematic diagram for the stability verification of section 14-14;

[0030] Figure 8 Legend for fill plot;

[0031] Figure 9 Examples of clay;

[0032] Figure 10 Legend for bedrock;

[0033] Figure 11 A schematic diagram of the calculation of section 12-12 using existing technology;

[0034] Figure 12 A schematic diagram of the calculation of section 14-14 using existing technology;

[0035] Figure 13A schematic diagram showing the position of the polyline at section 12-12, numbered 1, is provided for calculation using existing technology.

[0036] Figure 14 Calculate the position diagram of polyline number 2 in section 12-12 using existing technology;

[0037] Figure 15 A schematic diagram showing the position of the polyline in section 3 of section 12-12 is calculated using existing technology.

[0038] Figure 16 A schematic diagram of the partition location of section 12-12, number 1, is calculated based on existing technology;

[0039] Figure 17 Calculate the partition location diagram of section 2 (section 12-12) using existing technology;

[0040] Figure 18 A schematic diagram of the partition location of section 3 (section 12-12) is calculated based on existing technology;

[0041] Figure 19 A schematic diagram showing the position of the polyline in section 14-14, section number 1, calculated using existing technology;

[0042] Figure 20 A schematic diagram showing the position of the polyline in section 2 of section 14-14, calculated using existing technology;

[0043] Figure 21 A schematic diagram of the partition location of section 14-14, number 1, is calculated based on existing technology;

[0044] Figure 22 Calculate the partition location diagram of section 2 (section 14-14) for the existing technology; Detailed Implementation

[0045] To enable those skilled in the art to better understand the present invention, the technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings.

[0046] It should be noted that in this invention: the terms "comprising" and "having," and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or device that includes a series of steps or units is not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices; the terms "upper," "lower," "left," "right," "front," "rear," "top," "bottom," "inner," "outer," "middle," "vertical," "horizontal," "lateral," "longitudinal," etc., indicate orientation or positional relationships based on the orientation or positional relationships shown in the accompanying drawings. The terminology used is primarily for the purpose of better describing the invention and its embodiments, and is not intended to limit the indicated devices, elements, or components to having a specific orientation, or to construct and operate in a specific orientation. Terms such as "first," "second," etc., are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. Terms such as "installed," "set," "equipped with," "connected," "linked," "socketed," etc., should be interpreted broadly; for example, they can refer to a fixed connection, a detachable connection, or an integral structure; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium, or an internal connection between two devices, elements, or components. Furthermore, some terms, in addition to indicating orientation or positional relationships, may also have other meanings; for example, the term "above" may in some cases indicate a dependency or connection relationship. Those skilled in the art can understand the specific meaning of these terms in this invention according to the specific circumstances.

[0047] Example. A method for calculating the shear strength of a reinforced soil slope, given the residual sliding force F of the slope. n Under the premise of considering the placement of reinforcement materials in the slope to improve the slope's anti-sliding capacity, the shear strength of the reinforced slope after the reinforcement materials are placed is calculated.

[0048] Improving the anti-sliding capacity of a slope through the synergistic effect of reinforcement and soil is equivalent to increasing the cohesion of the slope. This is achieved by incorporating the 120-year long-term design tensile strength R of the reinforcement. y Vertical spacing S of reinforcement material layout yThe increased cohesion c' is calculated. The reinforcement enhances the shear strength parameters of the soil (cohesion and internal friction angle). However, for reinforced slopes, the volume of the slope is much larger than the volume of the reinforcement. The addition of reinforcement does not fundamentally change the particle composition of the slope; therefore, the internal friction angle is still determined by the slope's inherent characteristics. After reinforcement is added to the slope, it acts as a constraint in the event of deformation, working in synergy with the slope to improve its stability. This synergistic effect is achieved by increasing the friction between soil particles, similar to adding "glue" to the slope, effectively increasing its cohesion.

[0049] The formula for calculating the cohesion c' is as follows:

[0050]

[0051] In the formula:

[0052] c' - Increased cohesion (kPa)

[0053] F n - Residual sliding force within the reinforcement zone of the earthen slope; (kN / m)

[0054] R y - Reinforcing material's long-term design tensile strength over 120 years; (kN / m)

[0055] S y - Vertical spacing of reinforcing bars; (m)

[0056] - Angle of internal friction of the soil; (°)

[0057] The purpose of reinforcement is to improve slope stability. Under the safety factor required by specifications, slopes have a certain residual sliding force. Reinforcement can resist this residual sliding force, which is reflected in the increase of shear strength parameters, thereby improving slope stability. Therefore, the numerator in the formula is the residual sliding force minus the design tensile strength of the reinforcement. Furthermore, in slope reinforcement design, the reinforcement is spaced; the smaller the spacing, the higher the slope stability coefficient, and the larger the spacing, the lower the stability coefficient—the two are negatively correlated. Therefore, the design spacing of the reinforcement is considered in the denominator. Finally, the process by which the reinforcement works is closely related to the fill material; the two work together. Since the slope is a nonlinear material, the formula considers the material properties of the fill, expressed by the internal friction angle. The nonlinearity is reflected in the tangent formula. In the formula, the long-term design tensile strength R of the reinforcing steel over 120 years is... y The coefficient 4.5 and the vertical spacing S of the reinforcement arrangement yThe coefficient 10 is an empirical coefficient, derived from the analysis and statistics of a large number of actual reinforced soil slope projects, and obtained after rigorous calculation and verification.

[0058] The stability coefficient of the reinforced soil slope is calculated by substituting the cohesion c' into a conventional geotechnical design software. The conventional geotechnical design software is GEO5 geotechnical design software.

[0059] The calculation method of this invention is further elaborated by taking the engineering application example of the special design project for the layout, protection and drainage facilities of the plant area of ​​the Pannan 2×660MW low calorific value coal resource comprehensive utilization power generation project as an example.

[0060] Two profiles, 12-12 and 14-14, from the application project were selected for calculation using this method, and their stability coefficients were compared with those of the slope after reinforcement was incorporated. Profile 12-12 is shown below. Figure 1 As shown, section 14-14 is as follows Figure 2 As shown;

[0061] Section 12-12 uses 100-type fiber-plastic grid reinforcement with a vertical spacing of 0.76m. The slope height is 22m, divided into two levels. The reinforcement length of the upper level slope is 16m, and the reinforcement length of the lower level slope is 20m.

[0062] Section 14-14 uses two types of fiber-plastic geogrids, type 100 and type 150, with vertical spacing of 0.76m and 0.5m respectively. The slope height is 33m and it is divided into 3 levels. The upper two levels of the slope use type 100 fiber-plastic geogrids, and the lower level of the slope uses type 150 geogrids.

[0063] The structural fill design calculation parameters are as follows:

[0064] Natural density: γ = 20.50 kN / m 3

[0065] Angle of internal friction:

[0066] Cohesion: c ef =2.00 kPa

[0067] Friction angle between structure and soil / rock: δ = 10.00°

[0068] saturated specific gravity: γ sat =21.50kN / m 3

[0069] The design calculation parameters for type 100 and type 150 reinforcing bars are shown in the table below:

[0070]

[0071] Calculation process for section 12-12:

[0072] 1. Calculation using the formulas involved in this invention

[0073] 1) Calculation of residual sliding force, the calculation process is as follows: Figure 3 As shown;

[0074] 2) Calculation of the increase in cohesion c' after reinforcement

[0075] The calculation formula of this invention The calculated value is c' = 37.33 kPa.

[0076] 3) The stability coefficient of the slope is calculated using cohesion c'.

[0077] The stability coefficient of the slope is calculated by replacing the cohesion *c* of the structural fill with *c'*. The calculation results are as follows: Figure 4 As shown;

[0078] Safety factor

[0079] II. Calculation using existing technical methods (the calculation report for section 12-12 exported using GEO5 geotechnical design software is shown below).

[0080] The methods and standards for retaining wall analysis are as follows:

[0081] Verification method:

[0082] Active Earth Pressure Calculation Method: Coulomb Theory

[0083] Passive earth pressure calculation method: Mazindrani (Rankine) theory

[0084] Seismic Load Analysis: GB50330-2013 Technical Specification for Slope Engineering of Buildings in China

[0085] Permissible eccentricity: 0.250

[0086] Internal stability: JTG D30-2015 Chinese Highway Subgrade Design Specification

[0087]

[0088] Stability analysis

[0089] Verification method: Chinese standard

[0090]

[0091] Cross-sectional dimensions

[0092]

[0093] Material

[0094] Reinforcing bar type

[0095]

[0096] Reinforcing bar details

[0097] 1. Paragrid 100

[0098] Quality control tensile strength Tult = 100.00 kN / m

[0099] Long-term strength design value Rt = 69.30 kN / m

[0100] The overall coefficient of the model is uncertain. UNC =1.00

[0101] Calculate partial factors

[0102] Service life: 5 years

[0103] Creep partial factor RF CR =1.31

[0104] Environmental pH: 4.0-9.0

[0105] Durability partial factor RF D =1.08

[0106] Packing particle size: D 50 <0.15mm

[0107] Installation damage factor RF ID =1.02

[0108] reinforcement

[0109]

[0110] Reinforcing bar details

[0111] Reinforcing bar No. 1

[0112] Reinforcement type: Paragrid 100

[0113] Quantity of reinforcing bars: 12

[0114] Reinforcing bar dimensions: Same reinforcing bar length: 20.00m

[0115]

[0116] Reinforcing bar number 2: Reinforcing bar type: Paragrid 100; Quantity: 14

[0117] Reinforcing bar dimensions: Same reinforcing bar length: 16.00m

[0118]

[0119] Geotechnical material parameters

[0120] Fill soil

[0121] Natural density: γ = 20.50 kN / m 3

[0122] Internal friction angle: φ ef =30.00°

[0123] Cohesion: c ef =2.00 kPa

[0124] Friction angle between structure and soil / rock: δ = 15.00°

[0125] saturated specific gravity: γ sat =21.50kN / m 3

[0126] Natural unit weight of clay: γ = 16.30 kN / m 3

[0127] Internal friction angle: φ ef =9.00°

[0128] Cohesion: c ef =33.00 kPa

[0129] Friction angle between structure and soil / rock: δ = 4.50°

[0130] saturated specific gravity: γ sat =16.50kN / m 3

[0131] Natural unit weight of bedrock: γ = 27.00 kN / m 3

[0132] Internal friction angle: φ ef =30.00°

[0133] Cohesion: c ef =200.00kPa

[0134] Friction angle between structure and soil / rock: δ = 15.00°

[0135] saturated specific gravity: γ sat =27.00kN / m 3

[0136] Profile soil layers and specified materials

[0137]

[0138] Back slope

[0139] The slope behind the wall is horizontal

[0140] Groundwater action

[0141] Groundwater level not considered

[0142] Soil resistance before structure

[0143] The soil resistance before the structure was not considered.

[0144] Operating condition phase settings

[0145] Reduce the friction angle between different strata: Do not reduce

[0146] Design Status: Persistent Design Status

[0147] Slope stability analysis

[0148] Verification method:

[0149] Seismic Load Analysis: GB 50330-2013 Technical Specification for Slope Engineering of Buildings in China

[0150]

[0151] polyline

[0152]

[0153] Geotechnical material parameters - effective stress state

[0154]

[0155] Geotechnical material parameters - buoyancy unit weight

[0156]

[0157] Geotechnical material parameters

[0158] Natural unit weight of fill soil: γ=20.50kN / m 3 Stress state: Effective stress; Internal friction angle: φ ef =30.00°

[0159] Cohesion: c ef =2.00 kPa saturated specific gravity: γ sat =21.50kN / m 3 Natural unit weight of clay: γ = 16.30 kN / m 3 Stress state: Effective stress; Internal friction angle: φ ef =9.00°

[0160] Cohesion: c ef =33.00 kPa saturated specific gravity: γ sat =16.50kN / m 3 Natural unit weight of bedrock: γ = 27.00 kN / m 3 Stress state: Effective stress; Internal friction angle: φ ef =30.00°

[0161] Cohesion: c ef =200.00kPa saturated specific gravity: γ sat =27.00kN / m 3 rigid materials

[0162]

[0163] Specified materials and partitions

[0164]

[0165] reinforcement

[0166]

[0167] result

[0168] Analysis 1: Circular Arc Sliding Surface

[0169]

[0170] Reinforcing steel load capacity

[0171] Slope stability verification (Bishop method)

[0172] The total sliding force on the surface: Fa = 3720.66 kN / m

[0173] The sum of the anti-slip forces on the sliding surface: F p =5034.05kN / m

[0174] Downward torque: M a =147023.80kNm / m

[0175] Anti-slip moment: Mp=198923.20kNm / m

[0176] Safety factor

[0177]

[0178] According to the calculation formula of this invention, the slope stability coefficient is 1.348, while the stability coefficient calculated using existing technology is 1.353. The two calculation results are highly similar. According to industry standards, the values ​​must be retained to the hundredths decimal place; therefore, both can be approximated as 1.35. This result fully verifies the effectiveness of the calculation method provided by this invention, achieving the same level of accuracy as existing technologies, and reducing the complexity of the calculation process.

[0179] Calculation process for section 14-14:

[0180] 1. Calculation using the formulas involved in this invention

[0181] 1) Calculation of remaining sliding force

[0182] Section 14-14 involves two types of reinforcing bars. The residual sliding force within the range of type 100 and type 150 reinforcing bars is calculated separately. The calculation results show that the residual sliding force within the range of type 100 reinforcing bars is as follows: Figure 5 The figure shows the residual sliding force within the 150 type reinforcement range, which is 725.55 kN / m. Figure 6 The value shown is 928.68 kN / m.

[0183] 928.68kN / m=1654.23-725.55.

[0184] 2) Calculation of the increase in cohesion c′ after reinforcement

[0185] The calculation formula of this invention The calculations yielded c' = 39.41 kPa for the upper two levels of the slope and c' = 62.64 kPa for the lower one level.

[0186] 3) The stability of the slope is calculated using cohesion c'.

[0187] The stability calculation of the slope was performed by replacing the parameters of the structural fill with c'. The calculation results are as follows: Figure 7 As shown.

[0188] Safety factor

[0189] II. Calculation using existing technical methods (the calculation report for section 14-14 exported using GEO5 geotechnical design software is shown below).

[0190] The methods and standards for retaining wall analysis are as follows:

[0191] Verification method:

[0192] Active Earth Pressure Calculation Method: Coulomb Theory

[0193] Passive earth pressure calculation method: Mazindrani (Rankine) theory; Seismic load analysis: GB 50330-2013 Technical Specification for Slope Engineering of Buildings in China; Allowable eccentricity: 0.250.

[0194] Internal stability: JTG D30-2015 Chinese Highway Subgrade Design Specification

[0195]

[0196] Stability analysis

[0197]

[0198] Cross-sectional dimensions

[0199]

[0200] Material

[0201] Reinforcing bar type

[0202]

[0203] Reinforcing bar details

[0204] 1. Paragrid 100

[0205] Quality control tensile strength T ult =100.00kN / m

[0206] Long-term strength design value R t =69.30kN / m Action model uncertainty overall coefficient FS UNC =1.00 Calculate the partial factor

[0207] Service life: 5 years

[0208] Creep partial factor RF CR =1.31 Environmental pH: 4.0-9.0

[0209] Durability partial factor RF D =1.08 packing particle size:D 50 <0.15mm

[0210] Installation damage factor RF ID =1.02

[0211] 2. Paragrid 150

[0212] Quality control tensile strength T ult =150.00kN / m Long-term strength design value R t =104.97kN / m Action model uncertainty global coefficient FSUNC =1.00 Calculate the partial factor

[0213] Service life: 5 years

[0214] Creep partial factor RF CR =1.31 Environmental pH: 4.0-9.0

[0215] Durability partial factor RF D =1.08 packing particle size:D 50 <0.15mm

[0216] Installation damage factor RF ID =1.01 reinforcement

[0217]

[0218] Reinforcing bar details

[0219] Reinforcing bar No. 1

[0220] Reinforcement type: Paragrid 150

[0221] Quantity of reinforcing bars: 21

[0222] Reinforcing bar dimensions: Same reinforcing bar length

[0223] Reinforcing bar length: 25.00m

[0224]

[0225]

[0226] Reinforcing bar number 2: Reinforcing bar type: Paragrid 100; Quantity: 14

[0227] Reinforcing bar dimensions: Same reinforcing bar length: 26.00m

[0228]

[0229] Reinforcing bar number 3: Reinforcing bar type: Paragrid 100; Quantity: 13

[0230] Reinforcing bar dimensions: same reinforcing bar length

[0231] Reinforcing bar length: 20.00m

[0232]

[0233] Geotechnical material parameters

[0234] Natural unit weight of fill soil: γ=20.50kN / m 3 Internal friction angle: φef =30.00°

[0235] Cohesion: c ef =2.00 kPa, friction angle between structure and soil / rock: δ = 15.00°

[0236] saturated specific gravity: γ sat =21.50kN / m 3 Natural unit weight of clay: γ = 16.30 kN / m 3 Internal friction angle: φ ef =9.00°

[0237] Cohesion: c ef =33.00 kPa, friction angle between structure and soil / rock: δ = 4.50°

[0238] saturated specific gravity: γ sat =16.50kN / m 3 Natural unit weight of bedrock: γ = 27.00 kN / m 3 Internal friction angle: φ ef =30.00°

[0239] Cohesion: c ef =200.00 kPa, friction angle between structure and soil / rock: δ = 15.00°

[0240] saturated specific gravity: γ sat =27.00kN / m 3 Profile soil layers and specified materials

[0241]

[0242] Back slope

[0243] The slope behind the wall is horizontal

[0244] Groundwater action

[0245] Groundwater level not considered

[0246] Soil resistance before structure

[0247] The soil resistance before the structure was not considered.

[0248] Operating condition phase settings

[0249] Reduce the friction angle between different strata: Do not reduce

[0250] Design Status: Persistent Design Status

[0251] Slope stability analysis

[0252] Verification method:

[0253] Seismic Load Analysis: GB 50330-2013 Technical Specification for Slope Engineering of Buildings in China

[0254]

[0255] polyline

[0256]

[0257] Geotechnical material parameters - effective stress state

[0258]

[0259] Geotechnical material parameters - buoyancy unit weight

[0260]

[0261] Geotechnical material parameters

[0262] Natural unit weight of fill soil: γ=20.50kN / m 3 Stress state: Effective stress; Internal friction angle: φ ef =30.00°

[0263] Cohesion: c ef =2.00 kPa saturated specific gravity: γ sat =21.50kN / m 3 Natural unit weight of clay: γ = 16.30 kN / m 3 Stress state: Effective stress; Internal friction angle: φ ef =9.00°

[0264] Cohesion: c ef =33.00 kPa saturated specific gravity: γ sat =16.50kN / m 3 Natural unit weight of bedrock: γ = 27.00 kN / m 3 Stress state: Effective stress; Internal friction angle: φ ef =30.00°

[0265] Cohesion: c ef =200.00kPa saturated specific gravity: γ sat =27.00kN / m 3 rigid materials

[0266]

[0267] Specified materials and partitions

[0268]

[0269] reinforcement

[0270]

[0271]

[0272] Groundwater type: No groundwater. Tension cracks were not entered.

[0273] Seismic load

[0274] Earthquakes not considered

[0275] Operating condition phase design status: Persistent design status results

[0276] analyze

[0277] Circular arc sliding surface

[0278]

[0279] Reinforcing steel load capacity

[0280]

[0281] Slope stability verification (Bishop method)

[0282] The total sliding force on the surface: Fa = 7618.06 kN / m

[0283] The total anti-slip force on the sliding surface: Fp = 10429.12 kN / m

[0284] Downward torque: M a = 370520.81 kNm / m

[0285] Anti-slip moment: Mp=507242.98kNm / m

[0286]

[0287] According to the calculation formula of this invention, the slope stability coefficient is 1.373, while the stability coefficient calculated using existing technology is 1.368. The two calculation results are highly similar. According to industry standards, the values ​​must be retained to the hundredths decimal place; therefore, both can be approximated as 1.37. This result fully verifies the effectiveness of the calculation method provided by this invention, achieving the same level of accuracy as existing technologies, and reducing the complexity of the calculation process.

[0288] Obviously, the above description is only a part of the embodiments of the present invention, and not all of the embodiments. The above embodiments are not intended to limit the present invention, and various modifications and variations can be made to the present invention by those skilled in the art. Any combination, modification, equivalent substitution, improvement, and all other embodiments that can be made by those skilled in the art within the spirit and principles of the present invention should be within the protection scope of the present invention.

Claims

1. A method for calculating the shear strength of reinforced soil slopes, characterized in that: Given the remaining sliding force of the slope F n Under the premise of considering the placement of reinforcement in the slope to improve the slope's anti-sliding capacity, the shear strength of the reinforced slope after the reinforcement is placed is calculated. Improving the anti-sliding capacity of a slope through the synergistic effect of reinforcement and soil is equivalent to increasing the cohesion of the slope. This is achieved by incorporating the 120-year long-term design tensile strength of the reinforcement. R y Vertical spacing of reinforcing bars S y Calculate the improved cohesion ; The cohesion The calculation formula is as follows: ； In the formula: - Increased cohesion (kPa) F n - Residual sliding force within the reinforcement zone of the earth slope; (kN / m) R y - 120-year long-term design tensile strength of reinforcing steel; (kN / m) - Vertical spacing of the reinforcing bars; (m) - Angle of internal friction of the soil (°); Improved cohesion The stability coefficient of the reinforced soil slope is calculated by substituting the values ​​into conventional geotechnical design software.

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