CN111719347A - Foundation treatment method and device - Google Patents
Foundation treatment method and device Download PDFInfo
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- CN111719347A CN111719347A CN202010526404.XA CN202010526404A CN111719347A CN 111719347 A CN111719347 A CN 111719347A CN 202010526404 A CN202010526404 A CN 202010526404A CN 111719347 A CN111719347 A CN 111719347A
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B2/00—General structure of permanent way
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- E—FIXED CONSTRUCTIONS
- E01—CONSTRUCTION OF ROADS, RAILWAYS, OR BRIDGES
- E01B—PERMANENT WAY; PERMANENT-WAY TOOLS; MACHINES FOR MAKING RAILWAYS OF ALL KINDS
- E01B2/00—General structure of permanent way
- E01B2/006—Deep foundation of tracks
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- E—FIXED CONSTRUCTIONS
- E02—HYDRAULIC ENGINEERING; FOUNDATIONS; SOIL SHIFTING
- E02D—FOUNDATIONS; EXCAVATIONS; EMBANKMENTS; UNDERGROUND OR UNDERWATER STRUCTURES
- E02D3/00—Improving or preserving soil or rock, e.g. preserving permafrost soil
- E02D3/12—Consolidating by placing solidifying or pore-filling substances in the soil
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- 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
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Abstract
The embodiment of the invention discloses a method and a device for processing a foundation, wherein the method comprises the following steps: aiming at the detection result of the foundation, obtaining the distribution parameters of a hard shell stratum contained in the foundation; determining the bearing capacity of the hard shell stratum according to the distribution parameters; determining the piling parameters for arranging the powder-jet piles in the hard-shell stratum based on the bearing capacity; and driving a powder-jet pile into the hard-shell stratum according to the piling parameters to obtain the composite foundation.
Description
Technical Field
The invention relates to the field of railway special roadbed construction engineering, in particular to a foundation treatment method and a foundation treatment device, which are mainly suitable for a general speed railway with the speed per hour being less than or equal to 200 km/h.
Background
In recent years, powder-injection piles are widely used in railway soft soil roadbed foundation treatment as a deep soft soil foundation reinforcing technology, and the physical and mechanical properties of the powder-injection piles are better. However, if the stratum is ignored and the powder-spraying long pile is directly adopted to reinforce the soft soil foundation, some problems often exist, for example, in the reinforcement of the soft soil foundation with the thin hard shell layer, in order to meet the bearing capacity of the foundation, people often ignore the geological condition of the stratum, the long pile is still selected during the design, the back pressure of the soil body is increased along with the increase of the construction depth, the controllability of the powder-spraying pile construction is reduced, and the uniformity of the powder-spraying pile stirring is difficult to ensure. In addition, the construction quality of the powder spraying pile is greatly influenced by the quality of operators, and especially the construction quality of the long pile has higher requirement on the operation level of the operators, so that the pile forming quality is difficult to grasp, the construction progress and the construction quality are influenced, and the manufacturing cost of the powder spraying long pile is higher.
Disclosure of Invention
In view of the above, it is desirable to provide a ground-based processing method according to embodiments of the first aspect of the present invention.
The technical scheme of the invention is realized as follows:
the embodiment of the invention provides a foundation treatment method, which comprises the following steps:
aiming at the detection result of the foundation, obtaining the distribution parameters of a hard shell stratum contained in the foundation;
determining the bearing capacity of the hard shell stratum according to the distribution parameters;
determining the piling parameters for arranging the powder-jet piles in the hard-shell stratum based on the bearing capacity;
and driving a powder-jet pile into the hard-shell stratum according to the piling parameters to obtain the composite foundation.
Optionally, the obtaining, according to the detection result of the foundation, a distribution parameter of a hard shell formation included in the foundation includes:
and acquiring the depth and the thickness of the hard shell stratum and the distribution range in the foundation by utilizing geological drilling, standard penetration tests, static sounding or dynamic sounding.
Optionally, the obtaining, according to the detection result of the foundation, a distribution parameter of a hard shell formation included in the foundation further includes:
obtaining physical and mechanical parameters of the hard shell stratum by using a sample test; the physical parameters include thickness and shear strength.
Optionally, before obtaining the distribution parameters of the hard shell formation contained in the foundation according to the detection result of the foundation, the method further includes:
determining the design grade of the foundation where the hard shell stratum is located according to the requirement of the upper foundation on the bearing capacity; and the theoretical bearing capacity corresponding to the design grade meets the requirement of the upper roadbed on the bearing capacity.
Optionally, the determining, based on the bearing capacity, a piling parameter for setting a powder injection pile in the hard-shell formation includes:
determining the pile length and the total pile number of the powder spraying pile based on the theoretical bearing capacity corresponding to the design grade and the actual bearing capacity of the hard shell stratum and in combination with the distribution parameters of the hard shell stratum;
determining the pile spacing of the powder spraying piles based on the cross sectional area and the area replacement rate of the powder spraying piles;
determining a reinforcement range based on the distribution parameters of the hard shell stratum;
and determining the pile distribution form of the powder spraying piles based on the reinforcement range and the pile spacing.
Optionally, the pile length comprises: a minimum length within a length range consistent with the design grade and the distribution parameters of the hard shell formation.
Optionally, the inter-post spacing comprises: a minimum spacing within a range of spacings consistent with the design grade and distribution parameters of the hard shell formation.
Optionally, the determining, based on the bearing capacity, a piling parameter for setting a powder injection pile in the hard-shell formation further includes:
based on the physics parameters, an appropriate toe type is determined.
Optionally, the determining a suitable toe type based on the physics parameters comprises: if the burial depth of the hard shell stratum is larger than a first preset value or the thickness of the hard shell stratum is smaller than a second preset value, adopting an enlarged head pile tip;
and if the burial depth of the hard shell stratum is not greater than a first preset value or the thickness of the hard shell stratum is not less than a second preset value, adopting a conical pile tip.
Optionally, determining a piling parameter for setting the powder injection pile in the hard-shell formation based on the bearing capacity, further comprising:
and (3) adding a curing agent into the powder spraying pile to increase the pile body strength of the powder spraying pile.
Optionally, after the driving the powder injection pile into the hard shell stratum according to the driving parameters to obtain a composite foundation, the method further comprises:
if the difference value between the actual bearing capacity of the composite foundation and the theoretical bearing capacity corresponding to the design grade is within the range of an error threshold, determining that the construction is finished;
and if the difference value between the actual bearing capacity and the theoretical bearing capacity corresponding to the design grade exceeds the error threshold range, detecting the foundation again.
In a second aspect, an embodiment of the present invention provides a ground processing apparatus, including:
the obtaining module is used for obtaining distribution parameters of a hard shell stratum contained in a foundation according to a detection result of the foundation;
the first determining module is used for determining the bearing capacity of the hard shell stratum according to the distribution parameters;
the second determination module is used for determining the piling parameters of setting the powder-jet piles in the hard-shell stratum based on the bearing capacity;
and the piling module is used for driving a powder-jet pile into the hard-shell stratum according to the piling parameters to obtain the composite foundation.
The foundation treatment method and the foundation treatment device provided by the embodiment of the invention are mainly suitable for the ordinary speed railway with the speed per hour less than or equal to 200 km/h. The method comprises the steps of obtaining distribution parameters of a hard shell stratum contained in a foundation according to a detection result of the foundation, determining the bearing capacity of the hard shell stratum according to the distribution parameters, then determining piling parameters of powder-jet piles arranged on the hard shell stratum based on the bearing capacity, and driving the powder-jet piles into the hard shell stratum according to the piling parameters to obtain the composite foundation. Through the utilization of the thin and hard shell stratum in the soft soil stratum, the flexible setting of pile driving parameters such as pile length, pile spacing and the like is realized, the disturbance to in-situ foundation soil is reduced, the stirring uniformity of a pile body is improved, and meanwhile, the requirement on the operation level of constructors is also reduced, so that the pile forming quality is ensured, the controllability of powder spraying pile construction is improved, the effect of soil among piles is greatly exerted, and a better composite foundation effect is realized.
Drawings
FIG. 1 is a schematic flow chart of a method for treating a foundation according to an embodiment of the present invention;
FIG. 2 is a flowchart illustrating an embodiment of a method for performing a ground based process;
fig. 3 is an application scenario diagram of a ground-based processing method according to an embodiment of the present invention;
FIG. 4 is a diagram illustrating a functional relationship between pile length and bearing capacity of a single pile according to an embodiment of the present invention;
FIG. 5 is a schematic diagram of static sounding Ps provided in an embodiment of the present invention;
fig. 6 is a schematic structural diagram of a ground-based processing device according to an embodiment of the present invention.
Detailed Description
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 only a part of the embodiments of the present invention, and not all of the embodiments. 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.
Referring to fig. 1, fig. 1 is a schematic flow chart of a foundation treatment method according to an embodiment of the present disclosure, where the foundation treatment method according to the embodiment of the present disclosure may include:
s110: and aiming at the detection result of the foundation, obtaining the distribution parameters of the hard shell stratum contained in the foundation.
The foundation treatment method provided by the embodiment of the invention is applied to the soft soil foundation reinforcement environment containing the hard shell stratum, and the hard shell stratum can be used as a bearing layer to support an upper building body.
The distribution condition of the hard shell stratum in the foundation including the depth, the distribution position and the like of the hard shell stratum can be obtained through combining geological drilling, sample test and other methods, and in addition, the physical parameters of the hard shell stratum can be ascertained.
S120: and determining the bearing capacity of the hard shell stratum according to the distribution parameters.
The bearing capacity of the hard crust layer is related to the distribution of the hard crust layer in the foundation and the physical parameters of the hard crust formation itself. It can be understood that the wider the distribution range of the hard shell formation, the greater the thickness and the shear strength, and the positive correlation between the corresponding bearing capacities, that is, the wider the distribution range of the hard shell formation, the greater the thickness and the shear strength, and the greater the corresponding bearing capacity.
S130: and determining the piling parameters for arranging the powder-jet piles in the hard-shell stratum based on the bearing capacity.
The piling parameters comprise pile length, pile spacing, total pile number and the like. By utilizing the bearing capacity of the hard shell stratum, the pile length can be adjusted, long piles are not needed to be adopted in the whole foundation range, and the actual test shows that the bearing capacity of a single pile and the pile length are in negative correlation. That is to say, within the bearing limit, the smaller the pile length is, the greater the bearing capacity thereof is, so that under the condition of providing the same bearing capacity, compared with the use of a long pile, the adoption of a short pile can save raw materials, and simultaneously, the requirement on the operation level of constructors can be reduced, so that the pile forming quality is ensured, and the construction controllability is improved.
S140: according to the piling parameters, driving a powder jet pile into the hard shell stratum to obtain the composite foundation
The composite foundation is obtained by piling in the original soft soil foundation containing the hard shell stratum according to the determined piling parameters. By utilizing the hard shell stratum, the length of the powder spraying pile can be adjusted according to the distribution parameters of the hard shell stratum. The pile length can be properly reduced at the position where the hard shell stratum is distributed, and the hard shell stratum is used as a bearing; and long piles are still adopted at the position without the hard shell stratum, so that the long piles and the short piles are alternated, and the construction is more facilitated compared with the case that the long piles are adopted completely.
In this embodiment, a hard shell stratum in a soft soil foundation is used as a bearing layer, the bearing capacity which can be provided by the hard shell stratum is determined according to the distribution parameters of the hard shell stratum, the piling parameters of the powder injection pile are determined based on the bearing capacity, and the powder injection pile is set according to the piling parameters, so that the composite foundation is obtained. By utilizing the thin and hard shell stratum in the soft soil stratum, the length of the pile body is reduced, the requirement on the operation level of constructors is lowered, the pile forming quality is ensured, and the controllability of powder spraying pile construction is improved.
Optionally, the obtaining, according to the detection result of the foundation, a distribution parameter of a hard shell formation included in the foundation includes:
and acquiring the depth and the thickness of the hard shell stratum and the distribution range in the foundation by utilizing geological drilling, standard penetration tests, static sounding or dynamic sounding.
Specifically, the rough condition of the soft soil stratum can be judged by combining geological data and geological survey of the area, and then the specific distribution parameters of the hard shell stratum can be obtained by one or more of geological drilling, standard penetration test, static sounding, dynamic sounding and the like. The specific distribution parameters include, but are not limited to, the depth, thickness, and distribution range in soft soil foundations, including, but not limited to, the length, width, and location of the hard shell formations.
Optionally, the obtaining, according to the detection result of the foundation, a distribution parameter of a hard shell formation included in the foundation further includes:
obtaining physical and mechanical parameters of the hard shell stratum by using a sample test; the physical parameters include thickness and shear strength.
The hard shell stratum is a stratum with higher hardness compared with a soft soil stratum, the hard shell stratum is not unique in material, and the shear strength of the stratums with different materials is often different, so that the shear strength of the hard shell stratum can be accurately obtained by adopting a sample test. It will be readily appreciated that the thickness of the hard shell formation is positively correlated with the load bearing capacity that it is capable of providing.
Optionally, before obtaining the distribution parameters of the hard shell formation contained in the foundation according to the detection result of the foundation, the method further includes:
determining the design grade of the foundation where the hard shell stratum is located according to the requirement of the upper foundation on the bearing capacity; and the theoretical bearing capacity corresponding to the design grade meets the requirement of the upper roadbed on the bearing capacity.
The design grade of the foundation is related to the external environment of the foundation, such as in an earthquake zone area, before a house is built, earthquake grade evaluation is performed to determine the earthquake resistance grade of the built house, and the design parameters of houses with different earthquake resistance grades often differ. In the embodiment, the bearing capacity requirements of the high-speed rail line and the common highway are definitely different according to the comprehensive consideration of the external environment of the foundation, such as the use type of the foundation, and other factors, such as climate factors, also affect the design grade of the foundation.
Optionally, the determining, based on the bearing capacity, a piling parameter for setting a powder injection pile in the hard-shell formation includes:
determining the pile length and the total pile number of the powder spraying pile based on the theoretical bearing capacity corresponding to the design grade and the actual bearing capacity of the hard shell stratum and in combination with the distribution parameters of the hard shell stratum;
determining the pile spacing of the powder spraying piles based on the cross sectional area and the area replacement rate of the powder spraying piles;
determining a reinforcement range based on the distribution parameters of the hard shell stratum;
and determining the pile distribution form of the powder spraying piles based on the reinforcement range and the pile spacing.
On the basis of knowing the bearing capacity of the hard shell stratum, the piling parameters of the powder jet piles are combined, the theoretical bearing capacity of the final composite foundation can be obtained, and understandably, the theoretical bearing capacity of the composite foundation is not less than the theoretical bearing capacity corresponding to the design grade, so that the piling parameters can be further determined by predetermining the theoretical bearing capacity of the composite foundation. According to actual measurement, the bearing capacity of a single pile is in negative correlation with the pile length, and the overall bearing capacity of the powder spraying pile is in positive correlation with the total pile number. Through the cross-sectional area and the area replacement rate of the powder spraying piles, corresponding soil body units can be obtained, and further the pile spacing of the powder spraying piles is determined.
And determining the reinforcing range according to distribution parameters of the hard shell stratum, such as distribution position, depth, thickness and the like. The reinforcement range is the area for reinforcing the stratum, and under the condition that the length of the reinforced stratum is not changed, the reinforcement width is widened, so that the effect of soil between piles can be exerted greatly.
According to the reinforcing range and the pile spacing, the pile distribution form of the powder spraying piles can be determined. Under the wider reinforcement area, the smaller pile spacing is adopted, so that the effect of soil between piles can be greatly exerted, a better composite foundation effect is achieved, the requirement of post-construction settlement can be met, and the construction controllability is improved.
This embodiment has realized reducing to pile shaft length, has reduced the requirement to constructor operation level to through the adjustment to consolidating scope and stake interval, reduced the disturbance to original place foundation soil, improved the homogeneity of pile shaft stirring, make the effect of stake soil obtain great performance, play better composite foundation effect.
Optionally, the pile length comprises: a minimum length within a length range consistent with the design grade and the distribution parameters of the hard shell formation.
According to actual measurement data, the bearing capacity of a single pile of the powder spraying pile is inversely related to the pile length, the pile length is not suitable to be too large, the whole bearing capacity of the powder spraying pile needs to consider the bearing capacity requirement corresponding to the design grade, the pile length cannot be too short, although the bearing capacity of the single pile of the short pile is large, the shear strength of a hard shell stratum cannot be exceeded, and parameters such as the depth of the hard shell stratum also need to be considered. Therefore, the minimum pile length which meets the bearing capacity requirement corresponding to the design grade and meets the distribution parameter of the hard-shell stratum exists by integrating the design grade and the distribution parameter of the hard-shell stratum, so that the reduction of the pile body length is realized, the integral construction cost is reduced, the requirement on the operation level of constructors is reduced, the pile forming quality is ensured, and the controllability of powder spray pile construction is improved.
Optionally, the inter-post spacing comprises: a minimum spacing within a range of spacings consistent with the design grade and distribution parameters of the hard shell formation.
By adopting wider reinforcement range and smaller pile spacing treatment, the effect of soil between piles can be greatly exerted, a better composite foundation effect is achieved, and the requirement of post-construction settlement can be well met by later-stage residual settlement. The design grade and the distribution parameters of the hard shell stratum are comprehensively considered, and a minimum pile spacing which not only meets the bearing capacity requirement corresponding to the design grade, but also meets the distribution parameters of the hard shell stratum exists.
Optionally, the determining, based on the bearing capacity, a piling parameter for setting a powder injection pile in the hard-shell formation further includes:
based on the physics parameters, an appropriate toe type is determined.
The pile tip type of the powder spraying pile can comprise an enlarged head pile tip and a conical pile tip, and the shapes of the pile tips are different, so that the penetration capacities of the pile tips are different. Therefore, it is necessary to determine the appropriate pile tip type based on the physical parameters of the hard-shell formation. Specifically, the physical parameters to be considered include the thickness, depth and shear strength of the hard shell formation, the pile tip types can be divided into an enlarged head pile tip and a tapered pile tip, if the depth of the thin hard shell layer is deeper or the thickness is thinner or the shear strength is smaller, the enlarged bottom large head pile is preferentially adopted, and conversely, the tapered pile tip is adopted. It will be readily appreciated that the enlarged head tip has a tip portion with a larger surface area than the tapered tip.
Optionally, the determining a suitable toe type based on the physics parameters comprises: if the burial depth of the hard shell stratum is larger than a first preset value or the thickness of the hard shell stratum is smaller than a second preset value, adopting an enlarged head pile tip;
and if the burial depth of the hard shell stratum is not greater than a first preset value or the thickness of the hard shell stratum is not less than a second preset value, adopting a conical pile tip.
Specifically, a first threshold value a and a second threshold value b are preset, and the burial depth and the thickness of the hard shell stratum are determined by detecting the hard shell stratum, wherein the burial depth is the depth of the hard shell stratum in the soft soil stratum. If the burial depth of the hard shell stratum is larger than a first preset value a or the thickness of the hard shell stratum is smaller than a second preset value b, adopting the enlarged head pile tip, and otherwise, adopting the conical pile tip.
Optionally, determining a piling parameter for setting the powder injection pile in the hard-shell formation based on the bearing capacity, further comprising:
and (3) adding a curing agent into the powder spraying pile to increase the pile body strength of the powder spraying pile.
Specifically, the incorporation amount of the curing agent may be determined based on the test results or experience.
Optionally, after the driving the powder injection pile into the hard shell stratum according to the driving parameters to obtain a composite foundation, the method further comprises:
if the difference value between the actual bearing capacity of the composite foundation and the theoretical bearing capacity corresponding to the design grade is within the range of an error threshold, determining that the construction is finished;
and if the difference value between the actual bearing capacity and the theoretical bearing capacity corresponding to the design grade exceeds the error threshold range, detecting the foundation again.
In this embodiment, the theoretical bearing capacity corresponding to the design grade is greater than the requirement of the upper roadbed for the bearing capacity, and the influence of the inevitable error in the actual construction process on the whole is reduced. The error threshold is in the difference range of the theoretical bearing capacity corresponding to the design grade and the requirement of the upper roadbed on the bearing capacity. Specifically, the error threshold may be a difference between a theoretical bearing capacity corresponding to the design grade and a requirement of the upper roadbed on the bearing capacity. And when the difference value between the actual bearing capacity and the theoretical bearing capacity corresponding to the design grade exceeds the error threshold range, detecting the foundation again.
In a specific embodiment, as shown in fig. 2 and fig. 3, a specific implementation flowchart and an application scenario diagram are respectively shown. The implementation process is as follows:
(1) the method is characterized in that the requirements of the upper roadbed on the bearing capacity and the settlement are determined, the design grade is determined firstly, the requirements of the upper roadbed on the bearing capacity and the settlement are determined by combining the specification and the related requirements, and a basis is provided for reasonably arranging piles.
The foundation settlement refers to the settlement of the surface of a foundation with compacted and hard soil layers under the action of additional stress, and the design grade is determined according to the requirements of the upper roadbed on bearing capacity and settlement.
(2) Determining a pile end bearing layer: on the basis of combining regional geological data and geological survey, geological stratification is accurately carried out through means of geological drilling, penetration tests, static sounding, dynamic sounding and the like, parameters such as the distribution range, the depth, the thickness and the like of the thin and hard stratum are found out, meanwhile, samples and the like of the corresponding stratum are adopted for indoor tests, physical and mechanical indexes of the soil layer are obtained, and a pile end holding layer and corresponding parameters are determined.
One or a combination of multiple detection means can be adopted as the detection means, and static sounding is shown in fig. 5.
(3) And calculating the bearing capacity and the upper load of the natural foundation to verify the applicability of the composite foundation.
The geological condition of the natural foundation and the bearing capacity which can be provided can be determined through the detection data, if the geological condition of the natural foundation and the bearing capacity which can be provided do not accord with the standard of constructing the composite foundation, the site needs to be reselected, otherwise, the method is suitable for constructing the composite foundation.
(4) By analyzing the physical and mechanical parameters (thickness, shear strength and the like) characteristics of the thin hard shell layer, selecting a proper pile tip type (a conical pile tip and an expanded head pile tip), and preferentially adopting an expanded-base large-head pile if the thin hard shell layer is deeply buried or has a small thickness; determining the pile diameter of the powder spraying pile according to the type of a powder spraying drilling machine; and determining the reinforcement ranges of the two sides of the roadbed through calculation and tests.
(5) The proper amount of the curing agent to be incorporated is selected by experiment or empirically.
(6) And determining the pile length by reverse calculation by using a composite foundation bearing capacity calculation formula according to geological conditions and the requirements of the superstructure on bearing capacity and settlement or according to the requirements of the bearing capacity of a single pile and the bearing capacity of the composite foundation required by design.
The functional relationship diagram of the pile length and the single-pile bearing capacity is shown in fig. 4, and it can be known that the pile length and the single-pile bearing capacity are in negative correlation, and the shorter the pile length, the larger the single-pile bearing capacity.
(7) And comprehensively determining the pile spacing according to the cross section area and the area replacement rate of the powder spraying pile.
In the composite foundation, one pile and the soil body between piles borne by the pile are a composite soil body unit, and the ratio of the section area of the pile to the area of the composite soil body unit in the composite soil body unit becomes the area replacement rate. Therefore, the pile spacing can be comprehensively determined according to the cross-sectional area and the area replacement rate of the powder injection pile.
(8) And calculating the total pile number required by reinforcement according to the area required by the roadbed.
(9) And calculating the actual bearing capacity of the composite foundation after the overall arrangement is completed.
In this embodiment, specific embodiments have been described in detail in the foregoing embodiments, and are not described in detail again.
As shown in fig. 6, the present embodiment provides a ground processing apparatus, including: a obtaining module 210, configured to obtain, for a detection result of a foundation, a distribution parameter of a hard shell formation included in the foundation.
The foundation is detected by combining geological drilling, sample test and other methods, so that the distribution condition of the hard shell stratum in the foundation, including the depth, the distribution position and the like of the hard shell stratum can be obtained, and in addition, the physical parameters of the hard shell stratum, such as the thickness, the length, the width and the shear strength, can be detected.
A first determining module 220, configured to determine a bearing capacity of the hard-shell formation according to the distribution parameter.
The bearing capacity of the hard crust layer is related to the distribution of the hard crust layer in the foundation and the physical parameters of the hard crust formation itself. It can be understood that the wider the distribution range of the hard shell formation, the greater the thickness and the shear strength, and the positive correlation between the corresponding bearing capacities, that is, the wider the distribution range of the hard shell formation, the greater the thickness and the shear strength, and the greater the corresponding bearing capacity.
And a second determining module 230, configured to determine a piling parameter for setting the powder injection pile in the hard-shell formation based on the bearing capacity.
The piling parameters comprise pile length, pile spacing, total pile number and the like. By utilizing the bearing capacity of the hard shell stratum, the pile length can be adjusted, long piles are not needed to be adopted in the whole foundation range, and the actual test shows that the bearing capacity of a single pile and the pile length are in negative correlation. That is to say, within the bearing limit, the smaller the pile length is, the greater the bearing capacity thereof is, so that under the condition of providing the same bearing capacity, compared with the use of a long pile, the adoption of a short pile can save raw materials, and simultaneously, the requirement on the operation level of constructors can be reduced, so that the pile forming quality is ensured, and the construction controllability is improved.
And the piling module 240 is used for driving a powder-jet pile into the hard-shell stratum according to the piling parameters to obtain the composite foundation.
The composite foundation is obtained by piling in the original soft soil foundation containing the hard shell stratum according to the determined piling parameters. By utilizing the hard shell stratum, the length of the powder spraying pile can be adjusted according to the distribution parameters of the hard shell stratum. The pile length can be properly reduced at the position where the hard shell stratum is distributed, and the hard shell stratum is used as a bearing; and long piles are still adopted at the position without the hard shell stratum, so that the long piles and the short piles are alternated, and the construction is more facilitated compared with the case that the long piles are adopted completely.
In this embodiment, a hard shell stratum in a soft soil foundation is used as a bearing layer, the bearing capacity which can be provided by the hard shell stratum is determined according to the distribution parameters of the hard shell stratum, the piling parameters of the powder injection pile are determined based on the bearing capacity, and the powder injection pile is set according to the piling parameters, so that the composite foundation is obtained. By utilizing the thin and hard shell stratum in the soft soil stratum, the length of the pile body is reduced, the requirement on the operation level of constructors is lowered, the pile forming quality is ensured, and the controllability of powder spraying pile construction is improved.
Optionally, the obtaining module 210 is configured to obtain the depth, the thickness and the distribution range in the foundation of the hard shell formation by geological drilling, penetration testing, static sounding or dynamic sounding.
Specifically, the rough condition of the soft soil stratum can be judged by combining geological data and geological survey of the area, and then the specific distribution parameters of the hard shell stratum can be obtained by one or more of geological drilling, standard penetration test, static sounding, dynamic sounding and the like. The specific distribution parameters include, but are not limited to, the depth, thickness, and distribution range in soft soil foundations, including, but not limited to, hard shell formation length, width, and location.
Optionally, the obtaining module 210 is configured to obtain a physical-mechanical parameter of the hard-shell formation by using a sample test; the physical parameters include thickness and shear strength.
The hard shell stratum is a stratum with higher hardness compared with a soft soil stratum, the hard shell stratum is not unique in material, and the shear strength of the stratums with different materials is often different, so that the shear strength of the hard shell stratum can be accurately obtained by adopting a sample test. It will be readily appreciated that the thickness of the hard shell formation is positively correlated with the load bearing capacity that it is capable of providing.
Optionally, the foundation treatment device further comprises a third determination module, wherein the third determination module is used for determining the design grade of the foundation where the hard shell formation is located according to the requirement of the upper roadbed on the bearing capacity; and the theoretical bearing capacity corresponding to the design grade meets the requirement of the upper roadbed on the bearing capacity.
The design grade of the foundation is related to the external environment of the foundation, such as in an earthquake zone area, before a house is built, earthquake grade evaluation is performed to determine the earthquake resistance grade of the built house, and the design parameters of houses with different earthquake resistance grades often differ. In the embodiment, the bearing capacity requirements of the high-speed rail line and the common highway are definitely different according to the comprehensive consideration of the external environment of the foundation, such as the use type of the foundation, and other factors, such as climate factors, also affect the design grade of the foundation.
Optionally, the second determining module 230 is configured to determine the pile length and the total number of the powder injection piles based on the theoretical bearing capacity corresponding to the design grade and the actual bearing capacity of the hard-shell formation, and in combination with the distribution parameters of the hard-shell formation;
determining the pile spacing of the powder spraying piles based on the cross sectional area and the area replacement rate of the powder spraying piles;
determining a reinforcement range based on the distribution parameters of the hard shell stratum;
and determining the pile distribution form of the powder spraying piles based on the reinforcement range and the pile spacing.
On the basis of knowing the bearing capacity of the hard shell stratum, the piling parameters of the powder jet piles are combined, the theoretical bearing capacity of the final composite foundation can be obtained, and understandably, the theoretical bearing capacity of the composite foundation is not less than the theoretical bearing capacity corresponding to the design grade, so that the piling parameters can be further determined by predetermining the theoretical bearing capacity of the composite foundation. According to actual measurement, the bearing capacity of a single pile is in negative correlation with the pile length, and the overall bearing capacity of the powder spraying pile is in positive correlation with the total pile number. Through the cross-sectional area and the area replacement rate of the powder spraying piles, corresponding soil body units can be obtained, and further the pile spacing of the powder spraying piles is determined.
And determining the reinforcing range according to distribution parameters of the hard shell stratum, such as distribution position, depth, thickness and the like. The reinforcement range is the area for reinforcing the stratum, and under the condition that the length of the reinforced stratum is not changed, the reinforcement width is widened, so that the effect of soil between piles can be exerted greatly.
According to the reinforcing range and the pile spacing, the pile distribution form of the powder spraying piles can be determined. Under the wider reinforcement area, the smaller pile spacing is adopted, so that the effect of soil between piles can be greatly exerted, a better composite foundation effect is achieved, the requirement of post-construction settlement can be met, and the construction controllability is improved.
This embodiment has realized reducing to pile shaft length, has reduced the requirement to constructor operation level to through the adjustment to consolidating scope and stake interval, reduced the disturbance to original place foundation soil, improved the homogeneity of pile shaft stirring, make the effect of stake soil obtain great performance, play better composite foundation effect.
Optionally, the pile length determined by the second determining module 203 includes: a minimum length within a length range consistent with the design grade and the distribution parameters of the hard shell formation.
According to actual measurement data, the bearing capacity of a single pile of the powder spraying pile is inversely related to the pile length, the pile length is not suitable to be too large, the whole bearing capacity of the powder spraying pile needs to consider the bearing capacity requirement corresponding to the design grade, the pile length cannot be too short, although the bearing capacity of the single pile of the short pile is large, the shear strength of a hard shell stratum cannot be exceeded, and parameters such as the depth of the hard shell stratum also need to be considered. Therefore, the minimum pile length which meets the bearing capacity requirement corresponding to the design grade and meets the distribution parameter of the hard-shell stratum exists by integrating the design grade and the distribution parameter of the hard-shell stratum, so that the reduction of the pile body length is realized, the integral construction cost is reduced, the requirement on the operation level of constructors is reduced, the pile forming quality is ensured, and the controllability of powder spray pile construction is improved.
Optionally, the peg distance determined by the second determining module 203 includes: a minimum spacing within a range of spacings consistent with the design grade and distribution parameters of the hard shell formation.
By adopting wider reinforcement range and smaller pile spacing treatment, the effect of soil between piles can be greatly exerted, a better composite foundation effect is achieved, and the requirement of post-construction settlement can be well met by later-stage residual settlement. The design grade and the distribution parameters of the hard shell stratum are comprehensively considered, and a minimum pile spacing which not only meets the bearing capacity requirement corresponding to the design grade, but also meets the distribution parameters of the hard shell stratum exists.
Optionally, the second determination module 203 is configured to determine a suitable toe type based on the physics parameters.
The pile tip type of the powder spraying pile can comprise an enlarged head pile tip and a conical pile tip, and the shapes of the pile tips are different, so that the penetration capacities of the pile tips are different. Therefore, it is necessary to determine the appropriate pile tip type based on the physical parameters of the hard-shell formation. Specifically, the physical parameters to be considered include the thickness, depth and shear strength of the hard shell formation, the pile tip types can be divided into an enlarged head pile tip and a tapered pile tip, if the depth of the thin hard shell layer is deeper or the thickness is thinner or the shear strength is smaller, the enlarged bottom large head pile is preferentially adopted, and conversely, the tapered pile tip is adopted. It will be readily appreciated that the tip portion of the enlarged head toe is of greater area than the tapered toe.
Optionally, the second determining module 203 is configured to adopt an enlarged head pile tip if the burial depth of the hard-shell formation is greater than a first preset value or the thickness of the hard-shell formation is smaller than a second preset value;
and if the burial depth of the hard shell stratum is not greater than a first preset value or the thickness of the hard shell stratum is not less than a second preset value, adopting a conical pile tip.
Specifically, a first threshold value a and a second threshold value b are preset, and the burial depth and the thickness of the hard shell stratum are determined by detecting the hard shell stratum, wherein the burial depth is the depth of the hard shell stratum in the soft soil stratum. If the burial depth of the hard shell stratum is larger than a first preset value a or the thickness of the hard shell stratum is smaller than a second preset value b, adopting the enlarged head pile tip, and otherwise, adopting the conical pile tip.
Optionally, the second determining module 203 is configured to determine that a curing agent is doped in the powder injection pile to increase the pile body strength of the powder injection pile.
Specifically, the incorporation amount of the curing agent may be determined based on the test results or experience.
Optionally, the foundation treatment device further includes a checking module, where the checking module is configured to determine that construction is completed if a difference between an actual bearing capacity of the composite foundation and a theoretical bearing capacity corresponding to the design grade is within an error threshold range;
and if the difference value between the actual bearing capacity and the theoretical bearing capacity corresponding to the design grade exceeds the error threshold range, detecting the foundation again.
In this embodiment, the theoretical bearing capacity corresponding to the design grade is greater than the requirement of the upper roadbed for the bearing capacity, and the influence of the inevitable error in the actual construction process on the whole is reduced. The error threshold is in the difference range of the theoretical bearing capacity corresponding to the design grade and the requirement of the upper roadbed on the bearing capacity. Specifically, the error threshold may be a difference between a theoretical bearing capacity corresponding to the design grade and a requirement of the upper roadbed on the bearing capacity. And when the difference value between the actual bearing capacity and the theoretical bearing capacity corresponding to the design grade exceeds the error threshold range, detecting the foundation again.
In the several embodiments provided in the present application, it should be understood that the disclosed method and apparatus may be implemented in other ways. The above-described apparatus embodiments are merely illustrative.
The units described as separate parts may or may not be physically separate, and parts displayed as units may or may not be physical units, that is, may be located in one place, or may be distributed on a plurality of network units; some or all of the units can be selected according to actual needs to achieve the purpose of the solution of the embodiment.
In addition, all the functional units in the embodiments of the present invention may be integrated into one processing module, or each unit may be separately used as one unit, or two or more units may be integrated into one unit; the integrated unit can be realized in a form of hardware, or in a form of hardware plus a software functional unit.
The above description is only for the specific embodiments of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily conceive of the changes or substitutions within the technical scope of the present invention, and all the changes or substitutions should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the appended claims.
Claims (12)
1. A method of ground treatment, the method comprising:
aiming at the detection result of the foundation, obtaining the distribution parameters of a hard shell stratum contained in the foundation;
determining the bearing capacity of the hard shell stratum according to the distribution parameters;
determining the piling parameters for arranging the powder-jet piles in the hard-shell stratum based on the bearing capacity;
and driving a powder-jet pile into the hard-shell stratum according to the piling parameters to obtain the composite foundation.
2. The method according to claim 1, wherein the obtaining of the distribution parameters of the hard shell formation contained in the foundation according to the detection result of the foundation comprises:
and acquiring the depth and the thickness of the hard shell stratum and the distribution range in the foundation by utilizing geological drilling, standard penetration tests, static sounding or dynamic sounding.
3. The method according to claim 2, wherein the obtaining of the distribution parameters of the hard shell formation contained in the foundation according to the detection result of the foundation further comprises:
obtaining physical and mechanical parameters of the hard shell stratum by using a sample test; the physical parameters include thickness and shear strength.
4. The method according to claim 3, wherein before the probing of the foundation results in obtaining distribution parameters of a hard shell formation contained in the foundation, the method further comprises:
determining the design grade of the foundation where the hard shell stratum is located according to the requirement of the upper foundation on the bearing capacity; and the theoretical bearing capacity corresponding to the design grade meets the requirement of the upper roadbed on the bearing capacity.
5. The method of claim 4, wherein determining pile driving parameters for placing a shotcrete pile in the hard-shell formation based on the bearing capacity comprises:
determining the pile length and the total pile number of the powder spraying pile based on the theoretical bearing capacity corresponding to the design grade and the actual bearing capacity of the hard shell stratum and in combination with the distribution parameters of the hard shell stratum;
determining the pile spacing of the powder spraying piles based on the cross sectional area and the area replacement rate of the powder spraying piles;
determining a reinforcement range based on the distribution parameters of the hard shell stratum;
and determining the pile distribution form of the powder spraying piles based on the reinforcement range and the pile spacing.
6. The method of claim 5, wherein the pile length comprises: a minimum length within a length range consistent with the design grade and the distribution parameters of the hard shell formation.
7. The method of claim 5, wherein the inter-peg spacing comprises: a minimum spacing within a range of spacings consistent with the design grade and distribution parameters of the hard shell formation.
8. The method of claim 5, wherein determining pile driving parameters for placing a shotcrete pile in the hard-shelled formation based on the bearing capacity further comprises:
based on the physics parameters, an appropriate toe type is determined.
9. The method of claim 8, wherein determining an appropriate toe type based on the physics parameters comprises: if the burial depth of the hard shell stratum is larger than a first preset value or the thickness of the hard shell stratum is smaller than a second preset value, adopting an enlarged head pile tip;
and if the burial depth of the hard shell stratum is not greater than a first preset value or the thickness of the hard shell stratum is not less than a second preset value, adopting a conical pile tip.
10. The method of claim 5, wherein determining pile driving parameters for placing a shotcrete pile in the hard-shelled formation based on the bearing capacity further comprises:
and (3) adding a curing agent into the powder spraying pile to increase the pile body strength of the powder spraying pile.
11. The method of claim 5, wherein after said driving a shotcrete pile into said hard-shell formation to obtain a composite foundation according to said driving parameters, said method further comprises:
if the difference value between the actual bearing capacity of the composite foundation and the theoretical bearing capacity corresponding to the design grade is within the range of an error threshold, determining that the construction is finished;
and if the difference value between the actual bearing capacity and the theoretical bearing capacity corresponding to the design grade exceeds the error threshold range, detecting the foundation again.
12. A ground-based processing apparatus, characterized in that the apparatus comprises:
the obtaining module is used for obtaining distribution parameters of a hard shell stratum contained in a foundation according to a detection result of the foundation;
the first determining module is used for determining the bearing capacity of the hard shell stratum according to the distribution parameters;
the second determination module is used for determining the piling parameters of setting the powder-jet piles in the hard-shell stratum based on the bearing capacity;
and the piling module is used for driving a powder-jet pile into the hard-shell stratum according to the piling parameters to obtain the composite foundation.
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Cited By (1)
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| CN114134886A (en) * | 2021-12-10 | 2022-03-04 | 中交隧道工程局有限公司 | Construction method of triaxial mixing pile for deep and thick silt layer of foundation pit |
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