CN114197445B - Double-row sheet pile pressure reduction self-unloading method and double-row pile structure thereof - Google Patents
Double-row sheet pile pressure reduction self-unloading method and double-row pile structure thereof Download PDFInfo
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Abstract
A double-row sheet pile pressure reduction and self-unloading method comprises a self-unloading double-row sheet pile design and installation flow and a self-unloading double-row sheet pile mechanical calculation optimal process, and a double-row sheet pile structure can be obtained by designing the method and comprises a double-row sheet pile, unloading geotextile, filling soil, an anchoring ring and a top support, wherein the double-row sheet pile is vertically inserted into a soft soil foundation of a region to be constructed; the top support cross bar is arranged at the top of the double-row sheet pile; a plurality of anchoring rings are arranged on the inner sides of the double-row sheet piles, unloading soil cloth is hung on the anchoring rings, and the space enclosed by the double-row sheet piles is divided into a plurality of layers; and the filling soil is filled on the unloading geotextile until the enclosed space is full. According to the double-row sheet pile, the deadweight of the filling soil on the double-row sheet pile is shared by the unloading geotextile, so that the soil stress in the filling soil is greatly reduced, and the soil pressure load of the filling soil on the double-row sheet pile is also greatly reduced.
Description
Technical Field
The invention relates to a pressure-reducing self-unloading method, in particular to a pressure-reducing self-unloading method of a double-row sheet pile and a double-row sheet pile structure thereof.
Background
The projects such as large docks, ship locks, water locks, piers, artificial islands and the like are increased day by day in China, the technical challenges of engineering construction brought by larger water depth need to be met, and the technical requirements on cofferdams and foundation pit retaining structures are higher and higher. Under the condition, the single-row steel sheet piles often cannot achieve the expected supporting effect, the problems of large horizontal displacement of a weir top, insufficient structural rigidity and the like exist, the supporting rigidity of the cofferdam must be improved, the displacement of a pile body is restricted, and the double-row steel sheet pile cofferdam is an effective measure for enhancing the rigidity of the cofferdam. The double-row steel sheet piles are characterized in that a row of parallel equidistant steel sheet piles are inserted on the basis of a single row of steel sheet piles, soil is filled between the piles, and the two rows of steel sheet piles are connected by using a cross brace of a pile top to connect the two rows of steel sheet piles into a whole. The double-row steel sheet piles make up the defect that a single-row steel sheet pile is suitable for deepwater conditions, and the cost of the double-row steel sheet piles is not greatly different from that of the single-row steel sheet piles, so that the double-row steel sheet piles have better application prospects. However, the filled soil in the double-row steel sheet piles often generates a large soil pressure, so that the steel sheet piles generate bending deformation protruding outwards, if the cofferdam is higher, the soil pressure required to be borne by the steel sheet piles is larger, the deformation of the generated steel sheet pile structure is larger, and if the rigidity of the steel sheet pile structure is insufficient, the integrity and the service working performance of the double-row steel sheet pile structure are seriously influenced.
Therefore, the design can stabilize double sheet pile soil retaining structure and can promote the new scheme of sheet pile rigidity, and is particularly urgent.
Disclosure of Invention
The application overcomes the defects of the prior art, and therefore, a novel technical scheme is disclosed, the filling soil in the double-row sheet piles is subjected to vertical load sharing in the height direction of the cofferdam and is transferred to the sheet piles, the stress state of the soil body, particularly the soil pressure at the mud surface position, can be greatly reduced, the reduction range of the soil pressure acting on the sheet piles can be up to more than 60%, and the method is an effective method for realizing the pressure reduction and unloading of the double-row sheet piles.
In order to achieve the purpose, the invention adopts a double-row sheet pile pressure reduction self-unloading method, which comprises a self-unloading double-row sheet pile design and installation flow and a self-unloading double-row sheet pile mechanical calculation optimal process;
and 2, performing an optimal mechanical calculation process on the self-unloading double-row sheet pile, and performing mechanical calculation on the built self-unloading double-row sheet pile structure to obtain the loads of the double-row sheet pile under the action of the unloading force of the geotextile with different layers.
Further, the design and installation process of the self-unloading double-row sheet pile comprises the following steps:
1) Firstly, the construction area is treated to be measured and positioned, the boundary condition is definite, the piling construction of double rows of sheet piles is carried out on the soft soil foundation, the distance between two rows of steel sheet piles is set as d, and the soft soil foundation is driven intoThe depth of the steel sheet pile is H 2 The height of the steel sheet pile cantilever above the soft soil foundation is H 1 Then, mounting a top support at the top of the double rows of steel sheet piles, pumping accumulated water in a space area formed by the double rows of steel sheet piles after the top support is mounted until the soft soil foundation is exposed, and removing floating mud;
2) The inner sides of double rows of steel sheet piles above the ground of the soft soil foundation are provided with anchoring rings, the anchoring rings are provided with n layers, and the height of each layer is set to be H 1 /n；
3) Laying a first layer of unloading geotextile in a space formed by the double-row steel plate sheet pile cofferdam and anchoring the first layer of unloading geotextile to an anchoring ring, wherein reinforcing strips are arranged on the unloading geotextile, the reinforcing strips are arranged in a vertical and horizontal mode, the intervals of the reinforcing strips are the same, then filling soil on the unloading geotextile, and finally tamping the filling soil;
4) And (4) after the first layer is laid, repeating the step (3), continuing the construction of the previous layer of filled soil until the design position of the unloading geotextile on the uppermost layer is reached, totally and cumulatively laying n layers of unloading geotextiles, and finally reserving a certain superelevation in the filled soil at the pile top of the double-row steel sheet pile.
Further, the mechanical calculation optimization process of the self-unloading double-row sheet pile comprises the following steps of:
1) When the unloading geotechnical cloth is not arranged between the double rows of steel sheet piles, the total soil pressure of the common double rows of steel sheet piles, namely the sum of the active soil pressures generated by the double rows of steel sheet piles toppled over under the outward action of the internal soil body is T1=1/2 gamma H 2 K a The calculated point soil pressure at the bottom of the double rows of steel sheet piles is the maximum, and is K1= HK a Gamma, gamma is soil density, H is height of soil body in sheet pile, K a Is the active soil pressure coefficient;
2) When n layers of unloading geotextile are arranged between double rows of steel sheet piles, if n layers of unloading geotextile separate soil layers, the total soil pressure calculation formula is
The calculated point soil pressure at the bottom of the double-row steel sheet pile is maximum, and the calculation formula is
Where i is an iteration parameter of no practical significance, K γ The soil pressure transmission coefficient is 0-1, which is defined as the soil pressure proportion transmitted by the upper layer filling soil to the lower layer filling soil, namely the transmission coefficient is multiplied by the bottom soil pressure of the upper layer filling soil to obtain the top soil pressure of the lower layer filling soil;
3)K γ the value can be judged according to the concave degree of the unloading geotextile and the separation degree of the filling soil of the upper layer and the lower layer, when the filling soil is settled to cause the unloading geotextile to start concave, K γ The size of the unloading geotextile concave is reduced from 1, and when the concave of the unloading geotextile is close to the limit or the upper and lower layers of filling soil are almost completely separated without contact, K is γ It is close to 0; assuming that the proportion of the contact area of the upper filling soil layer and the lower filling soil layer of the unloading geotextile to the initial contact area is delta X in the process that the unloading geotextile is close to the limit from the beginning of sinking to the sinking surface, constructing K γ Functional relationship with Δ X, K γ K is a proportionality coefficient, and is greater than 0;
4) The unloading ratio is 0-1 through a calculation formula B =1-T2/T1 of the ratio of the active soil pressure of the double-row steel sheet piles provided with the unloading geotechnical cloth to the active soil pressure of the double-row steel sheet piles without the unloading geotechnical cloth. And obtaining the limit, wherein when B is equal to 1, the unloading effect is realized after the unloading geotextile is installed, and when B is equal to 0, the effect of installing the unloading geotextile is equal to that of not installing the geotextile. The value of B is (0,1), which shows that the unloading effect can be better when the unloading geotextile is installed. Meanwhile, when the required unloading ratio B is eta%, K is used γ And determining that the number of layers of the required unloading geotextile can be reversely calculated.
The double-row sheet pile structure designed according to the pressure reduction self-unloading method comprises double-row sheet piles, unloading geotextile, filling soil, an anchoring ring and a top support, wherein the double-row sheet piles are vertically inserted into a soft soil foundation of a region to be constructed; the top support cross bar is arranged at the top of the double-row sheet pile; a plurality of anchoring rings are arranged on the inner sides of the double-row sheet piles, unloading geotextile is hung on the anchoring rings, and the space enclosed by the double-row sheet piles is divided into a plurality of layers; and the filling soil is filled on the unloading geotextile until the enclosed space is full.
Furthermore, the stability of the whole structure formed by the double-row sheet pile structure is realized by the self weight of the filling soil in the double-row sheet pile, and the self weight of the filling soil is shared by the unloading geotextile, so that the soil stress in the filling soil is greatly reduced, the soil pressure load of the filling soil on the double-row sheet pile is also greatly reduced, and the unloading function is realized.
Further, the double-row sheet piles adopt steel sheet piles.
Further, the top support is H-shaped steel.
Furthermore, the anchoring rings are arranged in a plurality of pairs and fixed on the inner sides of the double-row steel sheet piles at a certain interval height from the ground position of the soft soil foundation after floating mud is cleaned, wherein the same pair of anchoring rings are positioned on the same horizontal plane.
Furthermore, the unloading geotextile is reinforced by sewing reinforced belts on the bottom surface of the unloading geotextile, the reinforced belts are uniformly and criss-cross arranged, the geotextile takes the shape of a Chinese character 'tian', the arrangement interval is 1-3 m, the unloading geotextile shares the weight load proportion of the soil filled on the unloading geotextile to be 20-80%, and then the weight load proportion is transmitted to the double-row sheet pile through the reinforced belts sewn on the bottom surface of the unloading geotextile. The unloading geotextile adopts polypropylene long strand silk; the ultimate bearing capacity of the reinforced belt can reach 2-5 times of the weight of the soil filled on the unloading geotextile.
Furthermore, the unloading geotextile is acted by the vertical downward gravity of the filling soil to form a lower concave surface, the tension borne by the unloading geotextile is increased, the double-row sheet pile is pulled more tightly, and the filling soil is extruded and compacted.
The invention shares the vertical load by filling soil in the double rows of sheet piles and transfers the filling soil to the sheet piles at two sides, thereby greatly reducing the stress state of the soil body, particularly the soil pressure at the position of a mud surface, and the unloading effect can reach more than 60 percent. Meanwhile, the double-row sheet pile has the advantages of simple structure, convenience in implementation, improvement on the integrity and rigidity of the double-row sheet piles and the like.
Drawings
FIG. 1 is a schematic structural view of a self-unloading load double-row sheet pile;
FIG. 2 is a schematic view of a self-unloading load geotextile reinforcement structure;
FIG. 3 is a schematic diagram illustrating the operation of a self-discharging load double-row sheet pile;
fig. 4 shows the soil mechanics calculation of the unloading-free geotextile of the self-unloading load double-row sheet pile;
fig. 5 shows the mechanical calculation of the geotechnical distribution by arranging 3 layers of unloading for the self-unloading double-row sheet piles;
FIG. 6 unloading ratio and transfer coefficient K of unloading double-row pile γ Graph of the relationship of (1);
figure 7 shows the deformation of the unloading geotextile during the settlement of the filling soil;
fig. 8 is a schematic application diagram of the self-unloading load double-row sheet pile cofferdam in the embodiment.
In the figure: 1. double rows of sheet piles; 2. unloading the geotextile; 3. filling soil; 4. an anchoring ring; 5. supporting the top; 6. soft soil foundation; 7. and (4) reinforcing the rib belt.
Detailed Description
The following describes the embodiments in further detail with reference to fig. 1 to 8. The method comprises a design and installation flow of the self-unloading double-row sheet pile and an optimal mechanical calculation process of the self-unloading double-row sheet pile;
and 2, performing an optimal mechanical calculation process on the self-unloading double-row sheet pile, and performing mechanical calculation on the built self-unloading double-row sheet pile structure to obtain the loads of the double-row sheet piles under the action of the unloading force of the unloading geotextile 2 with different layers.
Laying a first layer of unloading geotextile 2 in a space formed by the double-row sheet pile cofferdam and anchoring the unloading geotextile 2 to an anchoring ring, wherein the unloading geotextile adopts a needling density of 400 spines/cm 2 The prepared 600g polypropylene filament geotextile has the thickness of 3.5mm, the tensile strength of 45kN/m, the elongation at break of 75%, the tear strength of 1300N, the bursting strength of 7200N, the vertical permeability coefficient of 2.0mm/s and the effective aperture of 0.08mm. And then filling soil is arranged on the unloading geotextile, wherein the filling soil 3 is blow-filled sandy silt, and the filling soil is compacted by adopting a small machine.
The anchoring ring is provided with 3 layers on the inner side of the double-row sheet pile above the mud surface, the height of each layer is 1.7m, and the longitudinal arrangement distance is 50cm. The top support is 400 multiplied by 13 multiplied by 21 type H shaped steel. The ribbed belt is arranged longitudinally and transversely at the same interval of 50cm, and the ultimate tensile strength is not less than 50kN.
After the first layer is laid, the construction of the upper layer of filling soil 3 is continued until the design position of the unloading geotextile 2 on the uppermost layer, and a certain superelevation is reserved in the filling soil 3 at the pile top of the double rows of steel plate piles to reserve the settlement of 0.3-1.0 meter.
When the single-layer unloading geotextile 2 separates the soil layer, the total soil pressure of the self-unloading double-row pile is calculated to be 1/2. Gamma.H of the soil layer according to a formula 2 K a The maximum soil pressure of the calculated point is HK at the bottom soil layer a And gamma. When the double-layer unloading geotextile separates the soil layers, the total soil pressure is calculated according to a formulaSoil layer combined into 1/4. Gamma.H 2 K a (K γ + 1), the maximum soil pressure of the calculated point is (K) in the bottom soil layer γ +1)HK a Gamma/2. As shown in FIG. 5, the total soil pressure of the three-layer unloading geotextile separated soil layer and the self-unloading double-row pile, namely the sum of the active soil pressures of the soil bodies in different layers after no settlement, is calculated according to a formula and added to be 1/18 (2K) γ 2 + 4K γ +3) γH 2 K a The maximum soil pressure of the calculation point is also (K) in the bottom soil layer γ 2 +K γ + 1)HK a Gamma/3. According to the mathematic induction method and the analogy, if n layers of unloading geotextile 2 separate soil layers exist, the total soil pressure calculation formula is
The maximum soil pressure formula is
Wherein K γ The soil pressure transmission coefficient is 0-1, which is defined as the soil pressure proportion transmitted by the upper layer filling soil to the lower layer filling soil, namely the transmission coefficient is multiplied by the bottom soil pressure of the upper layer filling soil to obtain the top soil pressure of the lower layer filling soil; the size of the unloading geotextile can be judged according to the sinking degree of the unloading geotextile and the separation degree of the upper and lower layers of filling soil, and when the unloading geotextile sinks due to the sedimentation of the filling soil, K γ The size of the unloading geotextile concave is reduced from 1, and when the concave of the unloading geotextile is close to the limit or the upper and lower layers of filling soil are almost completely separated without contact, K is γ It is close to 0; if K γ If the value is 1, the complete transmission is not reduced, which is equal to the condition that no unloading geotextile 2 is arranged, and if the value is K, the unloading geotextile 2 is arranged γ The unloading geotextile completely bears the upper filling soil pressure when the unloading geotextile is 0, and the soil pressure transfer coefficient K γ The size depends on the settlement condition of the filling soil 3 and the concave condition of the unloading geotextile 2, and the more the settlement is, the smaller the transfer coefficient is.
Unloading ratio and transmission coefficient K of self-unloading double-row piles in the embodiment γ Curve of relation (c)As shown in fig. 6, the self-unloading double-row pile takes the three-layer unloading geotextile as an example to separate the soil layer stress, and the unloading ratio is defined as the ratio of the total soil pressure reduction value of the self-unloading double-row pile divided by the total soil pressure of the common double-row pile, that is, the ratio is used for describing the total soil pressure load reduction ratio of the self-unloading double-row pile compared with the common double-row pile; wherein if K γ When the stress state is 0, the unloading geotextile 2 completely separates the upper and lower layers of filling soil 3 in the stress state, the unloading ratio is close to 70 percent, and K is in the middle of practical engineering γ Generally between 0.1 and 0.5, the unloading ratio can reach 50 to 70 percent, and the larger the transfer coefficient is, the smaller the unloading ratio of the geotextile is.
In this embodiment K γ The experimental values in the actual engineering are shown in 3 graphs of fig. 7, and since the filled soil and the original foundation soil are different in each engineering case, the experiment can be used to obtain the approximate K more quickly γ Numerical values, wherein K in FIG. 7a γ =1, the upper and lower filling soil layers are not separated and still completely contacted at this time, and the unloading geotextile is not sunken; k in FIGS. 7a to 7b γ The contact area of the upper filling soil layer and the lower filling soil layer is only about half of the original contact area when the volume is reduced to 0.5 from 1 and the filling soil layer in the figure 7b is settled, so the volume is reduced, and the geotextile begins to sink to cause the generation of gaps; k in FIGS. 7b to 7c γ Slowly decreasing from 0.5 to close to 0, the upper and lower filling soil layers are almost completely separated in fig. 7c, leaving only a small portion of the contact area of the upper and lower filling soil layers. In the experiment, the proportion of the contact area of the upper filling soil layer and the lower filling soil layer of the unloading geotextile to the initial contact area is delta X, and K is constructed γ Functional relationship with Δ X, K γ K is a proportionality coefficient, and is greater than 0;
by the calculation formula of the ratio of the active soil pressure of the double-row steel sheet pile provided with the unloading geotextile to the active soil pressure of the double-row steel sheet pile without the unloading geotextile, B =1-T2/T1, B represents the unloading ratio and is between 0 and 1,
when the required unloading ratio B is eta%, K is used γ And determining that the number of the required unloading geotextile layers can be reversely calculated.
The double-row sheet pile structure is designed according to the pressure reduction and self-unloading method and comprises a double-row sheet pile 1, unloading geotextile 2, filling soil 3, an anchoring ring 4 and a top support 5, wherein the double-row sheet pile 1 is vertically inserted into a soft soil foundation 6 of a region to be constructed; the top support cross bar is arranged at the top of the double-row sheet pile; a plurality of anchoring rings 4 are arranged on the inner side of the double-row sheet pile 1, a load-unloading geotextile 2 is hung on the anchoring rings 4, and the space enclosed by the double-row sheet pile 1 is divided into a plurality of layers; and the filling soil 3 is filled on the unloading geotextile 2 until the enclosed space is full.
The stability of the overall structure formed by the double-row sheet piles in the embodiment is realized by the dead weight of the filling soil in the double-row sheet piles, and the dead weight of the filling soil on the double-row sheet piles is shared by the unloading geotextile 2, so that the soil stress in the filling soil is greatly reduced, the soil pressure load of the filling soil on the double-row sheet piles 1 is greatly reduced, and the unloading function is realized.
In this embodiment, the double row sheet piles 1 are steel sheet piles.
In the embodiment, a plurality of pairs of anchoring rings 4 are arranged, and are fixed at the inner sides of the double-row steel sheet piles 1 at certain intervals from the ground position of the soft soil foundation 6 after floating mud is cleaned to the upper part, wherein the same pair of anchoring rings 4 are all positioned on the same horizontal plane.
In the embodiment, as shown in fig. 2, the unloading geotextile 2 is reinforced by sewing a reinforced belt 7 on the bottom surface thereof, the reinforced belts 7 are uniformly arranged in a longitudinal and transverse direction at an arrangement interval of 1-3 m, the unloading geotextile 2 shares a weight load proportion of the soil body filled on the unloading geotextile 2 of 20-80%, and then the weight load proportion is transmitted to the double-row sheet pile 1 through the reinforced belts 7 sewed on the bottom surface of the unloading geotextile 2. The ultimate bearing capacity of the reinforced belt 7 can reach 2-5 times of the weight of the soil filled on the unloading geotextile 2.
In the embodiment, the unloading geotextile 2 is acted by the vertical downward gravity of the filling soil to form a lower concave surface, the tension born by the unloading geotextile is increased, the double-row sheet pile 1 is pulled to be tighter, and the compaction of the filling soil in extrusion is facilitated.
The embodiments of the present invention are not intended to limit the scope of the present invention, and therefore, all equivalent changes in structure, shape, and principle according to the present invention should be covered by the claims.
Claims (7)
1. A double-row sheet pile pressure reduction self-unloading method is characterized in that: the method comprises the design and installation process of the self-unloading double-row sheet pile and the mechanical calculation optimal process of the self-unloading double-row sheet pile;
step 1, designing and installing a flow of a self-unloading double-row sheet pile, and reasonably constructing a double-row sheet pile structure in an area to be constructed to form a cofferdam;
step 2, performing mechanical calculation on the built self-unloading double-row sheet pile structure to obtain the loads of the double-row sheet piles under the action of the unloading force of the geotextile with different layers in the mechanical calculation optimal process of the self-unloading double-row sheet piles;
the design and installation process of the self-loading double-row sheet pile comprises the following steps:
2.1 Firstly, measuring and positioning a to-be-constructed area, defining boundary conditions, piling double rows of sheet piles on a soft soil foundation, setting the distance between the two rows of sheet piles to be d, and setting the depth of the double rows of sheet piles driven into the soft soil foundation to be H 2 The height of the cantilever of the double-row sheet pile above the soft soil foundation is H 1 Then, mounting a top support (5) at the top of the double-row sheet piles, and pumping accumulated water in a space area formed by combining the double-row sheet piles after the top support is mounted until a soft soil foundation (6) is exposed, and removing floating mud;
2.2 Anchoring rings are arranged on the inner sides of double rows of sheet piles above the ground of the soft soil foundation, n layers of anchoring rings are arranged, and the height of each layer is set to be H 1 /n；
2.3 Laying a first layer of unloading geotextile in a space formed by the double-row sheet pile cofferdam and anchoring the unloading geotextile to the anchoring ring (4), wherein reinforcing strips (7) are arranged on the unloading geotextile (2), the longitudinal and transverse arrangement intervals of the reinforcing strips are the same, then filling the unloading geotextile with filling soil (3), and tamping the filling soil (3);
2.4 After the first layer is laid, repeating the step 2.3, continuing to construct the previous layer of filling soil (3) until the design position of the unloading geotextile (2) at the uppermost layer, totally and cumulatively laying n layers of unloading geotextiles, and finally reserving a certain superelevation in the filling soil (3) at the pile top of the double-row sheet pile;
the mechanical calculation optimization process of the self-unloading double-row sheet pile comprises the following steps:
3.1 When no unloading geotextile is arranged between the double-row sheet piles, the total soil pressure of the common double-row sheet pile piles, namely the sum of the active soil pressures generated by the outward dumping of the double-row sheet piles under the action of the internal soil body, is T1=1/2 gamma H 2 K a The calculated point soil pressure at the bottom of the double-row sheet piles is the maximum and is K1= HK a Gamma, gamma is soil density, H is height of soil body in double row sheet pile, K a Is the active soil pressure coefficient;
3.2 When n layers of unloading geotextile (2) are arranged between double rows of sheet piles, if n layers of unloading geotextile separate soil layers, a total soil pressure calculation formula
n is more than or equal to 2, the calculated point soil pressure at the bottom of the double-row sheet pile is maximum, and the calculation formula is
n is more than or equal to 2, wherein K γ The soil pressure transmission coefficient is 0-1, which is defined as the soil pressure proportion transmitted by the upper layer filling soil to the lower layer filling soil, namely the transmission coefficient is multiplied by the bottom soil pressure of the upper layer filling soil to obtain the top soil pressure of the lower layer filling soil;
3.3)K γ the value is judged according to the concave degree of the unloading geotextile and the separation degree of the filling soil of the upper layer and the lower layer, when the filling soil is settled to cause the unloading geotextile (2) to start concave, K γ The size of the unloading geotextile concave is reduced from 1, and when the concave of the unloading geotextile is close to the limit or the upper and lower layers of filling soil are almost completely separated without contact, K is γ It is close to 0; assuming that the proportion of the contact area of the upper filling soil layer and the lower filling soil layer of the unloading geotextile to the initial contact area is delta X in the process that the unloading geotextile is close to the limit from the beginning of sinking to the sinking surface, constructing K γ Functional relationship with Δ X, K γ K is a ratio = k × Δ X, k isExample coefficients;
3.4 B =1-T2/T1 by a calculation formula of the ratio of the active soil pressure of the double-row sheet pile provided with the unloading geotextile to the active soil pressure of the double-row sheet pile without the unloading geotextile, wherein B represents the unloading ratio, T2 is smaller than T1 by calculation, B is between 0 and 1, and when the required unloading ratio B is eta%, because K is equal to γ And determining that the number n of the required unloading geotextile layers is reversely calculated.
2. The double-row sheet pile pressure reduction self-unloading method as claimed in claim 1, characterized in that: the top support is H-shaped steel.
3. A double row sheet pile structure designed by the pressure reduction self-unloading method of claim 1, characterized in that: the structure comprises double-row sheet piles (1), unloading geotextile (2), filling soil (3), an anchoring ring (4) and a top support (5), wherein the double-row sheet piles are vertically inserted into a soft soil foundation (6) of a region to be constructed; the top support cross bar is arranged at the top of the double-row sheet pile; a plurality of anchoring rings are arranged on the inner sides of the double-row sheet piles, unloading geotextile is hung on the anchoring rings, and the space enclosed by the double-row sheet piles is divided into a plurality of layers; and the filling soil (3) is filled on the unloading geotextile until the enclosed space is full.
4. A double row sheet pile structure as claimed in claim 3, in which: and a plurality of pairs of anchoring rings (4) are arranged, and are fixed at the inner sides of the double rows of sheet piles at certain intervals from the ground position of the soft soil foundation after floating mud is cleaned to the upper part, wherein the same pair of anchoring rings are all positioned on the same horizontal plane.
5. A double row sheet pile structure as claimed in claim 3, in which: the bottom surface of the unloading geotextile (2) is sewed with a reinforced belt (7) for reinforcement, and the reinforced belt is uniformly crossed vertically and horizontally.
6. A double row sheet pile structure as claimed in claim 3, in which: the unloading geotextile (2) adopts polypropylene long strand silk.
7. A double row sheet pile structure as claimed in claim 3, in which: the ribbed belts (7) are crossed vertically and horizontally to form a field shape, the arrangement distance is 1-3 meters, and the ultimate bearing capacity of the ribbed belts reaches 2-5 times of the weight of the soil body filled on the unloading geotextile (2).
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| JP2004197403A (en) * | 2002-12-18 | 2004-07-15 | Data Tou:Kk | Steel pipe sheet pile well foundation |
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| CN213571995U (en) * | 2020-07-15 | 2021-06-29 | 中国水利水电第十四工程局有限公司 | Self-stabilizing water retaining full-recovery composite cantilever pile structure |
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| JP2004197403A (en) * | 2002-12-18 | 2004-07-15 | Data Tou:Kk | Steel pipe sheet pile well foundation |
| CN106759083A (en) * | 2016-12-19 | 2017-05-31 | 中交第航务工程勘察设计院有限公司 | Suitable for the form general model method for designing of deep water discharging type sheet pile bulkhead structure |
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