Double-layer raw material field structure constructed on deep soft soil foundation and construction method thereof

Abstract

The application provides a double-layer raw material yard structure constructed on deep soft soil foundation and a construction method thereof. The raw material yard structure comprises an underground stockyard, an overground stockyard and an artificial up-and-down passage. The underground stockyard is formed by excavating to the bottom surface of the soft soil layer after constructing an underground continuous wall below the soft soil layer, and a raft layer is arranged on the bottom surface of the underground stockyard. An inlet conveying passage and an outlet conveying passage are arranged on the two sides of the underground stockyard respectively. The side columns on the two sides of the overground stockyard are arranged above the underground continuous wall, and a stock shed is arranged on the top of the side columns. The bottom surface of the overground stockyard is composed of a bearing beam and a raft layer arranged on the bearing beam. A supporting column is arranged between the overground stockyard and the underground stockyard. The application omits the step of soft foundation treatment, saves the occupied space, fully utilizes the strength and bearing capacity of the foundation soil in the depth correction, greatly improves the bearing capacity, and avoids various diseases caused by the ground settlement to the structure.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of geotechnical engineering foundation treatment and underground space development and utilization design, in particular to a double-layer raw material yard structure constructed on deep soft soil foundation and a construction method thereof. BACKGROUND

[0002] The raw material yard is an indispensable important part of a steel enterprise, and bears more than 95% of the material preparation and processing functions of the steel enterprise. The open-air yard causes dust pollution, which has become the main source of unorganized emission in the process of raw material production, transportation and storage. At present, with the increasing environmental protection efforts, the open-air yard is facing great pressure and has been changed to a fully enclosed storage mode. The enclosed yard can effectively reduce the pollution to the surrounding environment, and has the characteristics of large storage capacity per unit area, small material loss and easy material classification and storage.

[0003] The material shed of the enclosed yard is generally a large-span net shell structure, with a single-span width of more than 90m and a two-span arch width of more than 180m. The foundation of the material shed is sensitive to settlement and horizontal deformation. The foundation deformation is transmitted to the net shell members through the columns, increasing the additional stress of the members, and even reaching the over-stress state and damaging the net shell structure, especially in the case of wind load and snow load superposition. The large area and large load of the mineral material stacking area generate horizontal thrust and deformation on the net shell foundation, affecting the safety of the foundation and the net shell, especially in the construction of the raw material yard on deep soft soil foundation. Generally, the foundation needs to be treated to meet the bearing capacity and deformation control requirements before stacking. The pre-set drainage channel and staged stacking preloading for drainage consolidation have become one of the most common ways to reinforce soft soil foundation. Specifically, the natural foundation is treated by stacking preloading and drainage consolidation to achieve a certain strength, and CFG piles or mixing piles are arranged in the stacking area and the material taking machine area for reinforcement. However, this treatment method has the disadvantage of long construction period, which lasts for 8 to 12 months. Therefore, a new type of double-layer raw material yard structure is needed to shorten the construction period and effectively avoid various diseases caused by ground settlement in the stacking area. SUMMARY

[0004] The present application is aimed at the above problems, and provides a double-layer raw material yard structure constructed on deep soft soil foundation and a construction method thereof. The raw material yard structure directly removes the soft soil in the natural foundation to form an underground stacking layer, which can omit the soft soil treatment process, save construction time, save land space, fully utilize the strength and bearing capacity of the foundation soil in depth, greatly improve the bearing capacity of the foundation soil, and avoid various diseases caused by ground settlement to the structure.

[0005] In order to achieve the above object, the application provides a double-layer raw material yard structure constructed on deep soft soil foundation, which comprises an underground stockpile room under the ground, an above-ground stockpile room above the ground and an artificial up-and-down passage to the underground stockpile room.

[0006] Further technical scheme of the application: a material distribution area is arranged in the middle of the above-ground stockpile room, the support columns are arranged in two rows and equidistantly distributed on the bottom surface of the material distribution area, and each support column is a cast-in-situ bored pile with a pile diameter of 1.2 m.

[0007] Preferable technical scheme of the application: the feeding conveying passage and the discharging conveying passage are arranged at the two side parts of the underground stockpile room, and a material conveying belt conveyor is arranged in each of the feeding conveying passage and the discharging conveying passage, and the material conveying belt conveyor extends into the underground stockpile room.

[0008] Preferable technical scheme of the application: the underground continuous wall and the support column are both made of reinforced concrete structure, the thickness of the underground continuous wall is 1.2 m, the bottom part of the underground continuous wall is embedded below the bottom surface of the underground stockpile room, and the embedded depth is 2 / 3 of the space height of the underground stockpile room; and the support column is connected with the underground continuous wall.

[0009] Preferable technical scheme of the application: the artificial up-and-down passage is arranged at the side surface of the above-ground stockpile room in the form of a stairwell, and the stockpile shed is made of a net shell structure.

[0010] Preferable technical scheme of the application: the second raft slab layer and the first raft slab layer are both made of reinforced concrete raft slab, and the thickness of each raft slab layer is 0.8 m; the bearing beam under the first raft slab layer is 1.2 m wide and 1.5 m high.

[0011] Preferable technical scheme of the application: the drainage ditch is made of reinforced concrete structure, the width of the drainage ditch is 0.8 m, and the depth of the drainage ditch is 1.0 m.

[0012] The application provides a construction method of a double-layer raw material yard constructed on deep soft soil foundation, and the specific steps are as follows:

[0013] (1) according to the thickness of soft soil layer, the excavation depth of underground stockyard is determined, the excavation depth reaches the bottom surface of soft soil layer or is below the bottom surface, and the thickness and embedded depth of continuous wall are determined, the embedded depth of continuous wall is 2 / 3 of the excavation depth, then two parallel underground continuous walls are started to be constructed, and the column piles are struck below the material taking machine area, the column piles are cast-in-place piles;

[0014] (2) the soil body between the two underground continuous walls is excavated, the first excavation depth is greater than the sum of the thickness of the bottom raft layer of the above-ground stockyard and the thickness of the bearing beam by at least 0.5 m, the reinforced concrete bearing beam is constructed, and the reinforced concrete raft is laid above the bearing beam, when the raft is laid, a plurality of square earth taking openings are reserved to facilitate the excavation work of the underground stockyard;

[0015] (3) after the bottom bearing beam and raft layer of the above-ground stockyard are constructed, the earth taking opening reserved in step (2) is used to continue to excavate below the raft layer constructed in step (2), the second excavation reaches the design elevation of the bottom raft layer of the underground stockyard, the gravel cushion is laid, and the reinforced concrete raft layer is poured;

[0016] (4) after the underground stockyard is excavated, the earth taking opening reserved at the bottom of the above-ground stockyard is closed, the strip-shaped foundation pit is excavated on the same side of the ground of the above-ground stockyard in the feeding and discharging directions of the underground stockyard by using the underground continuous wall support structure, the main structure of the belt corridor is poured according to a 30° slope, the main structure leads to the underground stockyard, the feeding and discharging conveying passages of the underground stockyard are formed, and the material conveying belt machines are respectively installed in the feeding and discharging conveying passages;

[0017] (6) the foundation pit is excavated at the side of the above-ground stockyard to construct the stair type artificial up-and-down passage.

[0018] The further technical scheme of the present application is that the underground continuous wall in step (1) is a reinforced concrete structure.

[0019] The preferred technical scheme of the present application is that the second excavation in step (3) uses the vertical grab bucket to cooperate with a plurality of small excavators and loading vehicles to excavate under the raft.

[0020] The invention removes the soft soil in the natural foundation, and constructs the underground raw material storage layer below the ground, omits the step of treating the soft soil, saves time; meanwhile, the raw material yard is changed from the stacking on the ground plane to the stacking in the space, saves the land occupation under the condition of the same stacking; similar to the basement structure, the strength and bearing capacity of the foundation soil itself are also fully utilized in the correction in the depth, that is, the bearing capacity is greatly improved. Generally, the depth of the basement is 13m, the correction value of the bearing capacity of the foundation in the depth is 13mx16kPa / m=208kPa, and after superposition with the inherent bearing capacity of the original foundation soil 110kPa, the bearing capacity can reach 318kPa. The double-layer structure avoids various diseases caused by the settlement of deep soft soil to the structure, and can be used in the engineering of constructing a closed large raw material yard on a complex deep soft foundation. BRIEF DESCRIPTION OF DRAWINGS

[0021] Figure 1 is a schematic diagram of the double-layer raw material yard structure of the invention;

[0022] Figure 2 is the AA section view of Figure 1 ;

[0023] Figure 3 is a schematic diagram of the ground stacking room bottom surface when the underground stacking room is excavated;

[0024] Figure 4 is a schematic diagram of the material distribution or taking.

[0025] In the figure: 1 - material shed, 2 - side column, 3 - underground continuous wall, 4 - bearing beam, 5 - support column, 6 - first raft layer, 7 - second raft layer, 8 - gravel leveling layer, 9 - underground stacking room, 10 - ground stacking room, 11 - artificial up-and-down passage, 12 - feeding conveying passage, 13 - discharging conveying passage, 14 - drainage ditch, 15 - material distribution area, 16 - material conveying belt machine, 17 - stacking, 18 - material distribution and taking machine, 19 - soil taking hole. DETAILED DESCRIPTION

[0026] The invention will be further described below in combination with the drawings and examples. The drawings of the examples are drawn in a simplified manner, and are only used for the purpose of clearly and simply illustrating the embodiments of the invention. The technical solutions shown in the drawings below are specific schemes of the embodiments of the invention, and are not intended to limit the scope of the invention. Based on the embodiments in the invention, all other embodiments obtained by those skilled in the art without creative labor fall within the scope of the invention. Figure 1

[0027] ​In the description of the present application, it should be understood that the terms "upper", "lower", "inner", "outer", "left", "right", and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, or the orientation or positional relationship commonly understood by those skilled in the art, and are only used to facilitate the description of the present application and simplify the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation of the present application.

[0028] The embodiment provides a double-layer raw material yard structure constructed on a deep soft soil foundation, specifically as shown in Figure 1 and Figure 2 The raw material yard structure includes an underground stockpile room 9 placed below the ground, an above-ground stockpile room 10 above the ground, and an artificial up-and-down passage 11 leading to the underground stockpile room 9, which is arranged on the side of the above-ground stockpile room 10 in the form of a stairwell. The underground stockpile room 9 is formed by excavating a space structure below the ground to the bottom surface of the soft soil layer after constructing an underground continuous wall 3 below the soft soil layer, the underground continuous wall 3 is made of reinforced concrete structure, the thickness of the underground continuous wall 3 is 1.2 m, the bottom is embedded below the bottom surface of the underground stockpile room 9, the embedded depth is 2 / 3 of the space height of the underground stockpile room 9, a gravel leveling layer 8 is arranged on the bottom surface of the underground stockpile room 9, a second raft layer 7 with a thickness of 0.8 m is arranged on the upper part of the gravel leveling layer 8, an inlet conveying passage 12 and an outlet conveying passage 13 are respectively arranged on both sides of the underground stockpile room 9 after the construction of the underground continuous wall 3, and extend to the ground, material conveying belt machines 16 are arranged in the inlet conveying passage 12 and the outlet conveying passage 13, and the material conveying belt machines 16 extend into the underground stockpile room 9.

[0029] The double-layer raw material yard structure constructed on a deep soft soil foundation in the embodiment is as shown in Figure 1 and Figure 2As shown, the ground stockyard 10 comprises side columns 2 on both sides and a shed 1 erected on top of the side columns 2, the side columns 2 are of reinforced concrete structure, placed above and connected with the underground continuous wall 3, and the shed 1 is of a reticulated shell structure. The bottom surface of the ground stockyard 10 is composed of a load-bearing beam 4 and a first raft layer 6 laid on the load-bearing beam 4, the load-bearing beam 4 is 1.2 m wide and 1.5 m high, and the thickness of the first raft layer 6 is 0.8 m. A material distribution area 15 is arranged in the middle of the ground stockyard 10, and support columns 5 are arranged between the ground stockyard 10 and the underground stockyard 9, the support columns 5 are arranged in two rows and equidistantly distributed on the bottom surface of the material distribution area 15, and each support column 5 is a cast-in-place pile with a pile diameter of 1.2 m. The second raft layer 7 and the first raft layer 6 are both of reinforced concrete raft, and a drainage ditch 14 with a width of 0.8 m and a depth of 1.0 m is arranged at both ends of the second raft layer 7 and the first raft layer 6, and the drainage ditch 14 is of reinforced concrete structure.

[0030] The construction process of the present application will be further described below in combination with specific embodiments. The embodiments are directed to the construction of a raw material yard in a certain area, which is composed of seven stockyards including ironmaking stockyard, No. 1-2 mixed stockyard, No. 1-4 sintering stockyard, etc. The ground stratum of the site mainly comprises artificial miscellaneous fill, mucky silty clay, silt, silty clay and silty fine sand, etc. The thickness of the artificial miscellaneous fill layer is 0.3-3.4 m, and the thickness of the mucky silty clay is 2.8-8.0 m. The specific construction steps of the double-layer raw material yard structure are as follows:

[0031] (1) Construct the basement outer wall on both sides of one span of the raw material yard: according to the calculation of earth pressure, the thickness of the underground continuous wall is 1.0 m, i.e. the excavation is to the bottom of the soft soil layer, and the excavation depth is 10.0 m. According to the empirical formula, the embedded depth of the underground continuous wall is half of the excavation depth, i.e. 5 m, so the depth of the underground continuous wall is determined to be 15.0 m. The underground continuous wall is of reinforced concrete structure, which must meet the requirements of waterproofing, anti-seepage and anticorrosion. Meanwhile, the vertical column piles are driven below the reclaimer area, which are cast-in-place piles with a pile diameter of 1.2 m.

[0032] (2) Excavate the soil body: the thickness of the first layer of reinforced concrete raft of the raw material yard structure is 700 mm, and the support beam below the raft is 1000 mm wide and 1200 mm high. In order to facilitate construction, the first excavation is to a depth of 0.5 m below the first layer of raft and support beam, and the first raft layer 6 at the bottom of the ground stockyard 10 and the support beam are constructed. The support beam is converted into a load-bearing beam in the later stage, and as shown in Figure 3 , a plurality of square soil taking openings 19 are equidistantly reserved for the excavation of the underground stockyard 9;

[0033] (3) After the bottom bearing beam and raft layer of the ground stockyard 10 are constructed, the reserved soil taking opening 19 is used to carry out secondary excavation under the raft by vertical grab bucket, several small excavators and loading vehicles, and the second excavation is carried out to the depth of 0.5 m below the raft layer of the bottom of the underground stockyard, and the gravel cushion is laid and the reinforced concrete raft layer is poured;

[0034] (4) After the underground stockyard 9 is excavated and constructed, the reserved soil taking opening 19 of the bottom of the ground stockyard 10 is closed, and the long strip foundation pit is excavated on the ground on the same side of the feeding and discharging direction of the ground stockyard 10 by using the underground continuous wall support structure, and the main structure of the belt corridor is poured according to the slope of 30°, and the feeding and discharging conveying passages 12 and 13 are formed to the underground stockyard, and the conveying belt is installed in the feeding and discharging conveying passages 12 and 13 to convey the materials, and the artificial up and down passage 11 is excavated and constructed on the side of the ground stockyard 10, and the artificial up and down passage 11 is used in the form of up and down stairs to facilitate the artificial up and down;

[0035] (5) The stair type artificial up and down passage is excavated and constructed on the side of the ground stockyard, and the construction method of the stair type artificial up and down passage is the same as that of the conventional stair type artificial passage.

[0036] After the construction of the raw material field structure is completed, the materials can be stacked on the negative layer and the first layer structures respectively, and the upper layer is stacked and taken as shown in Figure 4 , and the material distribution and taking machine 18 is driven to the material distribution area 15 to carry out the material distribution and taking work; when the lower layer is stacked, the material distribution machine can be disassembled, carried to the underground stockyard 9, then assembled and used to carry out the material distribution and taking, and the hoisting space needs to be reserved on the top plate of the underground stockyard 9.

[0037] The double-layer raw material field structure in the embodiment changes the two continuous spans in the horizontal direction and one layer in the depth direction of the stockyard structure into one span in the horizontal direction and two layers in the depth direction, which is equivalent to building a basement under the ground, and is also used for stacking materials. In the case of stacking the same materials, the land occupation is saved, the strength and bearing capacity of the foundation soil in the depth direction are fully utilized, the bearing capacity is greatly improved, various diseases caused by ground settlement to the structure are avoided, and the double-layer raw material field structure can be used in the construction of the closed large raw material field on the complex deep soft soil foundation.

[0038] The above is only a detailed description of the specific implementation scheme of the present application, and does not limit the present application, and any modification, equivalent replacement and improvement made in the design idea of the present application shall be included in the protection scope of the present application.

Claims

1. A double-layer raw material yard constructed on a deep soft soil foundation, characterized in that: The raw material yard comprises an underground stockyard (9) placed below the ground, an above-ground stockyard (10) above the ground, and a man-made up-and-down passage (11) leading to the underground stockyard (9), the underground stockyard (9) is a underground space structure formed by excavating to the bottom surface of the soft soil layer after constructing the underground continuous wall (3) below the ground to the soft soil layer, the bottom of the underground continuous wall (3) is embedded below the bottom surface of the underground stockyard (9), and the embedded depth is 2 / 3 of the space height of the underground stockyard (9); the bottom surface is paved with a broken stone leveling layer (8) and a second raft layer (7), a feeding conveying passage (12) and a discharging conveying passage (13) are respectively arranged on the two sides of the underground stockyard (9), and the feeding conveying passage (12) and the discharging conveying passage (13) respectively lead to the ground; the side columns (2) on the two sides of the above-ground stockyard (10) are respectively placed above the underground continuous wall (3), a stock shed (1) is arranged on the top of the side column (2), the bottom surface of the above-ground stockyard (10) is composed of a bearing beam (4) and a first raft layer (6) paved on the bearing beam (4), a supporting column (5) is arranged between the above-ground stockyard (10) and the underground stockyard (9), and a drainage ditch (14) is arranged at the two ends of the second raft layer (7) and the first raft layer (6); A material distribution area (15) is arranged in the middle of the above-ground stockyard (10), the supporting columns (5) are arranged in two rows and are equidistantly distributed on the bottom surface of the material distribution area (15), each supporting column (5) is a bored pile, and the pile diameter is 1.2 m; the feeding conveying passage (12) and the discharging conveying passage (13) are arranged on the two sides of the middle area of the underground stockyard (9), a material conveying belt machine (16) is arranged in the feeding conveying passage (12) and the discharging conveying passage (13), and the material conveying belt machine (16) extends into the underground stockyard (9); The construction method of the double-layer raw material yard constructed on the deep soft soil foundation is characterized by the following specific steps: (1) the excavation depth of the underground stockyard is determined according to the thickness of the soft soil layer, the excavation depth reaches the bottom surface of the soft soil layer or is below the bottom surface, the thickness and the embedded depth of the continuous wall are determined, and the embedded depth of the continuous wall is 2 / 3 of the excavation depth; then two parallel underground continuous walls are constructed, and the column piles are constructed below the material taking machine area, and the column piles are bored piles; (2) the soil between the two underground continuous walls is excavated, the first excavation depth is greater than the sum of the thickness of the raft layer at the bottom of the above-ground stockyard and the thickness of the bearing beam by at least 0.5 m, the reinforced concrete bearing beam is constructed, the reinforced concrete raft is paved above the bearing beam, and a plurality of square soil taking openings are reserved when the raft is paved to facilitate the excavation of the underground stockyard; (3) after the bottom surface bearing beam and the raft layer of the above-ground stockyard are constructed, the raft layer constructed in step (2) is continuously excavated through the reserved soil taking openings, the second excavation reaches the design elevation of the raft layer at the bottom surface of the underground stockyard, the broken stone cushion is paved, and the reinforced concrete raft layer is poured; (4) After the underground stockyard is excavated, the reserved soil taking hole on the bottom of the ground stockyard is closed, a long strip foundation pit is excavated on the same side of the ground stockyard in the feeding and discharging direction by using the underground continuous wall supporting structure, the main structure of the belt corridor is poured according to the 30° slope, the underground stockyard is accessed, the feeding and discharging conveying passages of the underground stockyard are formed, and the material conveying belt machines are respectively installed in the feeding and discharging conveying passages; (5) A stair type artificial up and down passage is excavated and constructed on the side of the ground stockyard.

2. The double-layer raw material yard constructed on deep soft soil foundation according to claim 1, characterized in that: The second raft layer (7) and the first raft layer (6) are both reinforced concrete rafts, and the thicknesses of the two are both 0.8 m; the bearing beam (4) under the first raft layer (6) is 1.2 m wide and 1.5 m high.

3. The double-layer stockyard structure constructed on deep soft soil foundation according to claim 1, characterized in that: The underground continuous wall (3) and the side column (2) are both reinforced concrete structures, and the thickness of the underground continuous wall is 1.2 m; the side column (2) is connected with the underground continuous wall (3).

4. The double-layer stockyard structure constructed on deep soft soil foundation according to claim 1, characterized in that: The artificial up and down passage (11) is arranged on the side of the ground stockyard (10) and adopts the form of a stairwell; the shed (1) adopts a reticulated shell structure.

5. The double-layer stockyard constructed on deep soft soil foundation according to claim 1, characterized in that: The drainage ditch (14) adopts a reinforced concrete structure, and the width and the depth of the drainage ditch are 0.8 m and 1.0 m respectively.

6. The double-layer stockyard constructed on deep soft soil foundation according to claim 1, characterized in that: The underground continuous wall in the step (1) is a reinforced concrete structure.

7. The double-layer stockyard constructed on deep soft soil foundation according to claim 1, characterized in that: In the step (3), the second time of excavation is performed by using a vertical grab bucket to cooperate with a plurality of small excavators and loading vehicles to excavate under the raft.

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