A construction method of a high-speed railway station building pile cap

Abstract

The application discloses a kind of high-speed railway station building's bearing platform construction method, comprising: one, pile foundation construction forming and bearing platform foundation pit excavation construction;Two, install concrete precast slab;Three, pre-paved waterproofing membrane construction;Four, solidified soil backfilling and pouring;Five, using finite element software analysis bearing platform model obtains bearing platform layered pouring construction parameter;Six, bearing platform bottom and side surface steel bar binding;Seven, temperature measuring point layout;Eight, the first time pouring and maintenance of concrete;Nine, middle steel bar binding, top steel bar binding, column reinforcement insertion and concrete secondary pouring.The application method step is simple, and design is reasonable, solve the current high-speed railway station building's bearing platform backfilling and pouring problem, and reduce construction cost.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of pile cap construction, and particularly relates to a pile cap construction method for a high-speed rail station building. BACKGROUND

[0002] With the rapid development of high-speed rails, the station building engineering structure is getting larger and larger, and many super-large components appear, and the construction quality requirement of the building engineering is relatively high, and the conventional construction mode of the large-volume pile cap cannot meet the on-site construction requirement,

[0003] At present, the pile cap is generally backfilled with soil, and in order to meet the requirement of pile cap formwork support, the soil excavation amount is extremely large, which is not only long in period and difficult, but also difficult to control the backfill quality after construction, and many construction units have to use plain concrete as the backfill material, but there are still disadvantages of high cost and difficult maintenance. In addition, the large-volume pile cap pouring exists the difficulty of surface cracks caused by temperature stress. SUMMARY

[0004] The technical problem to be solved by the application is to provide a pile cap construction method for a high-speed rail station building, which is simple in method steps and reasonable in design, solves the problems of pile cap backfilling and pouring of the current high-speed rail station building, and reduces the construction cost.

[0005] To solve the above technical problems, the technical scheme adopted by the application is that a pile cap construction method for a high-speed rail station building, characterized in that the method comprises the following steps:

[0006] Step one, pile foundation construction and pile cap foundation pit excavation construction:

[0007] Step 101, constructing a pile foundation in a to-be-constructed area; wherein the top of the pile foundation is lower than the to-be-constructed area construction surface;

[0008] Step 102, excavating a pile cap foundation pit in the to-be-constructed area; wherein the bottom of the pile cap foundation pit is lower than the pile head of the pile foundation;

[0009] Step 103, constructing a concrete cushion layer in the bottom of the pile cap foundation pit, and performing reaction-bonding type wet-paving waterproof roll material construction and concrete waterproof layer pouring on the top surface of the concrete cushion layer to form a bottom waterproof protection layer; wherein the pile head of the pile foundation penetrates through the concrete cushion layer and the bottom waterproof protection layer;

[0010] Step two, installing a prefabricated concrete slab:

[0011] installing a steel pipe frame on the bottom waterproof protection layer, and sequentially installing prefabricated concrete slabs on the four outer sides of the steel pipe frame; wherein the steel pipe frame and the pile head of the pile foundation are arranged in a staggered manner, and the cross section surrounded by the prefabricated concrete slabs is rectangular;

[0012] Step three, pre-laying waterproofing membrane construction:

[0013] Reaction bonding type wet laid waterproofing membrane is laid on the side of the prefabricated concrete slab away from the steel pipe frame to form a side waterproof layer;

[0014] Step four, solidified soil backfill pouring:

[0015] Solidified soil backfill pouring is carried out between the side wall of the pile cap foundation pit and the side waterproof layer until the top surface of the backfill is flush with the top surface of the pile cap foundation pit;

[0016] Step five, using finite element software to analyze the pile cap model to obtain pile cap layering construction parameters; wherein, the pile cap layering construction parameters include the first pouring design elevation, the second pouring design elevation and the layering interval design days;

[0017] Step six, pile cap bottom and side reinforcement binding:

[0018] Step 601, remove the steel pipe frame;

[0019] Step 602, bind the bottom reinforcement on the bottom waterproof protective layer, and the bottom reinforcement is placed on the pile head of the pile foundation;

[0020] Step 603, bind the side reinforcement along the inner side of the prefabricated concrete slab, and the spacing between the outer side of the side reinforcement and the inner side of the prefabricated concrete slab is 50mm-60mm;

[0021] Step 604, install the column bar support; wherein, the steel pipe leg of the bar support is placed on the bottom waterproof protective layer, the top of the steel pipe leg is higher than the first pouring design elevation, the top of the steel pipe leg is provided with a channel steel bracket, and the cross section surrounded by the channel steel bracket is rectangular;

[0022] Step seven, temperature measuring point layout:

[0023] Step 701, set test axes in the width center direction, the length center direction and the diagonal direction of the bottom waterproof protective layer, and set at least 4 measuring points on each test axis;

[0024] Step 702, set a temperature measuring pipe at each measuring point, and sequentially set a plurality of temperature measuring probes in the temperature measuring pipe in the height direction;

[0025] Step eight, first pouring and curing of concrete;

[0026] Step 801, first pour concrete into the foundation pit surrounded by the prefabricated concrete slab and the bottom waterproof protective layer until the first pouring design elevation is reached to form the first layer of concrete; wherein, the four corners of the first layer of concrete are provided with recesses;

[0027] Step 802, after the first layer of concrete is cured, water is stored on the surface of the first layer of concrete until the water storage height is 5cm-10cm;

[0028] Step 803, the first layer of concrete is water stored and maintained until the set maintenance time is reached; meanwhile, the temperature measuring probe measures the temperature inside the concrete to ensure that the internal and external temperature difference measured for three consecutive days is less than the design requirement value of the internal and external temperature difference;

[0029] Step nine, middle reinforcement binding, top reinforcement binding, column reinforcement insertion and secondary concrete pouring:

[0030] After the middle reinforcement binding, top reinforcement binding and column reinforcement insertion, when the designed intermittent days of layering are reached, the second pouring of concrete is carried out at the first pouring design position according to the pouring method of step eight, until the second pouring design elevation is met and maintenance is carried out, forming a pile cap.

[0031] The pile cap construction method of the high-speed rail station building described above is characterized in that: in step four, solidified soil is backfilled and poured between the inner side wall of the pile cap foundation pit and the side waterproof layer until the top surface of the backfill is flush with the top surface of the pile cap foundation pit, and the specific process is as follows:

[0032] Step A, first backfill pouring of solidified soil is carried out between the inner side wall of the pile cap foundation pit and the side waterproof layer; wherein the thickness of the first backfill pouring is 0.5m;

[0033] Step B, 20-30min after initial setting, second backfill pouring of solidified soil is carried out between the inner side wall of the pile cap foundation pit and the side waterproof layer; wherein the thickness of the second backfill pouring is not more than 2m;

[0034] Step C, 20-30min after initial setting, third backfill pouring of solidified soil is carried out between the inner side wall of the pile cap foundation pit and the side waterproof layer; wherein the thickness of the second backfill pouring is not more than 2m;

[0035] Step D, backfill pouring is carried out according to steps B and C until the top surface of the pile cap foundation pit is reached.

[0036] The pile cap construction method of the high-speed rail station building described above is characterized in that: in step five, finite element software is used to analyze the pile cap model to obtain pile cap layering pouring construction parameters, and the specific process is as follows:

[0037] Step A, a pile cap is created using a computer and finite element software to obtain a three-dimensional geometric model of the pile cap;

[0038] Step B, in the finite element analysis software, set the grid size, carry out finite element grid division to the three-dimensional geometric model of the pile cap, and generate a pile cap model; wherein the parameters of the pile cap model include material, specific heat, bulk density, thermal conductivity, convection coefficient, ambient temperature, 28-day compressive strength, elastic modulus, thermal expansion coefficient, and Poisson's ratio;

[0039] Step C, in the finite element analysis software, set the boundary conditions and loads; wherein the boundary conditions are to constrain the translational degrees of freedom of the bottom of the pile cap model in three directions, the loads include an ambient temperature of 25℃, a convection boundary is applied to the side and top surfaces of the pile cap model, the bottom of the pile cap model is fixed at a temperature of 25℃, the maximum adiabatic temperature rise in the heat source function of hydration heat is 65.52, and the constant is 1.07;

[0040] Step D, in the finite element analysis software, set the first pouring thickness, the second pouring thickness, and the layering interval days, simulate the formation of the pile cap model through the first pouring and the second pouring, and obtain the temperature cloud atlas after the first pouring simulation and the temperature cloud atlas after the second pouring simulation;

[0041] Step E, obtain the temperature peak value from the temperature cloud atlas after the first pouring simulation and the temperature cloud atlas after the second pouring simulation, if the temperature peak value meets the design temperature value, the first pouring thickness, the second pouring thickness, and the layering interval days corresponding to the temperature peak value are the first pouring design elevation, the second pouring design elevation, and the layering interval design days respectively; if the temperature peak value does not meet the design temperature value, execute Step F;

[0042] Step F, adjust the first pouring thickness, the second pouring thickness, and the layering interval days, repeat Steps D and E until the temperature peak value meets the design temperature value, and obtain the first pouring design elevation, the second pouring design elevation, and the layering interval design days.

[0043] The pile cap construction method of the high-speed rail station house has the characteristics that the bottom reinforcement in Step 602 includes a plurality of bottom longitudinal reinforcements arranged along the length direction of the bottom of the pile cap foundation pit and a plurality of bottom transverse reinforcements arranged along the length direction of the bottom longitudinal reinforcements, the length direction of the bottom longitudinal reinforcement is arranged along the length direction of the bottom of the pile cap foundation pit, the length direction of the bottom transverse reinforcement is arranged along the width direction of the bottom of the pile cap foundation pit, and the spacing between adjacent two bottom longitudinal reinforcements and the spacing between adjacent two bottom transverse reinforcements are 100mm-120mm.

[0044] The side reinforcement in step 603 includes a plurality of side longitudinal reinforcement arranged along the width direction of the prefabricated concrete slab and a plurality of side transverse reinforcement arranged along the length direction of the side longitudinal reinforcement, the length direction of the side longitudinal reinforcement is arranged along the height direction of the prefabricated concrete slab, the length direction of the side transverse reinforcement is arranged along the width direction of the side surface of the pile cap foundation pit, and the spacing between adjacent two side longitudinal reinforcement and the spacing between adjacent two side transverse reinforcement is 100mm-120mm.

[0045] The pile cap construction method of the high-speed rail station building, characterized in that: the top of the temperature measuring pipe in step 702 is provided with an upper connecting pipe, and the upper end of the upper connecting pipe is provided with an elastic rubber plug; the lowermost temperature measuring probe is located above the bottom waterproof protection layer and is 50mm away from the bottom waterproof protection layer in height, the uppermost temperature measuring probe is located below the first pouring design elevation and is 50mm away from the first pouring design elevation in height, and the height interval between adjacent two temperature measuring probes in the middle is not more than 500mm; the lower part of the temperature measuring pipe is tied with the pile cap bottom reinforcement, and the temperature measuring pipe is vertically arranged;

[0046] In step 906, the next temperature measuring pipe is connected to the temperature measuring pipe, and the specific process is as follows:

[0047] The elastic rubber plug is removed, and the next temperature measuring pipe is connected in the upper connecting pipe, and a plurality of temperature measuring probes are arranged in the height direction of the next temperature measuring pipe; wherein the lower connecting head of the next temperature measuring pipe is threadedly connected with the upper connecting pipe; wherein the bottom of the next temperature measuring pipe is open;

[0048] The pile cap construction method of the high-speed rail station building, characterized in that: in step 906, the lowermost temperature measuring probe is located above the first pouring design elevation and is 50mm away from the first pouring design elevation in height, the uppermost temperature measuring probe is located below the second pouring design elevation and is 50mm away from the second pouring design elevation in height, and the height interval between adjacent two temperature measuring probes in the middle is not more than 500mm.

[0049] The pile cap construction method of the high-speed rail station building, characterized in that: in step nine, the middle reinforcement is tied, the top reinforcement is tied, the column reinforcement is inserted, and the concrete is poured for the second time, and the specific process is as follows:

[0050] In step 901, the middle reinforcement is tied on the first layer of concrete according to the method described in step 602; wherein the end of the middle reinforcement is attached to the side reinforcement;

[0051] In step 902, the raft bottom reinforcement is tied on the construction area of the four sides of the pile cap foundation pit according to the method described in step 602; wherein the end of the raft bottom reinforcement close to the pile cap penetrates through the side reinforcement and extends above the first layer of concrete;

[0052] Step 903, according to the method described in step 602, binding the top steel bars on the top surface of the pile cap foundation pit; wherein the top steel bars pass through the side steel bars and extend above the raft bottom steel bars;

[0053] Step 904, inserting column bars on the channel steel bracket; wherein the column bars located at the four corners pass through the channel steel bracket, and the bottom of the column bars located at the four corners is bent after extending into the bottom of the middle steel bars; the top of the column bars is higher than the second pouring design elevation;

[0054] Step 905, binding stirrups on a plurality of column bars; wherein the stirrups are a plurality of, and the plurality of stirrups are arranged along the height direction;

[0055] Step 906, connecting the next temperature measuring pipe on the temperature measuring pipe, and arranging a plurality of temperature measuring probes on the next temperature measuring pipe along the height direction;

[0056] Step 907, when the layered intermittent design days are reached, the second pouring of concrete is carried out at the first pouring design according to the pouring method of step eight, until the second pouring design elevation is met and curing is carried out, to form the pile cap.

[0057] Compared with the prior art, the present application has the following advantages:

[0058] 1. The method steps of the present application are simple and reasonable in design, solving the problems of pile cap backfilling and pouring of the current high-speed railway station building, and reducing the construction cost.

[0059] 2. The bottom waterproof protective layer of the pile cap foundation pit is constructed and the steel pipe frame is installed, so that the four outer sides of the steel pipe frame are sequentially installed with prefabricated concrete slabs, and the reaction bonding type wet waterproofing membrane is laid on the side of the prefabricated concrete slab away from the steel pipe frame, so as to form a three-dimensional integrated underground backfill waterproof system through the prefabricated concrete slab and the reaction bonding type wet waterproofing membrane, facilitating subsequent solidified soil backfilling and pouring, and also satisfying the protection of the membrane surface from being punctured and other artificial damage during subsequent reinforcement construction.

[0060] 3. The present application uses premixed fluidized solidified soil for backfilling and pouring, and the effect of pile cap backfilling can reach that of plain concrete, but the cost is much lower than that of using concrete backfilling. At the same time, concentrated mixing is used during construction, and the material is in liquid state during on-site pouring, which will not produce dust pollution and is green and environmentally friendly.

[0061] 4. The present application uses finite element software to analyze the pile cap model to obtain pile cap layered pouring construction parameters, so as to carry out layered intermittent pouring through the setting of horizontal construction joints, which can effectively reduce the hydration heat of mass concrete, effectively control the cracks caused by temperature changes, fundamentally solve the problems of excessive temperature difference between the inside and outside of the concrete and excessive temperature difference between the center and surface of the concrete, and can avoid the occurrence of mass concrete cracks caused by hydration heat emission to the greatest extent.

[0062] 5. The column and reinforcing rod support of the present application is used for the middle reinforcing rod binding and column rod inserting after the first pouring and curing of the concrete, and the column rod is inserted on the channel steel bracket, the column rod at the four corners passes through the channel steel bracket, and the bottom of the column rod at the four corners bends after extending into the bottom of the middle reinforcing rod, so that the safety and stability of the reinforcing rod are ensured, and the positioning is accurate.

[0063] In summary, the method of the present application has simple steps and reasonable design, solves the problem of pile cap backfilling and pouring of the current high-speed railway station building, and reduces the construction cost.

[0064] The technical solutions of the present application will be further described in detail below by means of the drawings and examples. BRIEF DESCRIPTION OF DRAWINGS

[0065] Figure 1 It is a structural diagram of the steel pipe frame and the prefabricated concrete slab of the present application.

[0066] Figure 2 It is a structural diagram of the reinforcing rod binding of the present application.

[0067] Figure 3 It is a structural diagram of the measuring point of the present application.

[0068] Figure 4 It is a structural diagram of the temperature measuring guide pipe of the present application.

[0069] Figure 5 It is a flow chart of the present application.

[0070] BRIEF DESCRIPTION OF DRAWINGS

[0071] 1 - area to be constructed; 2 - concrete cushion layer; 3 - bottom waterproof protective layer;

[0072] 4 - steel pipe frame; 5 - prefabricated concrete slab; 6 - side waterproof layer;

[0073] 7 - solidified soil; 8 - pile cap foundation pit; 9-1 - bottom longitudinal reinforcement;

[0074] 9-2 - bottom transverse reinforcement; 9-3 - side longitudinal reinforcement; 9-4 - side transverse reinforcement;

[0075] 9-5 - middle longitudinal reinforcement; 9-6 - middle transverse reinforcement; 9-8 - raft bottom reinforcement;

[0076] 9-9 - top reinforcement; 10 - pile foundation;

[0077] 11 - channel steel bracket; 12 - steel pipe leg;

[0078] 13 - measuring point; 14-1 - temperature measuring guide pipe; 14-2 - temperature measuring probe;

[0079] 14-3 - upper connecting pipe; 14-4 - elastic rubber plug; 15 - groove;

[0080] 16 - column bar; 17 - stirrup; 18 - direct buried point. DETAILED DESCRIPTION

[0081] As Figure 1 shown, the present application is a kind of high-speed rail station platform construction method, comprising the following steps:

[0082] Step one, pile foundation construction forming and platform base pit excavation construction:

[0083] Step 101, construction forming pile foundation 10 in the area to be constructed 1;Wherein, the top of pile foundation 10 is lower than the construction surface of the area to be constructed 1;

[0084] Step 102, excavate to form platform base pit 8 in the area to be constructed 1;Wherein, the bottom of platform base pit 8 is lower than the pile head of pile foundation 10;

[0085] Step 103, construction of concrete cushion 2 in the bottom of platform base pit 8, and reaction bonding type wet waterproofing membrane construction and concrete waterproof layer pouring on the top surface of concrete cushion 2, to form bottom waterproof protection layer 3;Wherein, the pile head of pile foundation 10 passes through concrete cushion 2 and bottom waterproof protection layer 3;

[0086] Step two, install the prefabricated concrete slab:

[0087] Install steel pipe frame 4 on the bottom waterproof protection layer 3, and install prefabricated concrete slab 5 on the four outer sides of steel pipe frame 4 in turn;Wherein, steel pipe frame 4 and pile head of pile foundation 10 are staggered, and the cross section surrounded by prefabricated concrete slab 5 is rectangular;

[0088] Step three, pre-paved waterproofing membrane construction:

[0089] Reaction bonding type wet waterproofing membrane is laid on the side of prefabricated concrete slab 5 away from steel pipe frame 4 to form side waterproof layer 6;

[0090] Step four, solidified soil backfill pouring:

[0091] Solidified soil backfill pouring is carried out between the inner wall of platform base pit 8 and side waterproof layer 6, until the top surface of backfill is flush with the top surface of platform base pit 8;

[0092] Step five, use finite element software to analyze platform model to obtain platform layering construction parameters;Wherein, platform layering construction parameters include first pouring design elevation, second pouring design elevation and layering interval design days;

[0093] Step six, platform bottom and side steel bar binding:

[0094] Step 601, dismount the steel pipe frame 4;

[0095] Step 602, bind the bottom steel bars on the bottom waterproof protection layer 3, and the bottom steel bars are placed on the pile head of the pile foundation 10;

[0096] Step 603, bind the side steel bars along the inner side of the prefabricated concrete slab 5, and the spacing between the outer side of the side steel bars and the inner side of the prefabricated concrete slab 5 is 50mm-60mm;

[0097] Step 604, install the column bar support; wherein the bottom of the steel pipe leg 12 of the bar support is placed on the bottom waterproof protection layer 3, the top of the steel pipe leg 12 is higher than the first pouring design elevation, and the top of the steel pipe leg 12 is provided with a channel steel bracket 11, and the cross section surrounded by the channel steel bracket 11 is rectangular;

[0098] Step seven, temperature measuring point arrangement:

[0099] Step 701, set test axes in the center direction of the width, the center direction of the length, and the diagonal direction of the bottom waterproof protection layer 3, and set at least four measuring points 13 on each test axis;

[0100] Step 702, set a temperature measuring pipe 14-1 on each measuring point 13, and sequentially set a plurality of temperature measuring probes 14-2 in the temperature measuring pipe 14-1 along the height direction;

[0101] Step eight, first pouring and curing of the concrete;

[0102] Step 801, pour the first concrete into the foundation pit surrounded by the prefabricated concrete slab 5 and the bottom waterproof protection layer 3, until the first pouring design elevation is reached, to form a first layer of concrete; wherein the four corners of the first layer of concrete are provided with recesses 15;

[0103] Step 802, after the first layer of concrete is finally cured, water is stored on the surface of the first layer of concrete until the water storage height is 5cm-10cm;

[0104] Step 803, the first layer of concrete is water stored and cured until the set curing time is reached; at the same time, the temperature measuring probes 14-2 measure the temperature inside the concrete to ensure that the internal and external temperature difference measured for three consecutive days is less than the design requirement value of the internal and external temperature difference;

[0105] Step nine, middle steel bar binding, top steel bar binding, column bar insertion, and second pouring of the concrete:

[0106] After the middle steel bar binding, the top steel bar binding, and the column bar insertion, when the intermittent design days of the layers are reached, the second pouring of the concrete is performed at the first pouring design according to the pouring method of step eight, until the second pouring design elevation is met and curing is performed, to form a pile cap.

[0107] In this embodiment, the cured soil is backfilled and poured between the inner side wall of the bearing platform foundation pit 8 and the side waterproof layer 6 in step four until the top surface of the backfill is flush with the top surface of the bearing platform foundation pit 8, and the specific process is as follows:

[0108] Step A, the first time backfill pouring of the cured soil is carried out between the inner side wall of the bearing platform foundation pit 8 and the side waterproof layer 6; wherein the thickness of the first time backfill pouring is 0.5m;

[0109] Step B, 20-30 minutes after initial setting, the second time backfill pouring of the cured soil is carried out between the inner side wall of the bearing platform foundation pit 8 and the side waterproof layer 6; wherein the thickness of the second time backfill pouring is not more than 2m;

[0110] Step C, 20-30 minutes after initial setting, the third time backfill pouring of the cured soil is carried out between the inner side wall of the bearing platform foundation pit 8 and the side waterproof layer 6; wherein the thickness of the second time backfill pouring is not more than 2m;

[0111] Step D, backfill pouring is carried out according to steps B and C until the top surface of the bearing platform foundation pit 8 is reached.

[0112] In this embodiment, the bearing platform model is analyzed by using finite element software to obtain the bearing platform layering construction parameters in step five, and the specific process is as follows:

[0113] Step A, a bearing platform is created by using a computer and finite element software to obtain a bearing platform three-dimensional geometric model;

[0114] Step B, in the finite element analysis software, the grid size is set, the bearing platform three-dimensional geometric model is subjected to finite element grid division, and a bearing platform model is generated; wherein the parameters of the bearing platform model include material, specific heat, bulk density, thermal conductivity, convection coefficient, environmental temperature, 28-day compressive strength, elastic modulus, thermal expansion coefficient and Poisson's ratio;

[0115] Step C, in the finite element analysis software, the boundary conditions and loads are set; wherein the boundary conditions are to constrain the translational freedom degrees of the bearing platform model bottom in three directions, and the loads include an environmental temperature of 25℃, a convection boundary applied to the side and top surfaces of the bearing platform model, a fixed temperature of 25℃ at the bottom of the bearing platform model, and a maximum adiabatic temperature rise of 65.52 and a constant of 1.07 in the heat source function of hydration heat;

[0116] Step D, in the finite element analysis software, the first time pouring thickness, the second time pouring thickness and the layering interval days are set, the bearing platform model is simulated by the first time pouring and the second time pouring, and the temperature cloud map after the first time pouring simulation and the temperature cloud map after the second time pouring simulation are obtained;

[0117] Step E, obtaining the temperature peak value from the temperature cloud map after the first pouring simulation and the temperature cloud map after the second pouring simulation, if the temperature peak value meets the design temperature value, the first pouring thickness, the second pouring thickness and the layered intermittent days corresponding to the temperature peak value are the first pouring design elevation, the second pouring design elevation and the layered intermittent design days respectively; if the temperature peak value does not meet the design temperature value, step F is executed;

[0118] Step F, adjusting the first pouring thickness, the second pouring thickness and the layered intermittent days, repeating steps D and E until the temperature peak value meets the design temperature value, and obtaining the first pouring design elevation, the second pouring design elevation and the layered intermittent design days.

[0119] In the embodiment, the bottom steel bars in step 602 include a plurality of bottom longitudinal bars 9-1 arranged along the width direction of the bottom of the pile cap foundation pit 8 and a plurality of bottom transverse bars 9-2 arranged along the length direction of the bottom longitudinal bars 9-1, the length direction of the bottom longitudinal bars 9-1 is arranged along the length direction of the bottom of the pile cap foundation pit 8, the length direction of the bottom transverse bars 9-2 is arranged along the width direction of the bottom of the pile cap foundation pit 8, and the spacing between adjacent two bottom longitudinal bars 9-1 and the spacing between adjacent two bottom transverse bars 9-2 are 100mm-120mm.

[0120] The side steel bars in step 603 include a plurality of side longitudinal bars 9-3 arranged along the width direction of the prefabricated concrete slab 5 and a plurality of side transverse bars 9-4 arranged along the length direction of the side longitudinal bars 9-3, the length direction of the side longitudinal bars 9-3 is arranged along the height direction of the prefabricated concrete slab 5, the length direction of the side transverse bars 9-4 is arranged along the width direction of the side of the pile cap foundation pit 8, and the spacing between adjacent two side longitudinal bars 9-3 and the spacing between adjacent two side transverse bars 9-4 are 100mm-120mm.

[0121] In the embodiment, the top of the temperature measuring pipe 14-1 in step 702 is provided with an upper connecting pipe 14-3, the top of the upper connecting pipe 14-3 is provided with an elastic rubber plug 14-4, the lowermost temperature measuring probe 14-2 is located above the bottom waterproof protection layer 3 and the height from the bottom waterproof protection layer 3 is 50mm, the uppermost temperature measuring probe 14-2 is located below the first pouring design elevation and the height from the first pouring design elevation is 50mm, the height spacing between adjacent two temperature measuring probes 14-2 in the middle is not more than 500mm, the lower part of the temperature measuring pipe 14-1 is tied with the bottom steel bars of the pile cap, and the temperature measuring pipe 14-1 is vertically arranged.

[0122] In step 906, the next temperature measuring pipe 14-1 is connected to the temperature measuring pipe 14-1, and the specific process is as follows:

[0123] The elastic rubber plug 14-4 is removed, and the next temperature measuring pipe 14-1 is connected in the upper connecting pipe 14-3, and a plurality of temperature measuring probes 14-2 are sequentially arranged in the height direction of the next temperature measuring pipe 14-1; wherein the lower connecting head of the next temperature measuring pipe 14-1 is threadedly connected with the upper connecting pipe 14-3; wherein the bottom of the next temperature measuring pipe 14-1 is opened;

[0124] In this embodiment, the lowermost temperature measuring probe 14-2 in step 906 is located above the first pouring design elevation and is 50 mm away from the first pouring design elevation, the uppermost temperature measuring probe 14-2 is located below the second pouring design elevation and is 50 mm away from the second pouring design elevation, and the height interval of the adjacent two temperature measuring probes 14-2 in the middle is not greater than 500 mm.

[0125] In this embodiment, the middle steel bar binding, top steel bar binding, column bar inserting and concrete secondary pouring in step nine are as follows:

[0126] Step 901, according to the method described in step 602, the middle steel bar 9-7 is bound on the first layer of concrete; wherein the end of the middle steel bar 9-7 is attached to the side steel bar;

[0127] Step 902, according to the method described in step 602, the raft bottom steel bar 9-8 is bound on the construction area 1 construction surface around the pile cap foundation pit 8; wherein the end of the raft bottom steel bar 9-8 close to the pile cap penetrates the side steel bar and extends above the first layer of concrete;

[0128] Step 903, according to the method described in step 602, the top steel bar 9-9 is bound on the top surface of the pile cap foundation pit 8; wherein the top steel bar 9-9 penetrates the side steel bar and extends above the raft bottom steel bar 9-8;

[0129] Step 904, the column bar 16 is inserted on the channel steel bracket 11; wherein the column bar 16 located at the four corners penetrates the channel steel bracket 11, and the bottom of the column bar 16 located at the four corners is bent after extending into the bottom of the middle steel bar 9-7; the top of the column bar 16 is higher than the second pouring design elevation;

[0130] Step 905, the stirrup 17 is bound on the plurality of column bars 16; wherein the stirrup 17 is a plurality of, and the plurality of stirrups 17 are arranged in the height direction;

[0131] Step 906, the next temperature measuring pipe 14-1 is connected on the temperature measuring pipe 14-1, and a plurality of temperature measuring probes 14-2 are sequentially arranged in the height direction of the next temperature measuring pipe 14-1;

[0132] Step 907, when the layered intermittent design days are reached, the second pouring of concrete is carried out at the first pouring design position according to the pouring method of step eight, until the second pouring design elevation is reached and curing is carried out, to form the pile cap.

[0133] In this embodiment, the length x width x height of the pile cap three-dimensional geometric model is 1100 cm x 700 cm x 400 cm. The pile cap model has a total of 3105 nodes and 2464 units.

[0134] In this embodiment, the parameters of the pile cap model are shown in Table 1.

[0135] Table 1 Parameters of the pile cap model

[0136]

[0137] In this embodiment, the flowing solidified soil is used instead of traditional plain concrete backfill, and the use of solidifying agent, waste soil and other raw materials saves costs; the flowing solidified soil has high one-time pouring qualification rate and good pouring quality. This greatly improves work efficiency and reduces labor costs; large equipment is not needed during the solidified soil pouring construction process, which reduces mechanical costs; after the pouring construction is completed, the pre-mixed flowing solidified soil has high strength, which reduces the maintenance costs in the later period; in terms of environmental benefits, the use of solidified soil can effectively reduce the development of resources.

[0138] In this embodiment, the flowing solidified soil includes water, a solidifying agent and soil, and the weight ratio of the water, the solidifying agent and the soil is 2.00:1.00:5.75. In this embodiment, the soil can be excavated soil.

[0139] In this embodiment, the curing time is set to 3-5 days, which is less than the layered intermittent design days.

[0140] In this embodiment, in actual use, the side walls of the foundation pit 8 are inclinedly arranged, so that the cross section of the bottom of the foundation pit 8 is smaller than the cross section of the opening at the top of the foundation pit 8.

[0141] In this embodiment, in actual use, the thickness of the concrete waterproof layer is 5-6 cm.

[0142] In this embodiment, in actual use, the top of the reaction-bonding type wet-laid waterproof coiled material laid on the side of the prefabricated concrete slab 5 away from the steel pipe frame 4 is bent and extended to the top of the side of the prefabricated concrete slab 5 close to the steel pipe frame 4.

[0143] In this embodiment, in actual use, the internal and external temperature difference design requirement value is 25℃; the internal and external temperature difference refers to the difference between the maximum temperature inside the concrete and the minimum temperature of the external environment.

[0144] In the embodiment, in actual use, the additional reinforcing layer of the waterproof coiled material is arranged at the junction of the flat surface of the prefabricated concrete slab 5, the female and male corners and the like.

[0145] In the embodiment, in actual use, the pile body surface of the pile foundation 10 is treated with polymer cement mortar, and the junction of the pile body surface of the pile foundation 10 and the waterproof coiled material is treated with a 50 mm circular arc corner sealant.

[0146] In the embodiment, in actual use, the four channel steel brackets 11 are arranged in a rectangular shape.

[0147] In the embodiment, in actual use, the channel steel bracket 11 includes a U-shaped channel steel and a positioning plate arranged in the U-shaped channel steel, the bottom surface of the positioning plate is attached to the inner bottom surface of the U-shaped channel steel, the top surface of the positioning plate is flush with the top surface of the U-shaped channel steel, a plurality of positioning holes for inserting the column bars 16 are arranged in the positioning plate along the length direction, and the positioning holes penetrate the positioning plate so that the bottom surface of the column bar 16 is attached to the inner bottom surface of the U-shaped channel steel.

[0148] The end of the U-shaped channel steel is provided with a through hole for the bottom of the column bar 16 located at the four corners.

[0149] In the embodiment, in actual use, the middle steel bars include a plurality of middle longitudinal bars 9-5 arranged along the width direction of the bearing platform foundation pit 8 and a plurality of middle transverse bars 9-6 arranged along the length direction of the middle longitudinal bars 9-5.

[0150] In the embodiment, in actual use, the direct-buried point 18 is further arranged, and the temperature measuring probe is directly buried for comparison with the catheter temperature measurement to avoid large catheter temperature measurement error.

[0151] In summary, the method of the present application has simple steps and reasonable design, solves the problem of bearing platform backfilling and pouring of the current high-speed rail station building, and reduces the construction cost.

[0152] The above is only a preferred embodiment of the present application, and does not limit the present application in any way. Any simple modification, change and equivalent structural change made according to the technical essence of the present application to the above embodiment are still within the protection scope of the technical solution of the present application.

Claims

1. A method for constructing the foundation of a high-speed railway station building, characterized in that, The method includes the following steps: Step 1: Pile foundation construction and excavation of the pile cap pit: Step 101: Construct a shaped pile foundation (10) in the area to be constructed (1); wherein the top of the pile foundation (10) is lower than the construction surface of the area to be constructed (1); Step 102: Excavate a foundation pit (8) in the area to be constructed (1); wherein the bottom of the foundation pit (8) is lower than the pile head of the pile foundation (10); Step 103: Construct a concrete cushion layer (2) at the bottom of the foundation pit (8), and carry out reactive bonding wet-laid waterproof membrane construction and concrete waterproof layer pouring on the top surface of the concrete cushion layer (2) to form a bottom waterproof protective layer (3); wherein, the pile head of the pile foundation (10) passes through the concrete cushion layer (2) and the bottom waterproof protective layer (3). Step 2: Install precast concrete slabs: A steel pipe frame (4) is installed on the bottom waterproof protective layer (3), and precast concrete slabs (5) are installed on the four outer sides of the steel pipe frame (4) in sequence; wherein the steel pipe frame (4) and the pile heads of the pile foundation (10) are staggered, and the cross section enclosed by the precast concrete slabs (5) is rectangular. Step 3: Pre-laying of waterproof membrane: A reactive adhesive wet-laid waterproof membrane is laid on the side of the precast concrete slab (5) away from the steel pipe frame (4) to form a side waterproof layer (6). Step 4: Backfilling and pouring of solidified soil: Backfilling and pouring of solidified soil (7) between the inner wall of the foundation pit (8) and the side waterproof layer (6) until the top surface of the backfill is flush with the top surface of the foundation pit (8); Step 5: Use finite element software to analyze the foundation model and obtain the construction parameters for layered pouring of the foundation; among which, the construction parameters for layered pouring of the foundation include the first pouring design elevation, the second pouring design elevation, and the design number of days for inter-layer intervals; Step Six: Binding of Reinforcing Bars at the Bottom and Sides of the Foundation: Step 601: Dismantle the steel pipe frame (4); Step 602: Tie bottom reinforcing bars on the bottom waterproof protective layer (3), and place the bottom reinforcing bars on the pile head of the pile foundation (10); Step 603: Tie side reinforcement bars along the inner side of the precast concrete slab (5); Step 604: Install column insert support; wherein, the bottom of the steel pipe leg (12) of the insert support is placed on the bottom waterproof protective layer (3), the top of the steel pipe leg (12) is higher than the first pouring design elevation, and a channel steel bracket (11) is provided on the top of the steel pipe leg (12), and the cross section enclosed by the channel steel bracket (11) is rectangular; Step 7: Temperature Measurement Point Setup Step 701: Set test axes along the width center direction, the length center direction, and the diagonal direction on the bottom waterproof protective layer (3), and set at least 4 test points (13) on each test axis; Step 702: Set a temperature measuring conduit (14-1) at each measuring point (13), and set multiple temperature measuring probes (14-2) in the temperature measuring conduit (14-1) along the height direction. Step 8: First pouring and curing of concrete; Step 801: Pour concrete for the first time into the foundation pit enclosed by the precast concrete slab (5) and the bottom waterproof protective layer (3) until the first pouring design elevation is reached to form the first layer of concrete; wherein, the four corners of the first layer of concrete are reserved with grooves (15). Step 802: After the first concrete layer has set, water is stored on the surface of the first concrete layer until the water level is 5cm to 10cm. Step 803: The first layer of concrete is water-cured until the set curing time is reached; at the same time, the temperature probe (14-2) measures the temperature inside the concrete to ensure that the internal and external temperature difference measured for three consecutive days is less than the design requirement value. Step Nine: Binding of middle reinforcement, binding of top reinforcement, insertion of column reinforcement and secondary concrete pouring: After the middle reinforcement is tied, the top reinforcement is tied, and the column reinforcement is inserted, when the design number of days for layered intervals is reached, the second pour of concrete is carried out at the first pouring design location according to the pouring method in step eight, until the second pouring design elevation is met and curing is carried out to form the foundation. Step nine, including the binding of the middle reinforcement, binding of the top reinforcement, insertion of column reinforcement, and secondary concrete pouring, involves the following specific processes: Step 901: Following the method described in step 602, tie the central reinforcing bar (9-7) onto the first layer of concrete; wherein the end of the central reinforcing bar (9-7) is attached to the side reinforcing bar; Step 902: According to the method described in step 602, tie the bottom reinforcement bars (9-8) of the raft foundation (8) on the construction surface of the construction area (1) around the foundation pit (8); wherein, the end of the bottom reinforcement bar (9-8) of the raft foundation (9-8) near the foundation passes through the side reinforcement bars and extends into the top of the first layer of concrete. Step 903: According to the method described in step 602, tie the top reinforcement (9-9) on the top surface of the foundation pit (8); wherein the top reinforcement (9-9) passes through the side reinforcement and extends above the bottom reinforcement (9-8) of the raft slab; Step 904: Insert column reinforcement bars (16) into the channel steel bracket (11); wherein, the column reinforcement bars (16) located at the four corners pass through the channel steel bracket (11), and the bottom of the column reinforcement bars (16) located at the four corners extends into the bottom of the middle reinforcement bar (9-7) and then bends; the top of the column reinforcement bars (16) is higher than the second pouring design elevation; Step 905: Tie stirrups (17) to multiple column reinforcement bars (16); wherein there are multiple stirrups (17), and the multiple stirrups (17) are arranged along the height direction; Step 906: Connect the next temperature measuring tube (14-1) to the temperature measuring tube (14-1), and install multiple temperature measuring probes (14-2) sequentially along the height direction on the next temperature measuring tube (14-1). Step 907: When the number of intermittent design days for the layered structure is reached, the concrete is poured a second time at the first pouring design location according to the pouring method in Step 8, until the second pouring design elevation is met and the concrete is cured to form the foundation.

2. The construction method for the foundation of a high-speed railway station building according to claim 1, characterized in that: In step four, solidified soil is backfilled and poured between the inner wall of the foundation pit (8) and the side waterproof layer (6) until the top surface of the backfill is flush with the top surface of the foundation pit (8). The specific process is as follows: Step A: The first backfilling of solidified soil is carried out between the inner wall of the foundation pit (8) and the side waterproof layer (6); the thickness of the first backfilling is 0.5m. Step B: After 20 to 30 minutes of initial setting, the solidified soil is poured for the second time between the inner wall of the foundation pit (8) and the side waterproof layer (6); the thickness of the second backfill pouring shall not exceed 2m. Step C: After 20 to 30 minutes of initial setting, the solidified soil is poured for the third time between the inner wall of the foundation pit (8) and the side waterproof layer (6); the thickness of the second backfill pouring shall not exceed 2m. Step D: Backfill and pour according to steps B and C until the backfill reaches the top surface of the foundation pit (8).

3. The construction method for the foundation of a high-speed railway station building according to claim 1, characterized in that: Step five involves using finite element analysis software to analyze the foundation model and obtain the construction parameters for layered pouring of the foundation. The specific process is as follows: Step A: Use a computer and finite element software to create the foundation, and obtain a three-dimensional geometric model of the foundation; Step B: In the finite element analysis software, set the mesh size and perform finite element mesh generation on the three-dimensional geometric model of the foundation to generate the foundation model; the parameters of the foundation model include material, specific heat, bulk density, thermal conductivity, convection coefficient, ambient temperature, 28-day compressive strength, elastic modulus, coefficient of thermal expansion and Poisson's ratio. Step C: In the finite element analysis software, set the boundary conditions and loads; among them, the boundary conditions are to constrain the translational degrees of freedom of the bottom of the foundation model in three directions, the loads include an ambient temperature of 25℃, convective boundaries applied to the sides and top of the foundation model, a fixed temperature of 25℃ at the bottom of the foundation model, and the maximum adiabatic temperature rise of 65.52 and the constant of 1.07 in the heat source function of hydration heat. Step D: In the finite element analysis software, set the thickness of the first pour, the thickness of the second pour, and the number of days between layers. The foundation model is formed by simulating the first and second pours, and the temperature cloud map after the first pour simulation and the temperature cloud map after the second pour simulation are obtained. Step E: Obtain the temperature peak from the temperature cloud map after the first pouring simulation and the temperature cloud map after the second pouring simulation. If the temperature peak meets the design temperature value, the first pouring thickness, the second pouring thickness, and the number of days of inter-layer interval corresponding to the temperature peak are the first pouring design elevation, the second pouring design elevation, and the number of days of inter-layer interval, respectively. If the temperature peak does not meet the design temperature value, proceed to step F. Step F: Increase or decrease the thickness of the first pour, the thickness of the second pour, and the number of days between pours. Repeat steps D and E until the peak temperature meets the design temperature value, and obtain the design elevation of the first pour, the design elevation of the second pour, and the design number of days between pours.

4. The construction method for the foundation of a high-speed railway station building according to claim 1, characterized in that: The bottom reinforcement in step 602 includes multiple bottom longitudinal bars (9-1) arranged along the width direction of the bottom of the foundation pit (8) and multiple bottom transverse bars (9-2) arranged along the length direction of the bottom longitudinal bars (9-1). The length direction of the bottom longitudinal bars (9-1) is arranged along the length direction of the bottom of the foundation pit (8), and the length direction of the bottom transverse bars (9-2) is arranged along the width direction of the bottom of the foundation pit (8). The spacing between two adjacent bottom longitudinal bars (9-1) and the spacing between two adjacent bottom transverse bars (9-2) is 100mm to 120mm. The side reinforcement in step 603 includes multiple side longitudinal bars (9-3) arranged along the width direction of the precast concrete slab (5) and multiple side transverse bars (9-4) arranged along the length direction of the side longitudinal bars (9-3). The length direction of the side longitudinal bars (9-3) is arranged along the height direction of the precast concrete slab (5), and the length direction of the side transverse bars (9-4) is arranged along the width direction of the side of the foundation pit (8). The spacing between two adjacent side longitudinal bars (9-3) and the spacing between two adjacent side transverse bars (9-4) are 100mm to 120mm.

5. A method for constructing a pier cap for a high-speed railway station building according to claim 1, characterized in that: In step 702, the top of the temperature measuring conduit (14-1) is provided with an upper connecting pipe (14-3), and the top of the upper connecting pipe (14-3) is provided with an elastic rubber stopper (14-4); the lowest temperature measuring probe (14-2) is located above the bottom waterproof protective layer (3) and is 50mm away from the bottom waterproof protective layer (3); the highest temperature measuring probe (14-2) is located below the first pouring design elevation and is 50mm away from the first pouring design elevation; the height distance between two adjacent temperature measuring probes (14-2) in the middle is not greater than 500mm; the lower part of the temperature measuring conduit (14-1) is tied to the bottom reinforcement of the foundation, and the temperature measuring conduit (14-1) is vertically arranged; In step 906, the next temperature measuring tube (14-1) is connected to the temperature measuring tube (14-1). The specific process is as follows: Remove the elastic rubber stopper (14-4) and connect the next temperature measuring tube (14-1) to the upper connecting tube (14-3). Install multiple temperature measuring probes (14-2) sequentially along the height direction on the next temperature measuring tube (14-1). The lower connector of the next temperature measuring tube (14-1) is threadedly connected to the upper connecting tube (14-3). The bottom of the next temperature measuring tube (14-1) is open.

6. A method for constructing a pier cap for a high-speed railway station building according to claim 5, characterized in that: In step 906, the lowest temperature probe (14-2) is located above the first pouring design elevation and is 50mm above the first pouring design elevation. The highest temperature probe (14-2) is located below the second pouring design elevation and is 50mm above the second pouring design elevation. The height distance between two adjacent temperature probes (14-2) in the middle is no more than 500mm.

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