639 results about "Pile cap" patented technology

The invention provides a reverse self-balancing pile foundation bearing capacity detection method based on prefabricated steel pipe piles, and relates to the technical field of pile foundation detection, and the method comprises the steps that the assembled prefabricated steel pipe piles are constructed at preset elevation positions of a target test field; obtaining first record data and second record data; on the basis of the first recorded data and the second recorded data, the total compressive bearing capacity and the total uplift bearing capacity of the prefabricated steel pipe pile are obtained through calculation according to a reverse self-balancing method; wherein a pile body load box in the loading pile body section is used for loading, the upper pile body and the lower pile body are driven to deform oppositely, and at least the stress of the pile body load box and the opposite displacement of the pile body are recorded as first record data; and a pile top load box in the pile cap loading section is loaded, the upper pile body and the lower pile body are driven to deform oppositely, and at least the stress of the pile top load box and the opposite displacement of the pile body are recorded as second record data. The method for detecting the bearing capacity of the pile foundation is simpler, more efficient and quicker.

The invention provides a reverse hanging bottom die structure for wharf cast-in-place pile cap construction and a mounting method of the reverse hanging bottom die structure, and belongs to the technical field of wharf construction. The reverse hanging bottom die structure comprises a steel pipe pile, a stand column support arranged on the steel pipe pile, a transverse steel carrying pole arranged on the stand column, a hanging rod system, a limiting system, a supporting main beam structure and a die frame used for pile cap pouring. The supporting performance of the steel pipe cast-in-place pile is fully utilized, the structural steel structure is used for building the reverse hanging bottom die supporting structure for the cast-in-place pile cap, the defects of a welding construction technology of a traditional bracket supporting system are overcome, the supporting structure facilitating cast-in-place construction of the pile cap is provided, and the construction efficiency of a wharf cast-in-place project is effectively improved.

The invention relates to the technical field of complex geology pile releasing construction methods based on the BIM technology, and discloses a construction method named as a complex geology pile releasing construction method based on the BIM technology. The method aims at solving the problems of design and construction disjunction, insufficient risk pre-control, low resource utilization rate and the like caused by geological information dimension reduction processing and construction process static management in the prior art. The method is characterized by comprising the following steps: constructing a multi-source heterogeneous geological information full-parameterization three-dimensional attribute body model, and carrying out integrated simulation optimization design on a single-group pile cap based on the model; and sensing construction parameters in real time to dynamically correct the geologic model, so as to generate a self-adaptive construction control instruction and high-precision lofting data. By the adoption of the technical scheme, the safety, economical efficiency and environment friendliness of pile foundation engineering can be remarkably improved.

Disclosed in the present invention are high-rise pile cap equipment under a horizontal load and a centrifuge test method for foundation bearing characteristics thereof. The equipment comprises a model box, a sand layer, a model pile cap, at least eight model piles, a horizontal loading device, at least two laser displacement sensors, an axial force sensor, and a plurality of strain gauges. The method comprises: S1, performing one-way horizontal loading on high-rise pile cap equipment under a horizontal load to obtain an ultimate foundation bearing capacity situation, a model pile body axial force distribution situation, a pile foundation axial force comparison situation, a model pile body bending moment distribution situation, and a model pile body bending moment comparison situation of the equipment; and S2, performing one-way variable amplitude cyclic loading on the high-rise pile cap equipment under the horizontal load to obtain a foundation displacement situation, an effect of the number of cycles on foundation stiffness, an effect of a cyclic load amplitude on the foundation stiffness, and a foundation inclination situation. In this way, the foundation design of the high-rise pile cap can be optimized, and a basis and a reference for evaluating safety of foundation long-term service are provided.

The invention relates to an overall modular prefabricated assembly type high-pile wharf structure and an assembling method. The structure comprises an upper structure main module part, an upper structure secondary module part, a pile cap module part, a node connecting part, a pile foundation part and an ancillary facility part. The upper structure main module part and the upper structure secondary module part are arranged in a staggered mode in the longitudinal direction of a wharf, the pile cap module part is located on the lower portion of the upper structure main module part, the pile foundation part is located on the lower portions of the upper structure main module part and the pile cap module part, and the node connecting part is connected with all modules. And the subsidiary facility part is mounted on the upper structure main module part and the upper structure secondary module part. The upper structure is composed of multiple sets of standardized integrally prefabricated modules, the number of connecting joints of components and the field workload can be greatly reduced, the assembly rate of the high-pile wharf is increased, large-scale crane ship machine equipment is fully utilized, the labor cost is saved, the dependence of engineering construction on the construction window period is reduced, the construction risk is reduced, and the construction efficiency is improved. Construction is rapid, and economic cost is low.

The invention relates to the technical field of wind power, and discloses a lattice type foundation for a wind power tower and a construction method thereof.The foundation comprises a plurality of bearing platforms, and a cross beam is fixedly connected between every two adjacent bearing platforms; a lattice type wind power tower column can be erected on the upper side of the bearing platform; an embedded pipe is reserved in the center of any bearing platform and used for penetration of a prestressed steel strand, and the prestressed steel strand can be fixed to the top face of the tensioning cavity; a tensioning cavity is formed in the bottom surface of any bearing platform and can be used as a prestressed steel strand tensioning or anchoring operation space; any bearing platform is provided with a pre-stressed anchor bolt assembly, and the pre-stressed anchor bolt assembly is suitable for being fixed to a lattice type wind power tower column. The multiple bearing platforms are adopted for providing support for fixing of the lattice type wind power tower, compared with a fan foundation of a traditional cylinder type tower, the land acquisition area can be remarkably saved, the material cost is reduced, and the wind power tower foundation is suitable for various terrain environments.

The invention provides a composite pile foundation structure for road surface rigidity optimization of a road transition section and a design and use method of the composite pile foundation structure, and relates to the technical field of composite pile foundations. The composite pile foundation structure can be applied to an embankment foundation and a bridge abutment pile foundation and comprises a bearing platform, a pile cap, a gasket, an elastic composite plate, replaceable filler, a pile and a pile end self-adaptive deformer. The design and use method of the bridge abutment pile foundation is guided by the load settlement characteristic of the butted roadbed, and the design and use method of the embankment composite pile foundation is guided by the settlement control standard. Design variables comprise the pile length, the pile diameter, the pile number, the compression thickness of the elastic composite plate, the arrangement depth of the replaceable filler, the limit pile side friction resistance of the replaceable filler and the compression modulus of the replaceable material, the structure can optimize the overall rigidity of the road surface on one side of the abutment, the phenomenon of bump of the abutment is effectively avoided, zero-differential settlement is achieved theoretically, and the construction efficiency is improved. And the settlement index can be controlled in the application of an embankment foundation.

The invention relates to the construction technology of a hoop bottom die, and discloses a hoop bottom die integrated quick-mounting system which comprises a bottom die plate arranged on the outer side of the end of a vertical pile, and the bottom die plate is used for side die erecting and pouring forming positioning of a vertical pile cap; the main beam and the secondary beam are fixed to the bottom of the bottom formwork, first transverse rib plates and second transverse rib plates are fixed to the main beam and the secondary beam respectively, and a fastening and locking buckle assembly is arranged between the first transverse rib plates with the ends in butt joint; the hoop body is arranged at the end of the vertical pile in a sleeving mode through a bolt, hoop pressure-bearing ribs used for bearing and supporting the bottom formwork and the main beam are arranged on the side of the hoop body, and a hoop guide chain which is integrally detached in a hoisting mode is further arranged between the outer side of the hoop body and the secondary beam. According to the hoop and bottom die integrated quick assembly system, bottom die integrated quick assembly and disassembly construction of double-pile and single-pile cap construction operation can be achieved, secondary bottom disassembly during disassembly is not needed, and the die erecting and pouring efficiency of pile cap construction is improved.

The present invention relates to the technical field of prefabricated elevated stations. Disclosed are a self-balancing modular fully-prefabricated elevated station transition structure construction method and a structure. The construction method comprises the following steps: constructing precast pipe piles and a precast pile cap; executing concrete backfilling; installing a pier column and connecting same to the pile cap; installing a Y-pier cap for executing a connection; installing a precast middle cap beam and precast side cap beams; installing precast steel tubular columns; installing top overhanging precast reinforced concrete cap beams and a precast reinforced concrete middle cross beam; hoisting and installing precast platform slabs and precast arched platform headwalls; installing precast straddle monorail track beams; and installing a precast steel structure canopy. By using the dual columns to achieve an overhead layer and an upper structure, the present invention reduces the absolute overhanging length, improves the performance of the structure under stress, and reduces the sectional dimensions of components, thus saving the floor area of the pier column to the utmost extent, enhancing the applicability of station structures in a wider range of various urban environments, and improving the universality of the structure.

The invention discloses a screw-in type environment-friendly steel pipe pile with tip blades and a construction method. The screw-in type environment-friendly steel pipe pile comprises a steel pipe pile body, a pile cap fixed to the steel pipe pile body and a spinning driving device driving the steel pipe pile body to rotate downwards, and the pile cap is installed at the pile back position of the steel pipe pile body and driven by the spinning driving device; a tip blade is mounted at the pile tip position of the steel pipe pile, covers the pile tip position of the steel pipe pile, and comprises two semi-doughnut-shaped steel plates; the two semi-doughnut-shaped steel plates are arranged on the periphery of the steel pipe pile in a V shape; the steel plates with the semi-doughnut-shaped tip blades are arranged on the periphery of the steel pipe pile and welded in a V-shaped intersection mode, so that a wider stress surface can be formed when the pile tip enters a soil layer, the pressure of a soil body is dispersed, the soil body is effectively broken through through the gradual rotary cutting effect, the penetrating power of the pile is improved, and the construction efficiency is improved. And the situation that the construction speed is reduced or the pile body deflects due to the fact that large resistance occurs when the pile tip of the steel pipe pile makes contact with a hard soil layer is avoided.

The embodiment of the invention provides a critical height calculation method for a pile cap beam supporting type embankment. The vertical stress of the pile cap beam supporting type embankment at the given depth is calculated by utilizing a vertical stress calculation formula by obtaining soil filling parameters, pile distribution design parameters and roadbed top surface design load of the pile cap beam supporting type embankment. The method comprises the following steps: obtaining soil filling parameters, pile distribution design parameters, roadbed top surface design load and actual soil filling height of a pile cap beam supporting type embankment, calculating by utilizing a critical height calculation formula to obtain a theoretical critical height of an equal sinking surface, and correcting the theoretical critical height of the equal sinking surface in combination with the actual soil filling height of the pile cap beam supporting type embankment. And obtaining the actual critical height of the equal sinking surface. According to the method, the equivalent sinking face boundary height is related to the filling parameters and pile arrangement design parameters of the embankment and is also positively related to the actual filling height of the embankment and the design load of the top face of the roadbed, so that the calculation of the equivalent sinking face boundary height is more accurate.

The invention discloses a device and a method for measuring the pile body stress of a rotary excavating implanted pile. The device comprises a composite pile inner core, a composite pile outer core, an inner core monitoring unit, an outer core monitoring unit and a bearing platform, the inner core monitoring unit is a first optical fiber string which is formed by connecting a plurality of first high-precision strain sensors in series in a segmented encryption manner, and the first optical fiber string is arranged in a channel formed in the inner core pile body of the composite pile; the outer core detection unit is a second optical fiber string formed by connecting a plurality of second high-precision strain sensors in series in a segmented encryption manner and is mounted in the composite pile outer core, and after mounting is completed, the first optical fiber string and the second optical fiber string are in one-to-one correspondence; the inner core monitoring unit and the outer core monitoring unit are both connected with the fiber bragg grating acquisition instrument and transmit acquired sensor data to a control center for pile body stress measurement; the bearing platform is simultaneously connected with the top of the inner core and the top of the outer core to eliminate stress lag of the outer core of the composite pile; a hole is formed in the center of the bearing platform and used for allowing a pile end settlement testing pipe to penetrate through and providing a pile end monitoring channel.

The utility model discloses an inclined column template support frame for cast-in-place of a concrete beam, which is characterized in that a vertical steel pipe upright post and an inclined steel pipe upright post are fixedly arranged on a bearing platform by utilizing bearing platform anchor bolts, and the vertical steel pipe upright post and the inclined steel pipe upright post are pulled into a whole by a horizontal pull rod along the direction of a bridge; the inclined steel pipe stand columns at the corresponding positions in the single span are connected into a whole through corner connectors and horizontal cross rods. The unloading blocks are arranged on the top faces of the vertical steel pipe stand columns and the top faces of the corner connectors respectively. A bearing beam is placed on the top face of the unloading block in the transverse bridge direction, a bailey beam is arranged on the top face of the bearing beam in the bridge direction, a distribution beam is placed on the top face of the bailey beam in the transverse bridge direction, and the batter post formwork supporting frame for concrete beam cast-in-place is formed. The bearing platform is fully used as a supporting point, the inclined steel pipe stand columns are arranged to share the upper load, a strip-shaped foundation does not need to be additionally arranged, construction cost is saved, the spanning capacity of the support is greatly improved, and the support is a preferable scheme for spanning rivers, roads and bridge sites in a large-span mode when the geological environment is poor.

The invention relates to the technical field of wind power towers, and discloses a concrete-filled steel tube truss type hybrid wind power tower which comprises a tower drum, a plurality of steel tube beams and a plurality of steel tube beams. The truss unit is suitable for supporting the tower drum; the transition unit is arranged between the tower drum and the truss unit so as to connect the tower drum with the truss unit; the bearing platform unit is arranged at the end, away from the tower drum, of the truss unit and suitable for bearing the truss unit; the truss unit comprises at least one pipe body, and concrete is poured in the pipe body. And the constraint stranded wires are tensioned in the axial direction of the pipe body and anchored to the transition unit and the bearing platform unit correspondingly, and the constraint stranded wires are at least arranged outside the pipe body. According to the concrete-filled steel tube truss type hybrid wind power tower, the constraint stranded wires are arranged outside the tube body, the situation that the cable penetrating process is complex and cannot be observed is avoided, the situation that the constraint stranded wires are mutually wound in the cable penetrating process is avoided, constructors can conveniently and directly observe the tensioning state outside, and it is ensured that prestress is accurately applied.

The present invention relates to a cross-shaped hybrid wind turbine foundation and a construction method thereof. The cross-shaped hybrid wind turbine foundation comprises a pile cap (1) is cast of reinforced concrete in the shape of a inverted drum, consisting of an outer cylinder (9), an inner cylinder (10), and radial walls (11) arranged radially on the outer surface of the inner cylinder (10) to connect the inner cylinder (10) with the outer cylinder (9), forming a integrated rigid slab. A slab (12) covers the top surface of the pile cap (1), creating enclosed chambers between the slab (12), the outer cylinder (9), the inner cylinder (10), and the radial walls (11), allowing for vacuum suction when placing the pile cap (1) on the seabed ground; a adapter tower (2) is connected to the top surface of the pile cap (1); an upper pile segment (3) is connected to the bottom surface of the pile cap (1), and a lower pile segment (4) is inserted inside the upper pile segment (3); a upper anchored wire ropes (6) connects the pile cap (1) to the upper end of the adapter tower (2), and a lower anchored wire ropes (5) connects the pile cap (1) to the upper pile segment (3).

The present invention provides a fully prefabricated and assembled bridge, characterized in that: from top to bottom, the bridge successively includes main girders, cap beams, bridge piers, pile caps, and pile foundations, all of which are constructed by means of factory prefabrication and on-site assembly. Among them, the main girders and the cap beams are connected by bearings, and the cap beams and the bridge piers are connected by a connecting device composed of cap beam embedded steel plates, cap beam cast steel parts, pier top column surface sliding plates, pier top cast steel parts, pier top embedded steel plates, pier top steel bars, and pier top nuts. The bridge piers and the pile caps are connected by a connecting device composed of pile cap embedded parts, pier bottom embedded parts, pier bottom steel bars, and pier bottom nuts. The pile caps and the pile foundations are connected by bearings. The present invention has clear force transmission and convenient construction, realizes the full prefabrication, assembly, construction, and demolition of the bridge structure, and can be widely applied to the rapid construction and demolition projects of bridges.

The invention discloses a trestle-free rapid assembling and disassembling construction method for an offshore high-rise pile cap steel hanging box. The trestle-free rapid assembling and disassembling construction method comprises the following steps that S1, the steel hanging box is machined in a factory and pre-assembled; s2, transporting the steel hanging box to an assembling platform at a bridge site, and performing total assembling on the steel hanging box and the prefabricated bottom plate through connecting bolts; s3, hoisting the steel hoisting box to the pier position through a crane ship, and mounting the steel hoisting box at the pier position; s4, after the lower portion of the steel hanging box is in place, a blocking steel plate and a shear bracket are welded, and the shear bracket is located between the blocking steel plate and the steel pipe pile; s5, bottom sealing concrete is poured; s6, a bearing platform is poured; and S7, the hanging box is dismantled. A factory-like and modular process is adopted for the steel hanging box, after the river steel-concrete combined cofferdam is modularly machined in a factory, the steel-concrete combined cofferdam is generally spliced on an offshore splicing platform, then the steel-concrete combined cofferdam is hoisted in place at a time through a large crane ship, the construction efficiency is greatly improved, meanwhile, a temporary trestle is omitted, the overall hoisting technology of the crane ship is utilized, and the construction cost is reduced. The occupation on channels and the dependence on large equipment are reduced, and the construction cost is reduced.

The invention relates to the technical field of wharf structures, and discloses a wharf structure reinforced by basalt fiberboards, which comprises a pile foundation, a pile cap mounted at the top of the pile foundation, a prefabricated cross beam mounted at the top of the pile cap and a panel mounted at the top of the cross beam, an insertion groove for insertion of the insertion plate is prefabricated in the top of the pile cap, a first prefabricated hole is prefabricated in the insertion plate, second prefabricated holes are prefabricated in the two sides of the insertion groove, a split bolt is arranged in the first prefabricated hole, and the two ends of the split bolt are located in the two second prefabricated holes correspondingly and are in threaded connection with limiting nuts correspondingly; basalt fiber boards are prefabricated at the bottoms of the cross beams and abut against the pile caps. The stability of the wharf structure can be improved.

Provided in the present invention are an assembly-type pile-top connecting structure and a construction method. The assembly-type pile-top connecting structure comprises pile foundations, wherein a plurality of shear keys are welded to the outer side of the top of each pile foundation, pile-top connecting devices are provided on the pile foundations, the pile-top connecting devices on the plurality of adjacent pile foundations are fixedly connected, and precast beams for assembly are placed on the pile-top connecting devices; a steel sleeve is fixedly arranged at the bottom of a steel plate in each pile-top connecting device, a wedge-shaped support is fixedly arranged in the steel sleeve, the steel sleeve is located on the outer side of the top of a pile foundation, and the wedge-shaped support is supported on the inner side of the top of the pile foundation; and a water-stop rubber ring is provided between the inner side of the bottom of the steel sleeve and the pile foundation, and a grouting material fills the space between the steel sleeve and the pile foundation. Conventional pile caps are eliminated, and the pile foundations are directly connected to transverse and longitudinal precast beams and joints by means of the pile-top connecting devices, such that the green and industrialized construction of marine engineering structures is realized.

The invention discloses a full-prefabricated assembly type double-column high pier device and a construction method thereof.The device comprises a cover beam (13), a bearing platform (6), a pier column upper section (11), a pier column lower section (1) and a pier column middle section (10) with a tie beam, and socket holes (14) are formed in the bottom face of the cover beam (13) and the top face of the bearing platform (6); pier column socket sections (9) embedded in socket holes (14) are arranged on the upper portion of the upper pier column section (11) and the lower portion of the lower pier column section (1) respectively, gaps (3) between the pier column socket sections (9) and the socket holes (14) are filled with high-strength shrinkage-free cement grouting materials (4), and corrugated steel pipes (5) are adopted by the inner walls of the socket holes (14) of the cover beam (13) and the bearing platform (6) to serve as permanent templates. The component is low in transporting and hoisting difficulty, the mechanical property of a connecting joint is reliable, the construction precision requirement is low, and good economic benefits are achieved.

The invention discloses a dynamic temperature regulation and control method for a mass concrete cooling water pipe of an anti-collision pier bearing platform. The method comprises the steps of deployment of a monitoring module, preprocessing of multi-source monitoring data, deployment of an execution module, establishment of a neural network model, training of the neural network model, real-time continuous decision making and dynamic temperature regulation and control. A neural network model based on physical constraints ensures that the regulation logic conforms to the thermodynamic law; through historical multi-working-condition data training, the model can respond to the environment change and the hydration process in real time, the optimal regulation and control parameters are output, the limitation of a traditional empirical formula or a simplified model is solved, and dynamic optimization regulation and control are achieved.

According to the composite roadbed based on the rigid piles, the rigid piles are buried in the soft soil layers below the common soft soil roadbed and the immersed soft soil roadbed, and the pile caps are arranged on the sand cushion layers of the soft soil roadbed and are connected with the rigid piles, so that the roadbed and the foundation form a whole, and upper loads are effectively dispersed and transmitted to the deeper soil layers; the overall bearing capacity and stability of the foundation are improved, and the condition of foundation settlement caused by too high water content of the soft soil layer is effectively avoided; meanwhile, the permeable filler layer is arranged between the immersed soft soil roadbed and the soft soil layer, so that the overall strength and stability of the immersed soft soil roadbed can be further enhanced, and the immersed soft soil roadbed and a common soft soil roadbed are prevented from uneven settlement; and the seepage resistance of the soil layer can be effectively reduced by utilizing the good water permeability of the filler, so that water in the soaked soft soil roadbed can be discharged more smoothly, and the condition of sedimentation caused by untimely water discharge of the soaked soft soil roadbed can be avoided.

The invention discloses a highway foundation variable-stiffness pile arrangement method suitable for permafrost canal-shaped degradation. The method comprises the steps that spatial distribution of foundation stiffness is determined; designing the number of prefabricated pipe piles and pile arrangement; drilling and cleaning holes; the prefabricated pipe pile is pressed in and grouted for reinforcement; and pile cap pouring and reinforcement treatment. The corresponding number of long piles and dense piles are arranged in the severe permafrost degradation area for strong reinforcement, the short piles and sparse piles are arranged in the slow permafrost degradation area for weak reinforcement, the foundation rigidity is leveled by adjusting and controlling the strength, the space balance of the foundation bearing capacity is achieved, roadbed deformation caused by uneven settlement of the foundation is eliminated, and the foundation quality is improved. Wherein the long piles and the short piles extend into 2 m below the upper limit of frozen soil, and the foundation bearing capacity is improved; the dense piles can effectively disperse loads and reduce foundation settlement and displacement.

The invention relates to the technical field of civil construction, in particular to a zero-distance anti-displacement steel plate supporting method for an existing double-step bearing platform of a deep foundation pit. According to the technical scheme, the technical problem that under the extreme working conditions that a foundation pit with the depth of-8 m is zero in distance from the bearing platform and piling and bolt planting cannot be conducted, accurate displacement prevention protection is conducted on an existing double-step bearing platform is solved. In the construction process, firstly, layered excavation is conducted, and a supporting benchmark is arranged; hoisting an anti-displacement steel plate wall with preset grouting holes, and reinforcing a soil body at the bottom of the anti-displacement steel plate wall by injecting cement and the like; assembling a first-order reinforced occlusion hoop on the lower-order bearing platform; a three-stage multi-dimensional adjustable inclined support is installed, and graded pre-tightening force is applied; deep excavation is continued under dynamic monitoring, and the support is adjusted in time; and finally, orderly backfilling and dismantling are conducted. Through the combination of grouting reinforcement, hoop occlusion limiting and graded adjustable inclined struts, low-disturbance and high-precision displacement control over the existing bearing platform is achieved, the lower prefabricated pile is effectively protected, and construction safety and efficiency are remarkably improved.

The invention discloses an anti-settlement integral structure for an indoor equipment foundation, which is characterized in that the structure comprises a foundation plate, a pile foundation, a pile cap and a foundation beam, the foundation plate is configured to bear indoor equipment, and the range of the foundation plate covers the range of a whole equipment room; the lower part of the foundation plate is connected with the pile cap and the foundation beam; the foundation beams are arranged between the pile caps on the lower portion of the foundation plate and used for connecting the multiple pile caps and the foundation plate. The pile cap is arranged below the frame column, the upper part of the pile cap is connected with the foundation plate, and the lower part of the pile cap is arranged on the pile foundation; one end of the pile foundation supports the pile cap, and the other end of the pile foundation is fixed on the ground. Compared with the prior art, the foundation plate with the small thickness is adopted to replace a traditional thick raft plate, the engineering amount of a foundation and a pile foundation is remarkably reduced, and therefore the engineering cost is reduced. And the foundation beam is arranged below the thin foundation plate, so that the span of the plate is reduced, the thickness is reduced, and meanwhile, effective bearing can still be realized. By means of the structure, the load of the foundation plate is transmitted to the pile foundation through the foundation beam instead of being directly borne by indoor filling soil. Therefore, even if indoor filled soil settles, the foundation plate and equipment above the foundation plate cannot be influenced, and foundation settlement is effectively reduced.

The invention discloses a construction method for an ultra-large-area pile bearing terrace of a whole vehicle plant. Comprising the following steps of pile group construction modeling analysis, stress release measures, pipe pile construction, pile head treatment, pile core grouting construction, base layer treatment and cushion layer construction, PE damp-proof layer construction, pile cap construction, special structure junction construction, terrace steel bar binding, armored seam installation, concrete pouring and tamping, elevation and flatness control, wear-resistant carborundum ground construction and flatness rechecking. According to the method, pile groups are adopted to effectively support the terrace, the influence caused by differential settlement of the terrace in the later period is avoided, the concrete mixing proportion is optimized, the abrasion resistance and crack resistance of the terrace are enhanced, detail nodes are optimized for the positions prone to cracking and the joints of the terrace and special structures, and the construction efficiency is improved. And through the methods of alternate bin pouring, short-distance stress release, reasonable construction organization and the like, the anti-cracking requirement of the standard on the large-area terrace is met, and the construction period is greatly shortened.

The invention discloses a soft soil area transformer substation multi-load foundation structure which comprises pipe pile bearing platforms, prestressed pipe piles and integrally-arranged beam plate type rafts, and the multiple pipe pile bearing platforms are arranged at the positions, corresponding to an accident oil pool area, a road cable trench area, a power distribution building area and a main transformer area, below the beam plate type rafts. Two vertically-arranged prestressed pipe piles are connected to the lower portion of each pipe pile bearing platform corresponding to the accident oil pool area, two vertically-arranged prestressed pipe piles are connected to the lower portion of each pipe pile bearing platform corresponding to the road cable trench area, and 3-8 prestressed pipe piles are connected to the lower portion of each pipe pile bearing platform corresponding to the power distribution building area according to the load difference. And six pre-stressed pipe piles which are vertically arranged are connected below each pipe pile bearing platform corresponding to the main transformer area. Continuous load transmission and overall stress of the foundation structure can be achieved, the problem that differential settlement of all areas is too large is effectively solved, the structural durability is improved, the local stress concentration risk is reduced, and the bearing reliability is improved.

The invention discloses an inverted trapezoidal pile cap and connecting beam combined pile-supported embankment structure and a construction method thereof. The structure sequentially comprises a foundation treatment layer, a rigid pile layer, a pile cap layer, a connecting beam layer, a mattress layer, a reinforcement layer and an embankment filling layer from bottom to top. The rigid pile layer comprises a plurality of cast-in-place piles or precast piles vertically arranged in the foundation. The pile cap layer is arranged at the top of the rigid pile, the pile cap is of an inverted trapezoidal structure with a square section, and the top plane size is larger than the bottom to form a load diffusion slope. The adjacent pile caps are connected through connecting beams with circular sections to form a space overall stress system. Grouting pipelines are reserved in the pile cap and the rigid pile and used for later reinforcement. The load transfer area is enlarged through the inverted trapezoidal pile caps, the horizontal rigidity and the torsion resistance are improved through the circular connecting beams, and the overall stability, the anti-settling performance and the long-term service life of the embankment are remarkably improved by combining the grouting pipelines and the reinforcing ribs.

This invention discloses a lifting method for grouting reinforcement of pile foundations on thick island fill foundations, comprising the following steps: Step 1: Measure settlement data and arrange first grouting holes around the outer ring of the pile cap; arrange second grouting holes inside the pile cap; arrange third grouting holes between pile caps; Step 2: Simultaneously grout through the first and second grouting holes to form a first-class bearing layer; Step 3: Grout through the third grouting hole to form a second-class bearing layer; Step 4: Perform low-pressure slow grouting on the foundation soil at the bottom of the pile cap, stopping grouting when the lifting data of the pile cap reaches more than half of the initial settlement data; Step 5: Perform low-pressure slow grouting on the pile fill around the pile at the bottom of the pile cap until a pile-soil bond is formed; wherein, a lifting zone is formed between the first-class bearing layer and the pile-soil bond; Step 6: Simultaneously grout the lifting zone through the first and second grouting holes until it is lifted to a preset height, thus completing the pile foundation grouting reinforcement lifting.

The invention discloses a method for testing compressive static load of a single pile of a cast bearing platform and a cast bottom plate, which comprises the following steps of: 1) chiseling a circle of concrete, close to the bearing platform, of the bottom plate, and cutting off longitudinal reinforcing steel bars and transverse reinforcing steel bars anchored with the bearing platform in a reinforcing mesh of the bottom plate; (2) a static load test device is arranged, and a compression resistance static load test is carried out; (3) a plurality of outer ring grooves and inner ring grooves are dug in the side face of the circle of bottom plate and the side face of the bearing platform, and an annular water swelling strip is fixed to each ring groove; a plurality of grouting anchor sleeves with grouting holes are adopted to be connected with all longitudinal steel bars and transverse steel bars in the bottom plate steel bar mesh cut off in the first step in a one-to-one correspondence mode; (4) a circle of inner ring grouting annular pipe is pre-buried at the bottom of the side face of the bearing platform; a circle of outer ring grouting annular pipe is pre-buried at the bottom of the side face of the bottom plate; and (5) concrete, close to the bearing platform, of the bottom plate is poured again. According to the method, the workload is greatly reduced, and the structural strength and good waterproof performance can be ensured.