88 results about "Shallow foundation" patented technology

The invention provides a flood scouring damage simulation method for a shallow foundation bridge, which comprises the following steps: S1, riverbed scouring characteristics are analyzed, and data needing to be extracted comprise scouring depth, a pier peripheral flow field and a scouring pit form; s2, establishing a structure model; s3, adopting a point cloud reverse engineering technology and a fluid-solid coupling technology to transmit foundation soil contact and water flow load into the structure model; s4, structural damage analysis under the combined action of the flood and the loaded vehicle; and S5, obtaining a structural safety evaluation conclusion of the bridge under the combined action of flood scouring and heavy vehicle load through simulation and data analysis. The device has the advantages that the scouring effect of flood on the shallow foundation is accurately simulated, the combined action of foundation void and vehicle eccentric load is accurately simulated, multi-physical field coupling among water flow, soil, heavy vehicles and a bridge structure is achieved, simulation is convenient, accurate and rapid, and the cost benefit is high.

The present invention relates to the technical field of building foundation reinforcement deviation correction, and provides a building reinforcement lifting method based on numerical simulation, comprising: establishing an initial building model representing a building experiencing subsidence, and acquiring an initial subsidence displacement of the building; on the basis of the initial building model, adjusting shallow foundation parameters under the building foundation, simulating reinforcement of the shallow foundation, and forming a reinforced shallow foundation model; on the basis of the reinforced shallow foundation model, adjusting deep foundation parameters under the building foundation, simulating reinforcement of the deep foundation, and forming a reinforced deep foundation model; and, on the basis of the reinforced deep foundation model, dividing an intermediate lifting layer located between the deep foundation and the shallow foundation into a plurality of lifting areas and, on the basis of the subsidence displacement of each area, performing corresponding simulated lifting to implement simulated lifting of the building. The present method uses a numerical simulation approach to perform simulated optimisation on actual grouting deviation correction engineering cases, achieving both engineering economy and safety.

The invention relates to a deep and thick high-temperature permafrost region highway foundation bearing capacity enhancing method which comprises the following steps: detecting the bearing capacity of a permafrost foundation through static sounding to obtain the spatial distribution characteristics of the bearing capacity of an original-state foundation; the spatial distribution characteristics of the bearing capacity of the undisturbed foundation at least comprise a bearing capacity mean value, a bearing capacity range and a bearing capacity decline ratio; establishing a mapping model at least based on the spatial distribution characteristics of the original-state foundation bearing capacity and the shallow foundation enhancement mode; based on the mapping model, according to the spatial distribution characteristics, obtained through detection, of the original-state foundation bearing capacity, the shallow foundation strengthening mode is determined, and the shallow foundation strengthening mode comprises a structural strengthening measure, a material strengthening measure and a hydrological regulation and control strengthening measure and is used for improving the overall bearing performance of the foundation and restraining permafrost degradation; the structural reinforcing measure at least comprises the steps that a composite bearing structure system is constructed in a shallow foundation, and the mechanical property of the whole foundation is improved by enhancing the bearing capacity of a local area of the foundation.

The invention discloses an in-situ solidification construction method for a highway shallow foundation in a water-rich section of a permafrost region. The in-situ solidification construction method comprises the following steps: step 1, preparation at the early stage of construction; secondly, steel sheet pile enclosure water insulation is conducted; thirdly, in-situ soil solidification construction is conducted; fourthly, dynamic compaction encryption treatment is conducted; step 5, quality detection and molding acceptance inspection; and step 6, subsequent environmental protection and safety guarantee. Three dimensions of a steel sheet pile waterproof technology, a high-weather-resistance composite curing material in-situ curing technology and a dynamic compaction technology are integrated, and a set of systematized and standardized construction scheme is formed. According to the multi-dimensional combined method, the foundation treatment effect is improved, the comprehensiveness and pertinence of construction are enhanced, and a more effective solution is provided for road foundation treatment in the water-rich section of the permafrost region.

The invention provides a method for analyzing the composite bearing capacity of an ocean engineering shallow foundation, which comprises the following steps of: describing the soil property by combining a corresponding constitutive model through a finite element analysis method, establishing a shallow foundation-multilayer foundation soil interaction model, systematically exploring a shallow foundation damage mechanism under the action of each combined load through multiple groups of probe tests, and analyzing the composite bearing capacity of the ocean engineering shallow foundation. According to the method, the coupling effect between the load components is researched, normalized damage envelope surfaces in different load planes are obtained and fitted into algebraic expressions for checking the bearing capacity of the shallow foundation, and the bearing capacity calculation efficiency can be greatly improved. According to the method, for shallow foundations of different sizes and different load combinations, repeated modeling analysis is not needed, the corresponding ultimate bearing capacity can be directly obtained by writing the envelope line equation into an automatic calculation program and inputting design conditions, the design efficiency is remarkably improved, and the shallow foundations can be popularized and applied in offshore engineering projects.

The invention discloses a transformer iron core overturning system without hoisting, and relates to the technical field of transformer production equipment. The hinging module is mounted on the first supporting part of the base, and a main overturning module and an auxiliary overturning module are hinged to the two sides of the hinging module respectively; the main overturning module comprises a main platform, and the bottom of the main overturning module is connected with a plurality of main telescopic cylinders installed on the second supporting parts; the auxiliary overturning module comprises an auxiliary platform, and the auxiliary platform comprises a platform support; the main telescopic cylinder and the auxiliary telescopic cylinder can respectively push the main platform and the auxiliary platform to rotate towards each other at the maximum angle of not less than 90 degrees; the lamination table is used for laminating iron cores; and the transfer bracket is used for receiving the iron core overturned by the lamination table. Dependence on a travelling crane and a travelling crane worker is reduced, overturning is stable and reliable, the purchasing requirement of a large-tonnage travelling crane and shallow foundation design are omitted, the foundation depth is greatly reduced compared with a traditional hydraulic overturning table, and civil engineering construction cost and period are greatly saved.

The invention discloses a damage assessment method for a shallow-buried foundation bridge under a flood disaster. The method comprises the following steps: constructing a finite element model of the shallow-buried foundation bridge; introducing uncertainty of flood level height, foundation scouring pit length and scouring depth by applying a random Pushover method, obtaining bridge pier top yield displacement of the shallow foundation bridge under multiple groups of scouring working conditions, and calculating first two moments of logarithm of the flood-fighting capacity of the structure to obtain the flood-fighting capacity; performing flood-fighting demand analysis on the response of the shallow-buried foundation bridge in different flood washing environments based on a finite element reliability method; the flood-fighting capacity is compared with demand analysis, the failure probability of the shallow-buried foundation bridge under different working conditions is evaluated, fitting is conducted through the least square method, and a vulnerability curve of the shallow-buried foundation bridge is generated. According to the damage assessment method for the shallow-buried foundation bridge under the flood disaster, the influence of multiple factors such as the flow velocity and the scouring depth on the performance of the shallow-buried foundation bridge can be quantified, and the damage state of each stage of the shallow-buried foundation bridge is effectively assessed.

The invention discloses a foundation pit mixed supporting structure and a construction method thereof, relates to the technical field of foundation pit supporting, and aims to solve the technical problems that in the prior art, all supporting parts are poor in collaboration, the due supporting effect is difficult to give full play, and the foundation pit collapse risk is high. Comprising a single-layer fulcrum structure in the form of adding a pre-stressed anchor cable to a common Larsen pile arranged on the side adjacent to a building. On the side adjacent to the structure, the Larsen steel sheet piles and the pre-stressed anchor cables achieve the synergistic effect, large lateral soil pressure can be borne, a solid foundation is provided for supporting, the foundation pit is prevented from deforming towards the structure, the soil nailing wall reinforces the soil body above the bottom elevation of the shallow foundation, and the integrity and the anti-sliding capacity of the side slope soil body are enhanced. By means of the improved construction technology, it can be ensured that all parts fully play roles, the foundation pit collapse risk is effectively reduced, and the surrounding structure and construction safety is guaranteed.

The present invention discloses a tailings cementation filling construction method applicable to deep wells, and relates to the technical field of deep well filling. The tailings cementation filling construction method applicable to deep wells comprises the following steps: S1, excavating shallow pits around the deep well using a shallow foundation pit excavation method, the number of shallow pits being excavated being 6-8, the depth of the shallow pits being the deepest depth that can be excavated using the shallow foundation pit excavation method, the effective diameter of the shallow pits being equal to the effective radius of the deep well, and the shallow pits being arranged symmetrically relative to the deep well during construction. The tailings cementation filling construction method applicable to deep wells, by digging additional shallow pits and filling them with the sand and soil obtained when digging the shallow pits, the sand and soil filling layer divides the tailings cementation filling layer into two layers, thereby reducing the thickness of the single-layer tailings cementation filling layer, while increasing the exposed area of ​​the upper tailings cementation filling layer, and increasing the stability of the filling material. At the same time, the equipment used for digging and mixing is different and can be carried out simultaneously, and digging additional shallow pits does not affect construction efficiency.

The invention relates to the field of building construction, and discloses a deep and shallow foundation pit group construction deformation prediction control method, which comprises the following steps: acquiring engineering geological parameters of a construction site and foundation pit parameters of a plurality of foundation pits to be constructed; determining a plurality of calculation simulation working conditions; establishing a three-dimensional numerical model by adopting finite element software; simulating the states of the retaining structures of the first foundation pit, the second foundation pit and the third foundation pit in the construction process under different calculation simulation working conditions in the three-dimensional numerical model; deformation data of the adjacent foundation pit limited width soil strip enclosure structure and soil pressure data of the two sides of the adjacent foundation pit limited width soil strip are tested and fed back, and the construction requirement is adjusted according to the data fed back through detection; the three-dimensional numerical model is used for simulating the deformation condition of each enclosure structure of the deep and shallow foundation pit group under different construction sequences, different foundation pit distances and different loads among foundation pits, so that the actual construction requirements are adjusted, and the deformation trend of the enclosure structures in the actual construction process is controlled.

The application discloses a shallow foundation reliability analysis method and device. The method comprises the following steps: selecting a deterministic bearing capacity envelope surface equation of a shallow foundation according to requirements; obtaining a probability single-axis bearing capacity sample set; converting the deterministic bearing capacity envelope surface by using the probability single-axis bearing capacity sample to generate a large number of probability bearing capacity envelope surface samples; setting a load combination sample according to requirements, comparing the load combination sample with the bearing capacity envelope surface sample, and carrying out reliability analysis by combining a performance function and a Monte Carlo simulation. The core of the application is to solve the probability single-axis bearing capacity, combine the deterministic bearing capacity envelope surface equation, construct the probability bearing capacity envelope surface, and carry out the shallow foundation reliability analysis by using the Monte Carlo simulation. The method avoids numerical analysis for different load combinations respectively, greatly improves the calculation efficiency, and is simple in principle and convenient to use, thereby providing an efficient and practical tool for the shallow foundation reliability analysis under complex geological and load conditions.

The invention discloses an anti-cheating weighing apparatus and an installation method thereof, and solves the technical problem of material metering cheating of a ground scale and a deep pit ground scale. The anti-cheating weighing apparatus comprises a supporting seat, a sensor pre-embedded structure, a measuring element sensor, a weighing body and a bag type protection structure. The sensor pre-embedded structure is installed on the supporting seat. The sensor pre-embedded structure is installed on the supporting seat. The scale body is installed above the measuring element sensor, and the bag type protection structure is arranged around the scale body. The measuring element sensor of the anti-cheating weighing apparatus is located in the shallow foundation pit, so that illegal personnel are not easy to directly contact with the measuring element sensor, and the measuring element sensor cannot be cheated or cannot be additionally provided with wireless remote control equipment. Besides, by designing a bag type protection structure, on one hand, a physical isolation layer can be formed to prevent a measuring element sensor from being damaged or a cheating device from being additionally arranged, and on the other hand, scale body jamming caused by falling of foreign matters can be avoided.

The invention discloses an automatic dewatering and drainage device for a large-plane shallow foundation pit containing a weak permeable interlayer, which comprises drainage ditches including an annular drainage ditch and a linear drainage ditch, and a plash arranged at the intersection of the annular drainage ditch and the linear drainage ditch, the water seepage blind ditch is composed of a steel wire mesh, a steel reinforcement framework and gravel; the reinforcement cage is placed in the plash, the submersible pump is arranged at the bottom in the reinforcement cage, and the float switch water level controller is connected with the submersible pump and controls the submersible pump to be started and stopped so that water in the plash can be drained out of the plash. The annular drainage ditch and the linear drainage ditch are combined with the gridding layout of the plash, and then the submersible pump and the float switch water level controller are combined. Seepage water can be rapidly collected and drained, the drainage efficiency is improved by 40% or above, and the method is particularly suitable for the weak permeable interlayer geological condition of a large-plane shallow foundation pit.

The invention discloses a shallow foundation reliability analysis method and device. The method comprises the steps that a deterministic bearing capacity envelope surface equation of the shallow foundation is selected according to requirements; obtaining a probability uniaxial bearing capacity sample set; converting the deterministic bearing capacity envelope surface by utilizing the probability uniaxial bearing capacity sample to generate a large number of probability bearing capacity envelope surface samples; setting a load combination sample according to requirements, comparing the load combination sample with a bearing capacity envelope surface sample, and carrying out reliability analysis in combination with a performance function and Monte Carlo simulation. The core of the method is that the probability bearing capacity envelope surface is constructed by solving the probability uniaxial bearing capacity and combining a deterministic bearing capacity envelope surface equation, and the reliability analysis of the shallow foundation is carried out by adopting Monte Carlo simulation. According to the method, the situation that numerical analysis is conducted on different load combinations is avoided, the calculation efficiency is greatly improved, the principle is simple, use is convenient, and an efficient and practical tool is provided for shallow foundation reliability analysis under the complex geology and load conditions.

The present invention relates to the field of foundation pit protection, and discloses a green and environment-friendly safety protection device for engineering foundation pits, including a protection device body installed on the foundation pit, which is arranged in an array on the foundation pit. The lower part of the protection device body is obliquely inserted into the inner surface of the foundation pit, and a vertical protection plate with an "h" - shaped structure is arranged on the outer side of the upper part of the protection device body. Heavy objects are filled and compacted at the lower part of the vertical protection plate. Driven by a cylinder, the position of the inclined insertion plate can be flexibly adjusted according to the actual size and shape of the foundation pit. This adjustable design enables the protection device to adapt to foundation pits of different sizes and shapes without large-scale modification of the device. For example, in the case of a relatively narrow or shallow foundation pit, the telescopic degree of the cylinder can be adjusted to make the inclined insertion plate fit the inner surface of the foundation pit, so as to achieve the protection effect.

The invention discloses a method and device for calculating the ultimate bearing capacity of a shallow foundation of a deep replacement soft soil layer. The method comprises the following steps: firstly, constructing a limit failure surface model controlled by a single variable angle alpha according to a foundation, the size of replacement soil and soil layer parameters; then, force and moment balance analysis is conducted on the basis of the limit equilibrium principle, the foundation limit bearing capacity is decomposed into the sum of three subitem bearing capacities of ground overload, in-soil cohesive force and soil dead weight, and the function relation between each subitem bearing capacity and the variable angle alpha is deduced; and finally, establishing a function of the total ultimate bearing capacity relative to the variable angle alpha, and calculating the minimum value through derivation or iteration so as to determine the ultimate bearing capacity of the foundation. According to the method, the complex failure surface model which is more practical is constructed, rigorous mechanical derivation is carried out, the limitation that an existing method is only suitable for the homogeneous foundation or shallow layer replacement condition is solved, and a reliable theoretical basis is provided for foundation bearing capacity calculation of a deep replacement soft soil layer.

The present application relates to a kind of simple calculation method of shallow foundation and clay seabed interface failure time under extreme storm surge action.The technical scheme is: measuring the roughness R of shallow foundation a , making structure;Collecting seabed clay at shallow foundation, carrying out dynamic simple shear test, test structure and the initial undrained shear strength S of clay interface u ;Select and set 0.4S u , 0.6S u , 0.8S u And 1S u As the typical amplitude of extreme storm surge load;Measured structure and the corresponding period number N of clay interface failure;Fitting extreme storm surge load amplitude and period number N logarithmic curve;According to wave force calculation formula, load amplitude is calculated;The amplitude is substituted into logarithmic curve and the corresponding period number N of interface failure and failure time are obtained.The present application can calculate the failure time of shallow foundation and seabed interface under extreme storm surge, provide the time length of shallow foundation against storm surge, determine the stability of shallow foundation, provide feedback for whether the shallow foundation of engineering site needs to be reinforced to resist extreme storm surge.

The invention relates to the technical field of foundation reinforcement, and discloses a soil solidification device for unfavorable geological condition reinforcement under a shallow foundation, which comprises an admixture mixing device module used for uniformly mixing a solidified additive and water according to a certain proportion; the stirring equipment module is used for uniformly stirring the mixed additive solution and mucky soil collected on site; the conveying pipeline module is used for conveying the stirred solidified soil to a designated position of the injection system from stirring equipment; the injection system module is used for uniformly injecting solidified soil to the surface of a foundation to be treated; and the monitoring instrument module is used for monitoring the quality of the solidified soil and the improvement effect of the foundation in real time. By controlling the mixing ratio and fully stirring, the quality of the solidified soil is effectively improved in each link. The high-quality solidified soil is applied to foundation reinforcement, unfavorable geology can be better improved, the bearing capacity and stability of a foundation are enhanced, the problems of foundation settlement and the like are effectively reduced, and the reinforcement effect of a building is guaranteed.

The utility model discloses a kind of first tunnel after well method foundation pit supporting structures, including underground continuous wall, the underground continuous wall is set in first tunnel after well method tunnel area upper foundation pit and tunnel area foundation pit junction, concrete crown beam is provided on the underground continuous wall, a mortar anchor rod is provided inside the concrete crown beam. The present application is mainly applied to the supporting structure between deep and shallow foundation pits, which can ensure the safety of foundation pit excavation, improve construction efficiency and reduce construction cost.

This invention discloses a method for calculating the bearing capacity of shallow foundations by integrating machine learning and nonlocal algorithms, belonging to geotechnical engineering. 1. The type of foundation soil is determined through indoor triaxial tests; strain-hardening foundation soils are analyzed; 2. Strain-softening foundation soils are analyzed; 3. A finite element model is established for refined simulation, followed by 7. 3. A constitutive model combined with a nonlocal algorithm is used for refined simulation, then proceeds to 4. 4. The influence range (DL) of the shallow foundation analysis is calibrated. f DL is determined by the softening rate control parameter β. f If suitable, proceed to step 7; otherwise, proceed to step 6. Step 6 involves building and training a machine learning agent model to ultimately obtain a suitable deep learning (DL) algorithm. f Shallow foundation analysis was performed with β1 and 7 to obtain the predicted value of the foundation bearing capacity. The present invention uses the above method to achieve efficient inversion of nonlocal parameters, thereby obtaining a reasonable predicted value of the shallow foundation bearing capacity.

The invention discloses a method for preventing and treating ground collapse induced by the pot cover effect of a buried heat pipe, and relates to the technical field of geotechnical engineering.The method comprises the steps that a heat radiation area of the heat pipe is analyzed, the laying position and the arc length of a water-proof and vapor-proof structural layer are determined, and the structural shape is a piece of symmetrical arc-shaped water-proof and vapor-proof geotechnical cloth. A temperature difference is formed between a high-temperature area caused by the buried geothermal pipe and a low-temperature area of a road surface, water vapor in unsaturated soil of a foundation is driven to migrate to a cold area under the ground, water returns to the high-temperature area under the action of gravity, the water content of a soil body is increased in the process, and the process is called the pot cover effect of the buried geothermal pipe. Long-time water vapor circulation action and induction of ground collapse under the action of external load are common engineering disasters. According to the method for preventing and treating the ground collapse induced by the pot cover effect of the buried heat pipe, vapor-state water on the lower layer can be prevented from migrating to the shallow foundation, and the disaster of the ground collapse induced by increase of the water content of the roadbed can be avoided.

The application provides a stability evaluation method based on an envelope surface of a shallow foundation bearing capacity under wave load. The technical scheme is: collecting soil samples on the engineering site and carrying out test calibration of soil parameters; establishing a three-dimensional numerical model based on a modified Cambridge model and calculating the initial bearing capacity of the shallow foundation; selecting and applying representative amplitudes of wave load to the shallow foundation to obtain the horizontal-moment bearing capacity envelope surface under different amplitudes of wave load; calculating the actual horizontal and moment loads borne by the shallow foundation according to the on-site wave load and determining whether the actual horizontal and moment loads are below all the horizontal-moment bearing capacity envelope surfaces to determine the stability of the shallow foundation. The application can truly simulate the working condition of the shallow foundation bearing the combined action of horizontal and moment cyclic loads in the marine environment, calculate the bearing capacity envelope surface of the shallow foundation under different amplitudes of wave load, determine whether the shallow foundation has a safety hazard, and provide a reference for whether reinforcement treatment measures need to be taken for the in-situ shallow foundation.

This invention relates to the field of road construction technology and discloses a reverse-construction cut-and-cover method for converting a highway into a bridge. The method includes the following steps: construction preparation and half-width closure, integrated pile-column construction, cap beam and superstructure construction, traffic diversion, reverse-construction cut-and-cover of the soil under the bridge, pier appearance treatment, and repeated construction. This invention directly constructs an integrated pile-column structure on the existing road surface, completely eliminating the need for deep foundation pit excavation (over 9 meters). It transforms high-risk deep foundation pit projects into low-risk shallow foundation pit projects, effectively avoiding safety accidents such as foundation pit collapse and roadbed slippage. Simultaneously, it eliminates the interference of deep foundation pit construction on adjacent highways, ensuring the safety of both construction personnel and passing vehicles.

The lower chassis assembly of the double-chassis elevator comprises side beams with grooves in the inner sides and cross beams with the ends extending into the grooves to be fixedly connected, the cross beams and the side beams are combined to form a four-side frame structure on the same layer, and the end faces of the cross beams are attached to and fixedly connected with the inner side faces of the side beams. The ends of the cross beams extend into the side beams to be fixedly connected, the cross beams and the side beams are located on the same layer, the lower chassis is only as high as the side beams, the cross beams do not occupy extra height space, and therefore the lower chassis assembly occupies little height space. The cross beams are inserted into the grooves of the side beams to be directly welded and fixed, the ends of the cross beams do not need to be sealed and fixed through sealing plates, and the manufacturing cost is lower. The elevator with the lower chassis occupying small height space has lower requirements on the depth of the existing foundation pit, and the shallow foundation pit does not need to be excavated and deepened again, so that the time, manpower and money cost is saved.

The invention provides an anti-seismic testing method and system for a railway gravity type pier shallow foundation, and relates to the technical field of anti-seismic testing. The method comprises the steps that a plurality of test models of the railway gravity type pier shallow foundation are manufactured, and a quasi-static test is carried out; acquiring side substrate pressure of multiple times of displacement loading of the multiple test models; according to the side base pressure, the base lift-off amount is determined; acquiring the horizontal displacement and the horizontal load of the pier top subjected to multiple times of displacement loading of the plurality of test models; acquiring a force-displacement hysteresis curve of the plurality of test models; determining an equivalent stiffness attenuation gradient; when the quasi-static test is finished, crack parameters of the multiple test models are obtained; determining a crack energy dissipation ratio; and the anti-seismic performance of the railway gravity type pier shallow foundation is determined. According to the device and the method, the anti-seismic performance of the railway gravity type pier shallow foundation can be tested according to the foundation lift-off amount, the equivalent stiffness attenuation gradient and the crack energy dissipation proportion, and the accuracy and comprehensiveness of the anti-seismic test are improved.

The utility model relates to the technical field of buildings, and discloses a shallow foundation building deviation rectifying and reinforcing structure which comprises a reinforcing base and further comprises supporting plates fixed to the two sides of the top of the reinforcing base, the rear sides of the opposite sides of the two supporting plates are rotationally connected with a two-way lead screw, and one end of the two-way lead screw is fixedly connected with a first rotating disc. And moving frames are arranged on the two sides of the top of the reinforcing seat. A two-way screw rod can be rotated by rotating a first rotating disc, a movable frame drives two clamping rings to relatively move in cooperation with a threaded sleeve, if a supporting column needing deviation rectification is round, an L-shaped plate can be taken out from the interior of a clamping groove, then the two clamping rings abut against the surface of the supporting column, and first-layer reinforcement and correction are conducted through screws on the two sides; and then a second rotating disc is rotated to enable a screw rod to rotate in a moving frame, and a connecting ring is matched to move to abut against the surface of the supporting column for reinforcement and correction, so that the size of the supporting column can be corrected according to needs for adjustment and reinforcement.

The utility model provides a lifting platform device for a stage, and relates to the field of stage mechanical equipment. The device comprises a mounting base and a table top, guide mechanisms and a flexible column jacking driving mechanism are arranged between the mounting base and the table top, the flexible column jacking driving mechanism is arranged between a pair of symmetrically arranged guide mechanisms, and the flexible column jacking driving mechanism drives the table top to do lifting motion; the flexible column jacking driving mechanism comprises a short connection column, a jacking chain set, a pin gear box, a double-shaft gear motor and a storage box, a protection mechanism is installed on the outer side of the table top, and a stroke limiting switch and a fire breaker are fixedly installed on the installation base. A flexible column jacking and lifting mode is adopted, the lifting platform has the advantages of being shallow in foundation pit, high in speed, large in stroke, heavy in load and high in transmission precision and structural stability, the highest working elevation of the platform face extends out of the stage by 2 m, and the platform face can serve as a front extension part of the stage. A guide mechanism is adopted for guiding, the stability of the lifting process is improved, and the lifting safety is improved through a stroke limiting switch.

The utility model relates to the field of stereo garages, in particular to opposite-layer shallow foundation pit lifting equipment which is characterized in that a frame body is built in a foundation pit, a driving base is fixedly built at the bottom of the frame body, and an upper-layer vehicle carrying plate and a lower-layer vehicle carrying plate are movably arranged above the driving base; the upper-layer vehicle carrying plate and the lower-layer vehicle carrying plate are integrally arranged and are connected through supporting columns; and a plurality of limiting cavities are formed in the two sides of the upper-layer vehicle carrying plate and the two sides of the lower-layer vehicle carrying plate correspondingly, fixing bases are arranged on the portions, located on the two sides of the frame body, above the foundation pit correspondingly, limiting pieces are movably arranged in the fixing bases correspondingly, and the limiting pieces are matched with the limiting cavities correspondingly. Parking and taking of vehicles can be achieved through the upper-layer vehicle carrying plate and the lower-layer vehicle carrying plate, fixing and supporting of the upper-layer vehicle carrying plate and the lower-layer vehicle carrying plate can be achieved through clamping between the limiting pieces and the limiting cavities, and therefore the situation that in the using process, the vehicle carrying device rapidly falls off due to faults is prevented; therefore, property safety and life safety of the user are guaranteed.

The invention belongs to the field of foundation pit excavation, and particularly discloses a portable shallow foundation pit excavation device which comprises a conveyor belt type flat excavation mechanism, a self-adaptive opening and closing soil unloading mechanism, an intrusion control mechanism and a moving advancing mechanism. The conveyor belt type flat digging mechanism is arranged on the invasion control mechanism, the invasion control mechanism is arranged on the moving advancing mechanism, and the self-adaptive opening and closing soil unloading mechanism is arranged on the conveyor belt type flat digging mechanism. Through the elastic excavation assembly and the unfolding and unloading assembly which are arranged along the conveying belt body in an array mode, a small amount of soil can be continuously excavated from the bottom, unloading is automatically completed at the top, adhesion and residue of the soil can be avoided in an automatic opening and local vibration mode, and under the condition that no electric control system is relied on, the conveying belt is convenient to use. The technical effects of automatic earth cutting and unloading are achieved only through an ingenious mechanical structure.