Method of identification and elimination of defects produced in ground piles

FIELD: construction.

SUBSTANCE: method of identification and elimination of defects produced in ground piles includes well formation, installation of reinforcement cage in it, laying communication lines, supplying solidifying composition into the well, for example concrete mixture. Before installing the reinforcing cage, the electrodes are fixed on it, and they are connected to the communication lines. After supplying solidifying composition, its electrical conductivity is monitored, and if there are defects is the wellbore, partial pumping of solidifying composition is made, the defect is eliminated, and then solidifying composition is again supplied into the well.

EFFECT: increased reliability of ground piles by providing the ability to control the wellbore continuity and eliminate defects in the production process.

1 tbl, 4 dwg

 



 

Same patents:

FIELD: construction.

SUBSTANCE: method includes foundation excavation with uncovering of grillage foot, alternating execution of two slots from side of opposite corners of the cross section of the pile shaft with installation of flat jacks in them, cutting of fittings in two other corners of the cross-section of the pile shaft, separation of pile from grillage by stretching the remaining concrete section of the pile shaft by means of jacks, static testing of pile by indentation with measurement of its movements. Method permits to determine the load-bearing capacity without interrupting work of the pile being tested and without reducing the load on it and not allowing movements, usually occurring when the load is removed. Stress state of soil mass holding the pile, that was formed during operation of foundation, remains unchanged.

EFFECT: increasing the reliability of determining the load-bearing capacity.

5 dwg

FIELD: construction.

SUBSTANCE: method for driving a pile into soil consists in determination of pile parameters and hammer parameters, performance of dynamic tests by driving of the pile into soil by means of a hammer with determination of pile faults, as per which and as per pile parameters and hammer parameters, the carrying capacity of the pile is determined as per the specified dependence. Before a pyramidal pile is driven into soil, its weight and cross-sectional area of its upper and lower bases is determined, as per which such a prismatic pile is chosen, the weight of which is equal to the weight of the pyramidal pile. The cross-sectional area of the prismatic pile is equal to half sum of cross-sectional areas of the upper and lower bases of the pyramidal pile. Dynamic tests of this prismatic pile are performed. Load-carrying capacity of the pyramidal pile is determined as load-carrying capacity of this prismatic pile as per the specified ratio of parameters, considering faults obtained during tests of the prismatic pile.

EFFECT: improving operating reliability of buildings and structures at simultaneous increase of a possibility of using pyramidal piles on collapsible soils and in mass construction; improving soil compaction.

2 dwg

FIELD: construction.

SUBSTANCE: in this method for testing the foundation soil of piles with grillage, which includes application of force to the pile with grillage in the form of rigid square plate in plan, registration of the applied force and draft of pile with grillage and calculation of soil resistivity, plate of grillage is made horizontally and symmetrically located with respect to the pile, the following is placed under the grillage: elastic plate, having dimensions of plate of grillage in plan, thickness 0.05-0.1 of size of grillage plate sides, elastic module of 30-50 MPa and coordinate rectangular grid on lateral sides, grillage is moved until the complete contact of elastic plate with the surface of the foundation soil and fixed rigidly on the head of pile, in this case registration of the applied force and draft of pile with grillage is performed synchronously with simultaneous video recording of lateral sides of the elastic plate, and resistance of foundation soil to grillage and pile is calculated by formulas Pr=E·Δε·(Sr-Ss) b Ps=P-Pr, where Pr - resistance force of the foundation soil to the loaded grillage; Ps - resistance force of the foundation soil to the loaded pile; P - force applied to the pile with grillage; E - module of elasticity of the elastic plate; Δε - relative compression of elastic plate under the action of loaded grillage and resistance of foundation soil to the loaded grillage; Sr - surface area of the elastic plate in plan; Ss - cross sectional area of the pile.

EFFECT: simplification and reduction in price of determination of the load distribution on the foundation between the piles and grillage in concrete conditions of construction, definition of distribution of reactive normal stresses of subsurface base along the foot of grillage and increase of reliability of the results during one trial.

2 dwg

FIELD: construction.

SUBSTANCE: test method of a soil foundation with a pile with a grill involves application of a vertical force to a pile with a grill in the form of a square plate in a plan view, measurement of the applied force and settlement of the pile and calculation of soil resistance. A grill plate is horizontal and symmetrical relative to the pile and it has dimensions of sides, which are by 6 times larger than diameter of the pile, with thickness that is by 40 times less than the dimension of plate sides and from material with elasticity modulus of less than 210000 MPa, brought to the surface of the soil foundation till complete contact and rigidly fixed on the pile head, with that, at the same time, vertical movements of four angular points of the grill plate are measured and resistance of the soil foundation to the grill and the pile is calculated as per the specified relationships.

EFFECT: identity of tests of a soil foundation; improvement of reliable results at one test; simplification and cheapening of a test technology of the soil foundation with a pile with a grill.

2 dwg

FIELD: construction.

SUBSTANCE: continuously rising impressing load at a model pile is applied with permanent speed, and its value is accepted depending on diameter of the model pile, moisture, limits of plasticity and coefficient of soil porosity under a lower end of an experimental pile, based on the formula. Registration of the impressing load and settling of the model pile is carried out continuously with error of 100-200 N for the impressing load and 0.005-0.010 mm for pile setting. According to the data of registration of the impressing load and setting of the model pile, a curve is built for dependence of model pile setting speed on the impressing load, which is broken into three sections - 1st section with the permanent linear speed of model pile setting, 2nd section with non-linearly increasing speed of model pile setting that is 5-10 times higher than on the 1st section, and the 3rd section with the speed of model pipe setting that is 5-10 times higher than on the 2nd section, and the bearing capacity of the natural pile in the structure foundation is calculated using the data of the curve of dependence of model pile setting speed on the impressing load according to the formula.

EFFECT: higher validity and accuracy of determination of bearing capacity of a natural pile in a structure foundation and reduced labour costs.

1 tbl, 2 dwg

FIELD: construction.

SUBSTANCE: method to determine bearing capacity of a driven pile by application of a load to a pile and measurement of parameters of its submersion into soil. A reference base of wavelet images is created with vibrorecords of pile acceleration in three mutually perpendicular directions, one of which matches longitudinal axes of piles, in process of their driving into soil, at the specified frequency and energy of impact, characterising bearing capacity of piles for different soils and structural parameters of piles. Afterwards at least in 5 days bearing capacity is identified for each pile by means of its loading with a static vertical load. In process of driving a working pile with the specified frequency and energy, a wavelet image of acceleration vibrorecords is produced, which is compared to wavelet images by a correlation method. Based on the extent of correlation, the nearest reference pile is identified, and using its characteristic, the bearing capacity of the working pile is identified.

EFFECT: higher accuracy to identify bearing capacity and to reduce labour intensiveness and duration.

2 cl, 1 ex, 3 dwg

FIELD: construction.

SUBSTANCE: using new elements - disconnection of hollow sections from a central anchor rod, provision of each hollow section, apart from the upper one, with a concentrically installed hollow stem with a support plate fixed on top of it and pulled coaxially via cavities of above sections and stems, and installation of force-measuring sensors in tiers above the pile head, and also installation of elastic pads into grooves in ends of hollow sections, - results in appearance of new properties in the proposed technical solution, namely, higher reliability, accuracy and duration of measurements of tangential heaving forces acting at driven piles in process of soil freezing, also by simultaneous measurement (with the help of the same force-measuring sensors) of friction forces of non-frozen soil, acting at hollow sections below the freezing limit and accounted in corrections to tangential heaving forces. Arrangement of force-measuring sensors in tiers above a pile head, making it possible to use removable plant-manufactured force-measuring sensors with high class of accuracy and to regularly calibrate them upon completion of each season of measurements, makes it possible to monitor reliability and accuracy of completed measurements.

EFFECT: possibility to carry out long-term measurements of tangential forces of frost heaving and friction forces of non-frozen soil increases reliability and accuracy of produced results due to taking into account a long row of measurement data in statistical processing.

2 cl, 5 dwg

FIELD: construction.

SUBSTANCE: method to apply load to a pile, where an upper part is placed below the first pile section, at the same time the upper part is fixed to the first pile section. A bottom part is placed near the upper part, at the same time an area of separation is developed so that introduction of fluid medium under pressure into the separation area provides for a force striving to move the upper part and the bottom part from each other, and causes upward movement of the upper part in the first pile section. At least a part of a cross section in the upper part and at least a part of a cross section of the bottom part is open to ensure passage of materials on top from the upper part to the bottom from the bottom part. The upper part and the bottom part are placed prior to pile casting, at the same time materials for pile casting go through the open part of the cross section of the upper part and the open part of the cross section of the bottom part. If the upper part and the bottom part are separated, the upper part and the bottom part preserve their relative side position during separation, and the fluid medium is introduced into the separation area to apply the load to the pile.

EFFECT: reduced material intensity and labour intensiveness when testing higher bearing capacity of a pile.

28 cl, 7 dwg

FIELD: construction.

SUBSTANCE: in pit of appropriate depth, fragment of foundation and elements of seismic insulation made of loose materials are arranged, comprising seismic-insulation cushion under foundation and filling of pit pockets. Limit values of foundation vibration speed amplitudes, specified in process of design and permissible by conditions of its strength preservation, are determined. Explosion parametres are designed to obtain average amplitudes of foundation vibration speeds at the level equal to the limit values, for this purpose the expression VL=Vxyz=11.776X is used, with R2=0.815, where VL is vector speed of vibrations of average amplitudes of components (x,y,z) (Vxyz) of speeds transmitted by foundation soil through a layer of loose material of foundation, - reduced mass of charge, kg, R2 - coefficient of pairwise correlation, r - distance from explosion epicentre to the area of vibrations registration, m, h - depth of charge centre in well, m, QΣst - mass of charge in stage of explosion, kg, Knpc - coefficient that takes into account geological and relief conditions, varies from 1.0 to 3.0. On completion of explosive works, level of seismic action suppression is assessed, and if value of this characteristic is less than 2.7 points, thickness of cushion is increased, and/or composition of its material is chosen. Trials are repeated until amplitudes of foundation vibration speeds comply with conditions of its strength preservation.

EFFECT: improved reliability of building, structure seismic protection with reduction of capital and operational costs.

3 dwg

FIELD: construction.

SUBSTANCE: soil field tests are carried out with punch 6, test results are evaluated, particular value of limit soil resistance under pile foot is identified, at the same time casing pipe 3 is displaced, this displacement is fixed, particular resistance of soil is calculated on side surface of pile, and using superposition principle, bearing capacity of drilled pile is identified as sum of bearing capacity under pile foot and side surface. Method makes it possible, compared to prototype, to increase accuracy of drilled pile bearing capacity assessment up to 10%, to reduce number of piles in foundation grill by 7% as a result of high value of pile bearing capacity and to reduce number of tests by 6% due to high accuracy (validity) of assessment.

EFFECT: increased accuracy of drilled pile bearing capacity assessment.

1 cl, 3 dwg

FIELD: test equipment.

SUBSTANCE: the inverter device has a datum mark device with deflectometer, jack beam and hydraulic jacks. For testing of the tubular piles of the bridge seats by static press-in and separating loads the heads of the tubular piles are cut off approximately by one level. Pile caps are installed under the doubled hydraulic jacks on the two middle tubular piles that are symmetrical relative to the vertical axis of symmetry. The jack beam is installed on the doubled hydraulic jacks providing equal reactions on the pressed-in tubular piles and the separated extreme tubular piles.

EFFECT: enhanced rate of construction due to reduced time of mounting of the test equipment.

1 dwg

FIELD: building and construction.

SUBSTANCE: to increase precision of determining pile condition, mechanical excitation of pile is realized by hydrodynamic strike with spark break-through of inter-electrode emitter portion, mounted on pile head. Resilient oscillation receivers are mounted on end and side surfaces of pile. Receiver on side surface is mounted slanted relatively to pile axis. When separating echo-signal, reflected from pile bottom, spectral analysis is used and digital filtering of signal in certain frequencies range. To estimate condition of pile its planned length is compared to real length, determined from measurements data, and quality of pile material is determined from results of comparison of measured and planned speeds of resilient waves. Device for determining condition of pile has block for mechanical excitation of pile made in form of tank filled with electric-conductive liquid, with coaxial electrodes, connected using coaxial cable to high-voltage energy accumulator. Measuring device is provided with two resilient waves receivers.

EFFECT: higher precision, simplified construction, lower costs, broader functional capabilities, higher efficiency.

2 cl, 4 dwg

FIELD: building, particularly to control building structure member deformation.

SUBSTANCE: method involves embedding optical light guides in structure members; connecting light guide ends with each other to form at least one serpentine arrangement; linking light source and light receiver correspondingly to the first and the second ends of the serpentine arrangement; measuring optical power of serpentine arrangement and determining the first reference value from above measurement; measuring optical power of each light guide and determining the second reference value from above measurements; performing the third optical power measurement and comparing thereof with the first reference value; periodically performing the third measurement to find out structure member destruction. If the first reference value exceeds value determined during the third measurement one can judge that the structure member destruction has occurred. Then the forth optical power measurement of each light guide is executed and destructive light guides are discovered in light guide cross points.

EFFECT: increased accuracy, reliability and longevity of structure member destruction measurements.

2 cl, 5 dwg

FIELD: construction industry.

SUBSTANCE: bored pile bearing capacity determining method involves pre-construction of bored pile by means of rotational sinking into the soil of inventory casing pipe with the head that will be left in the soil; then, filling of inventory casing pipe with reinforcing bracing and concrete, and when the latter reaches design strength, static pressing load is applied to the pile, and its movement is measured. Before inventory casing pipe is filled with concrete, therein installed is a shell. Between shell bottom and head there arranged is a force sensor connected with recording equipment that is located on the soil surface. Force sensor is isolated from environment along the shell perimeter by means of a ring made from flexible material, which is also installed between head and shell bottom. Shell and force sensor are introduced in inventory casing pipe together with reinforcing bracing. Pile is tested by means of cyclic loadings after design strength is reached; besides force sensor readings are taken, for extracting some part of external load from force readings, which defines bearing capacity of bored pile, and for extracting variable and unstable part in the form of friction forces.

EFFECT: improving the accuracy of determining the bored pile bearing capacity.

2 cl, 7 dwg

FIELD: construction.

SUBSTANCE: method for monitoring of building under action of disturbances from displacement of its foundation includes reception, processing and assessment of controlled parametres from sensors installed onto building, which characterise current condition of the building, and prediction of further possible operation by detection of time resource available until critical value of controlled parametres is achieved. At first layout of sensors location is defined by detection of stressed-deformed condition of all elements in building structure on mathematical model of the building by method of finite elements, when building model is affected with disturbance from displacement of each foundation pile by value of 1 cm and more serially, alternately and in combination, with increase of displacement with pitch of 0.1-0.5 cm, imitating displacements of foundation piles and detection of points with maximum equivalent stress in elements of structure with minimum displacements of piles. Further on foundation grill in areas of location of building supports onto foundation piles or close to them, which produced maximum equivalent stresses in structure elements on model in process of their displacements, sensors of vertical displacement are installed, for instance of hydrostatic leveling. Signals received from sensors in operational mode are statistically processed in serial equal intervals Δt of time that make 15-60 min. Current root-mean-square values of stressed-deformed condition are detected in critical points of building, being established on model in these intervals, and speed of root-mean-average parametre value change in each critical point in interval of time Δt is defined using given dependence, at the same time remaining resource of time T to achievement of limit critical value of equivalent stress in critical point of building is detected using given dependence.

EFFECT: increased accuracy and reliability of time resource prediction to achievement of critical condition of building and reduction of cost and labour intensiveness of monitoring.

1 ex, 5 dwg

FIELD: construction.

SUBSTANCE: device consists of cylindrical hollow body, joined in its lower part to extended cap, upper part of body ends with stop coupling, annular recess of which hosts balls-fixators. Body cavity holds falling part of hammer, and in order to vary mass of hammer falling part, a set of weight is located in its cavity. Upper part of hammer is arranged with bulge for thrust of weight ring in process of lifting, and lower part of hammer ends with circular bore for location of balls-fixators in it.

EFFECT: possibility to replace expensive static tests for dynamic ones.

2 dwg

FIELD: construction.

SUBSTANCE: soil field tests are carried out with punch 6, test results are evaluated, particular value of limit soil resistance under pile foot is identified, at the same time casing pipe 3 is displaced, this displacement is fixed, particular resistance of soil is calculated on side surface of pile, and using superposition principle, bearing capacity of drilled pile is identified as sum of bearing capacity under pile foot and side surface. Method makes it possible, compared to prototype, to increase accuracy of drilled pile bearing capacity assessment up to 10%, to reduce number of piles in foundation grill by 7% as a result of high value of pile bearing capacity and to reduce number of tests by 6% due to high accuracy (validity) of assessment.

EFFECT: increased accuracy of drilled pile bearing capacity assessment.

1 cl, 3 dwg

FIELD: construction.

SUBSTANCE: in pit of appropriate depth, fragment of foundation and elements of seismic insulation made of loose materials are arranged, comprising seismic-insulation cushion under foundation and filling of pit pockets. Limit values of foundation vibration speed amplitudes, specified in process of design and permissible by conditions of its strength preservation, are determined. Explosion parametres are designed to obtain average amplitudes of foundation vibration speeds at the level equal to the limit values, for this purpose the expression VL=Vxyz=11.776X is used, with R2=0.815, where VL is vector speed of vibrations of average amplitudes of components (x,y,z) (Vxyz) of speeds transmitted by foundation soil through a layer of loose material of foundation, - reduced mass of charge, kg, R2 - coefficient of pairwise correlation, r - distance from explosion epicentre to the area of vibrations registration, m, h - depth of charge centre in well, m, QΣst - mass of charge in stage of explosion, kg, Knpc - coefficient that takes into account geological and relief conditions, varies from 1.0 to 3.0. On completion of explosive works, level of seismic action suppression is assessed, and if value of this characteristic is less than 2.7 points, thickness of cushion is increased, and/or composition of its material is chosen. Trials are repeated until amplitudes of foundation vibration speeds comply with conditions of its strength preservation.

EFFECT: improved reliability of building, structure seismic protection with reduction of capital and operational costs.

3 dwg

FIELD: construction.

SUBSTANCE: method to apply load to a pile, where an upper part is placed below the first pile section, at the same time the upper part is fixed to the first pile section. A bottom part is placed near the upper part, at the same time an area of separation is developed so that introduction of fluid medium under pressure into the separation area provides for a force striving to move the upper part and the bottom part from each other, and causes upward movement of the upper part in the first pile section. At least a part of a cross section in the upper part and at least a part of a cross section of the bottom part is open to ensure passage of materials on top from the upper part to the bottom from the bottom part. The upper part and the bottom part are placed prior to pile casting, at the same time materials for pile casting go through the open part of the cross section of the upper part and the open part of the cross section of the bottom part. If the upper part and the bottom part are separated, the upper part and the bottom part preserve their relative side position during separation, and the fluid medium is introduced into the separation area to apply the load to the pile.

EFFECT: reduced material intensity and labour intensiveness when testing higher bearing capacity of a pile.

28 cl, 7 dwg

FIELD: construction.

SUBSTANCE: using new elements - disconnection of hollow sections from a central anchor rod, provision of each hollow section, apart from the upper one, with a concentrically installed hollow stem with a support plate fixed on top of it and pulled coaxially via cavities of above sections and stems, and installation of force-measuring sensors in tiers above the pile head, and also installation of elastic pads into grooves in ends of hollow sections, - results in appearance of new properties in the proposed technical solution, namely, higher reliability, accuracy and duration of measurements of tangential heaving forces acting at driven piles in process of soil freezing, also by simultaneous measurement (with the help of the same force-measuring sensors) of friction forces of non-frozen soil, acting at hollow sections below the freezing limit and accounted in corrections to tangential heaving forces. Arrangement of force-measuring sensors in tiers above a pile head, making it possible to use removable plant-manufactured force-measuring sensors with high class of accuracy and to regularly calibrate them upon completion of each season of measurements, makes it possible to monitor reliability and accuracy of completed measurements.

EFFECT: possibility to carry out long-term measurements of tangential forces of frost heaving and friction forces of non-frozen soil increases reliability and accuracy of produced results due to taking into account a long row of measurement data in statistical processing.

2 cl, 5 dwg

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