Method of testing frozen ground by static sensing

FIELD: physics.

SUBSTANCE: method for testing frozen ground includes periodic immersion with stopping the probe in the soil mass and measuring the soil resistance to the penetration of the probe and the temperature of the soil. When stopping, after measuring the temperature of the frozen ground, thawing the ground is performed at the predetermined depth with the help of a heating element installed in the probe, after which the probe is pressed within the thawing zone of the soil and the resistance of the thawed ground to the penetration of the probe is measured.

EFFECT: providing the possibility of testing frozen ground with the determination of the mechanical properties and load-bearing capacity of permafrost soils, taking into account their thawing during static probing of soils, increasing the accuracy, reducing the laboriousness of the tests.

3 cl, 2 dwg

 



 

Same patents:

FIELD: measurement equipment.

SUBSTANCE: instrument includes sleeves for test soil specimens, which consist of rings, a water tray, dies, heat insulation and temperature sensors. With that, sleeves are arranged on telescopic shells of different height, which are installed on the tray.

EFFECT: instrument allows improving reliable determination of deformation of frost boil.

3 dwg

FIELD: construction.

SUBSTANCE: device for testing the compressibility of soil comprises the cylindrical body, perforated plunger and porous bottom. The instrument also includes the insert made of elastic material, provided with displacement sensors disposed between the case and sample under test. Insert permits the soil sample to expand under the action of load in transverse direction, besides the simultaneous compression of the soil sample and flexible insert is provided.

EFFECT: improving the accuracy of the results of measurements of the deformation module and coefficient of transverse deformations, simplifying the design of the instrument.

4 dwg

FIELD: testing equipment.

SUBSTANCE: invention relates to the field of "Physics of the material contact interaction" of hard flat body with a porous material environment, and is intended to determine its parameters of deformability and strength. Essence: the material environment is loaded with rigid flat perforated stamp with stepwise increasing load until the moment of loss of bearing capacity of the environment and sustainability of the stamp on it. The parameters of pressure pi and deformation Si of the environment at loading are controlled in time and a graph of test is plotted, by which the parameters of strength and deformability of the environment are determined. Each stage of deformation of the environment is kept constant in time to its conditional stabilization. Before setting the next steps of the deformation of the environment the elastic load cell is fixed with a locking screw of the load device. The device consists of a housing with a working chamber, fixedly mounted on the bottom of the chamber of the lower rigid flat perforated stamp, the working ring with a sample of the material environment, installed in the upper part of the working ring on the sample of the environment of the upper rigid flat movable perforated stamp and the loading device. The loading device consists of a rigid frame with an upper and lower beams and two guide racks, a pusher and a resilient load cell.

EFFECT: increased productivity of test of the environment on compressibility and strength.

2 cl, 2 dwg

FIELD: instrumentation.

SUBSTANCE: invention relates to physics of material contact interaction, namely to the method of establishment of marginal state of deformable compressing and extending load of the material medium. Essence of the invention: using the data of shift of the material medium loaded with steps of normal pressure at the depth h by the tangential load τi the curve τi = ƒ(pi) is plotted. The curve is linearised by a straight line to the crossing with the axis τI and the axis pi, on the axis τi the value of specific cohesion of the structured medium c = cstr is pre-set, on the axis pi the value of counter-pressure of the medium consolidation -pe = -cstr·ctgφstr is pre-set, and the angle φ = φstr of internal friction of the structured medium is determined. Coulomb Law τstr= pi·tgφstr+cstr is determined in the normal pressure range -(pe) ≤ pi ≤ (+ph), where ph = (γstr·h-cstr)ctgφstr - gravitational (household) pressure for the structured medium with the specific weight γstr, at the pressure pi>ph. The marginal state of the material medium is considered with the disturbed structure and described in terms of the relation τd = pd·tgφd+cd, and the marginal state of the material medium in general terms is described by a system of equations.

EFFECT: possibility of delimitation of marginal state of the material coherent medium with disturbed structural durability and establishing of regularity of the marginal state of the coherent medium outside its structural durability and Coulomb Law at the pressure pi above gravitational (household) ph, ie pi > ph.

3 dwg, 1 tbl

FIELD: construction.

SUBSTANCE: static, dynamic or vibration sensing is carried out preliminary at the selected points to the depth from 1 m with respect to the top of the earth fill. At the same time the samples of compacted soil of undisturbed structure are selected in order to determine the moisture and density of skeleton of the specified soil from several drilled wells at points at a distance of not more than 1 metre in plan from sensing points. Laboratory researches of standard compaction with definition of compacting factor depending on the density of soil skeleton, are carried out on the selected samples of soils from the body of compacted fill. Construction of correlation dependence is performed between the specified values of compaction factor and values of the resistance to penetration of standard cone into the soil during sensing, taking into account determinations previously performed in the laboratory followed by evaluation of compaction quality of the earth fill.

EFFECT: improving the accuracy of definition and identifying the areas of non-compacted soil for its subsequent local postcompaction.

3 cl

FIELD: measurement equipment.

SUBSTANCE: invention relates to the field of "Physics of material contact interaction" and serves to determine gravity (compression) pressure in a massif of material medium of certain density. The method to determine gravity pressure of material medium in a massif and its natural density consists in the fact that at the specified depth h (cm) of the material medium massif using field methods of engineering survey, they determine the angle φsrt of the inner friction and specific adhesion csrt of the medium of integral structure under conditions of gravity (compression) pressure pc. At the same time the value of gravity pressure in the massif of elastic cohesive plastic soil medium is determined according to dependence pcG=cGstrcosφGstr(1sinφGstr)/(1+sin2φGstr), and density of soil medium is calculated as ρGstr=cGstrsinφGstrgh(1sinφGstr1+sin2φGstr) at specific weight γGstr=cGstrsinφGstrh(1sinφGstr1+sin2φGstr), where g - acceleration of free fall of a body under gravity conditions (cm/s). Then the value of gravity pressure in the massif of elastic resilient anisotropic peat medium is determined using dependence pcP=cPstr1tgφPstr, and density of peat medium is calculated as ρPstr=cPstrgh(1tgφPstr) at specific weight γPstr=cPstrh(1tgφPstr)=pcP/h.

EFFECT: possibility to determine the value of gravity (compression) pressure in a massif of material medium by data of its strength parameters φstr and cstr in integral condition, and also value of specific weight γstr and density ρstr of medium under conditions of gravity of Earth surface.

2 dwg

Soil test device // 2548063

FIELD: construction.

SUBSTANCE: device includes a loading die, a load application unit, a thrust system and a measurement system. The die is made in the form of a stiff structure of a square shape. Under the die there arranged is an elastic plate with dimensions of the die in a plan view, with thickness of 0.05-0.1 of the size of the die sides and elasticity modulus of 30-50 MPa. A rectangular coordinate grid is applied to lateral sides of the elastic plate. The measurement system includes a recorder of the applied load and a die settlement recorder. On the lateral sides of the die there rigidly fixed on its symmetry axes by means of brackets are video recorders of deformation of the elastic plate with a possibility of complete vision of lateral sides of the elastic plate.

EFFECT: simplifying and cheapening of determination of distribution of reactive voltage of a soil foundation at any arbitrary points along the die bottom and improving reliability of results at one test.

2 dwg

FIELD: measurement equipment.

SUBSTANCE: invention relates to the field of material interaction physics, namely to the method of determination of gravitational (local) pressure in the massif of connected material medium. The value of gravitational pressure is determined by the relation pl=(γ·h-cstr)ctgφstr, where γ - specific gravity of the material medium, h - depth of determination of pressure in the medium massif, cstr - structural specific cohesion of the medium, φstr - angle of internal friction of the structured medium in a natural occurrence.

EFFECT: improvement of accuracy of determination of local pressure value.

1 dwg

FIELD: construction.

SUBSTANCE: invention relates to the field of construction and is intended for use in engineering and geological survey in order to partition soil thickness in process of rotary drilling and determination of mechanical properties of soils in field conditions. A sound procedure plant, comprising a vehicle, on the platform of which there is a mast with a spinner, a hydraulic system providing for operation of crane drilling equipment, differing by the fact that with the purpose to expand functional capabilities and to increase accuracy of measurements, the plant is equipped with a measurement device, a device of axial loading and a laser range finder, a measurement device, one end of which is connected to the spinner shaft, the other one via a device of axial loading with a tail of a drilling string, comprises two force sensors, measurement of vertical movement of a drilling tool is carried out using a wireless laser range finder and a reflector fixed on the mast, measurement of drilling string and soil weight on its side surface is carried out using a force sensor, speed of rotation of a drilling tool is determined by means of analysis of radio signals recorded during rotation of the measurement device.

EFFECT: expansion of functional capabilities, increased accuracy of measurements.

11 dwg

FIELD: construction.

SUBSTANCE: testing method of carrying capacity of pile consists in the creation of stepwise increasing load on the soil through the pile and die before the conditional stabilization at which the upset speed doesn't exceed the specified value, during time specified, depending on type of soil, in the simultaneous upset recording with control precision equal to 0.01 mm, and for each stage of loading - in the construction of graphs of upset change in time, having the exponential form with curved zone, characterizing the upset speed before the initiation of conditional stabilization, and with flat zone. Upset registration at each stage of loading is performed at regular time intervals, which are specified within the limits of 3-5 min. Schedule of upset change in time (exponential curve) is built by upset values, uniformly registered in each time interval. The interval with the registered upset speed equal to 0.05 mm/min, according to which the new criterion of conventional stabilization is set, is determined at the curved portion of exponent. Time prior to conventional stabilization is determined by the number of intervals at the curved area until the specified time interval. Time of observation over the upset speed not exceeding 0.05 mm/min, is determined by the number of time intervals at the remaining segment of the curved area of exponential curve before the initiation of the flat area. For different types of soils the specified number of observation intervals over the upset speed is maintained in the ratio L1: L2=1/T1:2/T2, where T1, L1 - interval time and number of intervals, respectively, during time of observation over upset speed during pile testing on the sandy and clayey soil from solid to low-plasticity consistency; T2, L2 - interval time and number of intervals, respectively, during observation over the upset speed when testing the pile on the clay soil from solid to low-plasticity consistency.

EFFECT: reduction of time and cost of tests due to bringing the results of upset registration of pile to the actual state of soil of the respective type.

2 cl, 2 ex, 5 dwg

FIELD: engineering investigations in building, particularly devices for determining deformation and strength properties of ground in well.

SUBSTANCE: device comprises probe (working tip), control-rod, pipeline, communication line, loading jig and measuring station. Probe includes hollow cylindrical body with bottom and cap filled with working liquid, elastic shell sealed from body bottom and top. Formed in non-fixed elastic shell area are perforations. Piston with rod is installed in upper part of hollow body above working liquid. Rod passes through cap in sealed manner. Rod is connected with control rod so that piston may move in axial direction. Formed above piston is cavity connected to pipeline. Hollow body has bottom in which air-tight plug is installed. Measuring device is made as linear piston displacement transducer. Through orifices are formed in hollow body wall near body bottom. Arranged from body outside are vertical or inclined grooves aligned with through orifices by lower ends thereof. Air-tight plug is provided with adjustable rest for restricting piston stroke.

EFFECT: simplified structure of probe and measuring devices, increased operational reliability and improved validity of obtained data.

2 cl, 1 dwg

FIELD: building, particularly building-and-engineering researches to investigate deformation ground properties.

SUBSTANCE: device has thrust structures including bearing plate connected with base by supports, mechanism for applying axial load to ground sample mounted on base and dynamo-metering structure. Dynamo-metering structure is made as frame formed by two longitudinal tie rods and two transversal beams. Cross-section of upper beam has the shape of horizontal H-bar along axis of plant symmetry. Strain gage transducers are arranged on working shoulders of H-bar, support part for sensing forces to be measured is connected to wall thereof.

EFFECT: increased measuring accuracy, reduced measuring time.

4 dwg

FIELD: mining industry.

SUBSTANCE: stand has device for pumping liquid and detachable shell, wherein model of filtering environment is placed. Detachable shell is connected to liquid forcing plant and has replaceable impenetrable elements for adjusting value of contact area of outer surface of filtering environment to liquid, made in form of inserts and ring isolators.

EFFECT: higher precision.

8 dwg

FIELD: construction, particularly engineering investigations to determine earth strength and deformation characteristics.

SUBSTANCE: method involves rotary driving hollow pipe string for the test depth with the use of boring rig so that minimal vertical load is applied to the pipe string. Pipe string is provided with screw punch blade having constant pitch and varying blade thickness which increases in down-top direction. Blade is provided with pressure transducers flushed with lower surface thereof. Pressure transducers are connected with original ground by communication cable. Module of deformation is determined with the use of well-known method by stabilized pressure value of each transducer after punch driving completion and from predetermined rate of deformation under each transducer. Rate between punch immersion depth per one turn h and pitch thereof a is synchronized up to obtaining value of h/a≤1.0 before reaching test depth for instance with the use of screw pair. Non-stabilized pressure values under each transducer are recorded immediately before punch driving stop.

EFFECT: increased measuring reliability and output.

5 cl, 1 dwg

FIELD: construction, particularly engineering investigations used in rapid building erection and reconstruction.

SUBSTANCE: method involves driving screw-in punch made as a blade in soil with the use of boring rig up to reaching soil test level simultaneously with driving screw-in anchor in soil, wherein screw-in punch and anchor are mounted on lower end of hollow pipe string so that they may perform limited movement one relative another and relative the pipe string with upper pipe string end secured to soil; applying predetermined load value to the punch; measuring punch immersion value at predetermined time intervals up to soil settlement stabilizing under the punch; applying next load value. Load application and measuring, as well as punch immersion method is performed in direct contact with punch of load applying device and linear displacement transducers with the use of feedback link connected with day ground. Load is applied to punch from day ground through technological hollow rod passing through pipe string hollow before test start. The rod is provided with load transducer cooperating with the punch and linear displacement transducers cooperating with the anchor. The anchor is used as reference point. Soil is tested in mode of set soil displacement under the punch by conditionally momentary deforming of soil under the punch in steps equal for soil to be tested. On reaching deformation step total load applied to punch and additional punch immersion are measured at predetermined time intervals. On reaching conditional load stabilizing on one step one will shift to the next step of soil deforming. Rate of change of specific pressure applied to soil with time is used as criterion of conventional load stabilizing on each step.

EFFECT: possibility to measure load applied to operating member and immersion thereof near soil test level, reduced test time.

5 cl, 4 dwg

FIELD: construction, namely engineering surveying to be carried out during building and building structure reconstruction, particularly accelerated surveying methods.

SUBSTANCE: device comprises hollow pipe string parts screwing up in ground with the use of boring rig. Pipe string parts are connected with each other by thread connections and additionally with pins. Screw impress with tail piece and screw marker with case are mounted on lower pin so that they may perform limited axial movement. Auxiliary rod is inserted in pipe string interior up to reaching impress tail piece. Lower end of auxiliary rod is provided with load sensor cooperating with marker case. Sensors communicate with day surface. Hydraulic power cylinder is installed between swivel head shaft and connected with upper end of auxiliary rod through centralizer having cut for cable passing. Each pipe string part additionally has inner left-handed thread formed in right-handed outer thread and annular inner seat located at lower end thereof. Hollow nipple is freely installed inside each pipe string part. Nipple has mating left-handed thread made on lower end thereof and mating outer annular seat located on upper nipple end. The annular nipple seat has socket, for instance adapted for socket wrench receiving to tighten pipe string parts by means of left-handed thread by unscrewing right-handed one during impress and marker removal. Marker case is provided with taper collet secured to lower end thereof so that taper collet surrounds impress tail piece by springing blades thereof. Packing gland in installed in taper collet interior. Screw impress is secured to tail piece by coaxial connector and shear ring having shear resistance less than that of other tail piece connections.

EFFECT: increased reliability during device driving in soil and drawing out from soil and increased accuracy of obtained information.

2 cl, 6 dwg

FIELD: construction technology; graphical methods.

SUBSTANCE: combined profiles of stresses are built at the plane of contact of rigid dye with flat-deformed base taking elastic state of base combined with plastic one taken into account. Law of shift of bounds of these states at area of contact is determined depending on raise in external average pressure (pav) while taking distribution of elastic contacts of stresses σzke according to concave parabola law and distribution of contact stresses σzn of shift under smooth sole of stencil according to straight line rule. The straight line crosses concave parabola of elastic stresses at the bound of area of elastic and shift deformations. Parameters of carrying ability of base depending on internal friction angle φ, engagement c and volumetric weight γ are calculated for stencils of known shape, sizes, rigidity and degree of roughness of its sole. Contact tresses are determined from coordinates of profiles. Profiles after being built are represented as mirror reflection relatively axis of ordinates and profiles of elastic and shift contact stresses are got under surface of stencil.

EFFECT: solution of combined elastic-plastic contact problem.

3 dwg

FIELD: investigating or analyzing materials.

SUBSTANCE: method comprises plane-parallel deforming of soil base by external pressure and determining the specific bond and angle of internal friction of the soil base.

EFFECT: enhanced precision.

2 dwg

FIELD: construction engineering.

SUBSTANCE: method concludes in determining parameters of physical and mechanical characteristics: internal friction angle φ, specific adhesion c and volumetric weight of depth-uniform ground base and anisotropic turf deposit γ. Value of average external pressure ρave applied to base through flat hard template of average size is calculated, which average pressure corresponds to moment of phase shift of base from one state to the other to determine specific processes of sharp growth of deposits, reduction in strength and possible loss of stability in total and to determine carrying capacity of flat-deformed base when pattern of operation of ground base is seen as linearly deformed space and turf deposit - as Fuss-Winkler model of local elastic deformations. In this case new phase conditions of ground are found and phase states under turf deposit load are determined depending on sizes and shapes of hard flat templates.

EFFECT: improved precision of calculation.

11 dwg

FIELD: investigation of foundation soil in situ, particularly to construct and reconstruct existent buildings and building structures.

SUBSTANCE: method involves monoaxial ground sample compression in compression apparatus along with prevention of radial expansion thereof, wherein the ground sample is tested in stress release regime; plotting compression curve after each stage termination by final stress values and corresponding sample deformations. As predetermined sample deformation value is achieved additional ground sample settlement is restricted by partial stress release to approximate value thereof to conditional stress stabilization or sample deformation value.

EFFECT: reduced ground investigation time.

4 dwg

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