196 results about "Permafrost Region" patented technology

The invention provides a large frozen soil model test system with a moisturizing function and a frost heaving test function. A moisturizing system and a refrigeration system of the model test system are arranged in a model tank box body; a loading system capable of vertically moving is arranged at the top of the model tank box body; a temperature field test device is arranged at the periphery of the refrigeration system; a frost heaving three-dimensional stress-strain test device is arranged on the inner side wall in the model tank box body; and a frost heaving and thaw collapse observation device is fixedly arranged at the top of the model tank box body. The large frozen soil model test system has the beneficial effects that a platform for scientific research is provided for researching the physical and mechanical properties of artificially frozen soil and optimizing an artificial freezing method; the large frozen soil model test system can be widely applied to freezing method construction model tests in the fields of geotechnical engineering, underground construction, traffic engineering and the like, for example, simulation tests are carried out on underground construction such as shield tunnel inlet and outlet freezing reinforcement, contact passage freezing method construction, and deep foundation pit freezing support; in addition, the natural frozen soil can also be simulated by adjusting control parameters of refrigerating machines; and large frozen soil model test system is applied to research on damages and effects on buildings and structures caused by seasonally frozen ground and frozen soil in permafrost regions.

The invention discloses a method and a device for exploiting natural gas hydrate in a permafrost region. The device comprises a water-pumping depressurization system, an underground in-situ combustion heating system, a gas collection system and a control system. The water pumping depressurization system comprises a water delivery pipe, a deep-well pump and a gas-liquid separator, wherein the deep-well pump is arranged at the bottom of a vertical well; and the gas-liquid separator is connected with the deep-well pump by the water delivery pipe. The underground in-situ combustion heating system comprises an electronic ignition device and an oxygen-containing gas conveying pipe, wherein the electronic ignition device is connected with a ground power supply by a power switch; and the oxygen-containing gas conveying pipe is connected with an external gas supply system and paved from the ground to the electronic ignition device through the vertical well. The gas collection system comprises a gas collection pipe which is arranged at a well head of the vertical well. The control system comprises a pressure sensor, the power switch and a regulation valve, wherein the regulation valve is arranged on the oxygen-containing gas conveying pipe; and the control system controls the aperture of the regulation valve and the on and off of the power switch according to a pressure, which is measured by the pressure sensor, of the vertical well. By the invention, the synchronous continuous exploitation of depressurization and underground in-situ combustion heating can be realized.

The invention discloses a method and device for simulating an experiment of permafrost region natural gas hydrate mining through replacement of CO2 / N2. The simulation method includes the steps of core treatment and installation, pipe connection and pressure testing, vacuumizing treatment, injection of distilled water and CH4 in a response model and synthesis of natural gas hydrate. CO2 gas is injected after the synthesis is ended, and CH4 is displaced; CO2 / N2 is injected in the response model to perform replacement mining; after replacement, gas is collected, and quantitative analysis is performed; and the experiment simulating device comprises a hydrate response model unit, a gas supply unit, a liquid supply unit, a confining pressure control unit, an environment control unit, a vacuum treatment unit, a gas detection unit, a gas-liquid separation unit, an information acquiring and processing unit and an auxiliary unit. The method and device for simulating the experiment of the permafrost region natural gas hydrate mining through the replacement of CO2 / N2 can simulate external environment of the natural gas hydrate really, perform the experiment of the permafrost region natural gas hydrate mining through the replacement of CO2 / N2, furthermore can also perform the mining experiment through a heat injection method and a pressure drop method, and provide guidance for mining of the natural gas hydrate.

The invention discloses a high-altitude permafrost region porphyry type copper polymetallic mine exploration technology combination method which can improve the prospecting success rate. The method includes the following steps: A, determining a metallogenic system as a collision orogenic metallogenic system in cooperation with a collision orogenic regional geological background according to the output spatial-temporal characteristics of a permafrost region porphyry type copper molybdenum mine typical mineral deposit and numerous mineral occurrences; B, measuring stream sediments with the aim of observing geochemical halos on the upper portion of a porphyry body mineral body, defining a magnetic abnormity region through high-accuracy magnetic measurement, and defining a remote sensing predicting region with the aim of forecasting mineral resources such as copper, lead and zinc through high resolution remote sensing; C, conducting 1:1 soil profile or petrochemistry profile, groove and well exploratory exposure on explored abnormal or mineralization clues; D, defining a mineralized region or the mineral body; E, verifying the defined mineralized region or mineral body through drilling; F, determining the mineral body or the mineral deposit. By means of the method, the prospecting working period of a porphyry type copper molybdenum mineral region can be shortened, and meanwhile numerous metal mineral bodies can be explored.

Construction features of roadbed are as follows: building vent-pipes perpendicular to direction of roadbed in certain depth of road embankment; installing ventilating units of automatic controlling temperature at end part of vent-pipe; setting up thermal-protection material between vent-pipes / entire up part of vent-pipes with earth material being covered and tamped. The said automatic controlling ventilating units carries out heat exchange between inside roadbed and airflow in low temperature outside. The thermal-protection material protects ever frost effectively. Thus, the invention prevents frost heave and thaw collapse caused by season change so as to keep stability of roadbed in high level. The invention solves issue of carrying construction in zone of frozen earth.

A radio frequency applicator and method for heating a hydrocarbon formation is disclosed. An aspect of at least one embodiment disclosed is a linear radio frequency applicator. It includes a transmission line and a current return path that is insulated from the transmission line. At least one conductive sleeve is positioned around the transmission line and the current return path. The transmission line and the current return path are electrically connected to the conductive sleeve. A radio frequency source is configured to apply a signal to the transmission line. When the linear applicator is operated, a circular magnetic field forms, which creates eddy current in the formation causing heavy hydrocarbons to flow. The heat is reliable as liquid water contact is not required. The applicator may operate in permafrost regions and without caprock.

The invention discloses a preparation method of an artificial rock core for simulating a permafrost region hydrate stratum skeleton. The method comprises the following steps: S1: acquiring the components, grain composition, density, porosity and permeability of a stratum to be simulated; S2: determining the range of the proportion of base sand to a conditioning agent according to the components of the stratum to be simulated, and determining the grain composition of the base sand according to the grain composition of the stratum; S3: setting a rock core size, and determining the use amount of the base sand and the conditioning agent according to the set rock core size and the density of the stratum to be simulated; S4: with the porosity and the permeability as target values, setting the influence factors and the level values of the target values, and designing an orthogonal test formula graph; and S5: according to the orthogonal test formula graph, pressing the rock core in a compression molding way. The rock core prepared by the preparation method approaches the real permafrost region natural gas hydrate stratum in basic physical parameters, and the pore distribution approaches the normal distribution characteristics of the real stratum, therefore, the method is conductive to large-batch production for comparison and repeated test.

The invention discloses the application of a thermal pipe-crushed stone protection slop composite roadbed with the functions of temperature reduction and thermal insulation in a broad width high-grade road. The composite roadbed comprises sealed L-shaped thermal pipes, crushed stone protection slops, insulating layers and roadbed filling, wherein the crushed stone protection slops are laid on side slopes on both sides of the roadbed until reaching a natural earth's surface; the L-shaped thermal pipes are embedded in the roadbed filling, and ammonia or nitrogen is used as working media in the pipes; and the insulating layers are embedded in the underground roadbed filling. By utilizing the changes of angles of the condensation segments and the evaporation segments of the L-shaped thermal pipes in the roadbed, the composite roadbed lowers the temperature of soil bodies under the center of the roadbed; and by combining the advantages of the crushed stone protection slops and the thermal insulating layers, the composite roadbed increases the cold energy suction volume in a cold season and effectively controls the heat absorption capacity in a warm season, thereby realizing the temperature reduction of the underlying soil bodies of the broad width high-grade roads, balancing a temperature field, increasing the upper limit of frozen soil, and meeting the special requirement of roadbed stability of perennial high temperature permafrost regions.

The invention relates to a test device for simulating permafrost region well heat insulation or heating. The test device is characterized in that a test tank is a circular interlayer barrel body consisting of an outer ring, an inner ring, a top plate and a bottom plate, a soil body is filled in an interlayer, a refrigerating liquid circulation passage is arranged inside the top plate and the bottom plate, is connected with a refrigerating temperature control device and is in contact with the soil body, water is filled in a water tank, the water tank is arranged in the test tank, a heat insulation barrel is placed between the water tank and the test tank, heat insulation covers are placed on and under the water tank, a water replenishing device is connected with a water tank bottom plate through a water replenishing pipe, a water pressure gauge is arranged on the water replenishing pipe, a water pumping device is connected with a water tank top cover through a water pumping pipe, the water pumping pipe is inserted into water of the water tank, a flow meter is arranged on the water pumping pipe, a heating temperature control device is connected with a heating pipe through a conducing wire, the heating pipe is inserted into the water of the water tank, and temperature sensors are arranged in the solid body and the water of the water tank and are respectively connected with a digital collecting instrument. The test device has the advantages that the permafrost region well is simulated, the reasonable well diameter, the water pumping speed, the heat insulation thickness and the power of a heating device are obtained, and the goals of energy saving and environment protection are reached.

The invention relates to the technical field of road construction projects in permafrost regions, in particular to a method for calculating the frost heave characteristics of deep seasonal frozen soil subgrade. The invention is to overcome the defects that in the prior art, the study on the microscopic mechanism of a freezing process is not deep enough and does not have a meaning of guidance. The solution is the method for calculating the frost heave characteristics of the deep seasonal frozen soil subgrade which comprises the calculations based on the following factors, (1) the effect of soil particle size, (2) the effect of soil density, (3) the effect of temperature, and (4) the effect of water.

The invention relates to a method of reducing the concrete hydration heat of a cast-in-place pile in a permafrost region. The method comprises the following steps of (1) constructing in the permafrost region, and digging a foundation pit for the cast-in-place pile according to a design requirement; (2) computing the hydration heat release of concrete needed by the cast-in-place pile according to a routine method, and computing the various needed parameters of a hot stick according to the routine method; (3) binding a reinforcement cage according to the design requirement, and fixedly arranging a sleeve at a required design position in the reinforcement cage after the binding is completed; (4) arranging the hot stick in the sleeve, and hoisting the reinforcement cage into the foundation pit for the cast-in-place pile after fixed arranging of the hot stick is completed according to a confirmed hot stick embedding length; (5) preparing and stirring the concrete which is mixed with an anti-freezing agent according to design grade requirements, pouring the concrete in the foundation pit for the cast-in-place pile, immediately covering with a thin film after the pouring is completed, and then covering with a straw curtain or heat preservation materials for heat preservation; (6) pulling out the hot stick and carrying out follow-up construction according to the routine method. According to the method of reducing the concrete hydration heat of the cast-in-place pile in the permafrost region, disclosed by the invention, the refreezing time of frozen soil can be reduced, and the construction is simple and convenient.

The invention discloses a seasonal permafrost region self-thermoregulation returning energy-consuming slope supporting structure and a construction method and belongs to the technical field of seasonal permafrost anchor-plate retaining. The seasonal permafrost region self-thermoregulation returning energy-consuming slope supporting structure comprises a lattice beam, an anchor rod, a spring and a thermal insulation structure and is characterized in that the anchor rod is punched into a slope, anchoring slurry is injected with pressure, the anchor rod is anchored in a stable soil layer, a thermal insulation structure and a geogrid are sequentially paved from the slope surface to the exterior, a mortar surface layer is sprayed, a gird beam is constructed on the slope surface, the anchor rod penetrates a cross position of the gird beam, a base plate and a spring sequentially sleeve the anchor rod, the anchor rod is anchored on gird beam through an anchorage device, vertical water discharging channels are horizontally arranged with the interval of certain distance along the slope surface, a intercepting ditch is arranged at the slope top, and a drainage channel is constructed at a slope toe. The seasonal permafrost region self-thermoregulation returning energy-consuming slope supporting structure has self-thermoregulation thermal protection and heat insulation, expansion and shock reduction and self-returning supporting performances, timely discharges moisture, effectively solves slope instability caused by frost heaving thaw collapse disasters. The construction method is simple, strong in feasibility, quick in construction and low in cost.

A method for conducting active thermal protection on a tunnel shallow buried section in a permafrost region using a hot bar cluster comprises the following steps: collecting meteorological data in a tunnel site area; combining construction geological exploration data to ascertain the basic thermophysical parameters, permafrost types, superior limit depth, ground temperature annual mean changing depth and annual mean changing depth of the surrounding rocks in the tunnel shallow buried section; determining the burying range and the burying depth of the hot bar cluster, arranging the hot bars in an equilateral triangle mode, and determining the length of the hot bars according to the burying depth; and burying the hot bars by means of drilling insertion method, promoting the refreezing of the surrounding rocks in the hot-melt circle of the tunnel shallow buried section and the rapid forming of frozen earth seepage-proofing curtain in the tunnel surrounding rocks by means of the 'active' temperature-reduction property, that the hot bars can actively extract heat in the surrounding rocks out and send the heat into the atmosphere, of the hot bars, and conducting the thermal protection on the tunnel shallow buried section structure. The method for conducting the active thermal protection on the tunnel shallow buried section in the permafrost region using the hot bar cluster can accelerate the refreezing of the surrounding rocks in the hot-melt circle of the tunnel shallow buried section, shorten the freeze thawing circulation period and resolve the problems that the refreezing cycle of the surrounding rocks in the tunnel shallow buried section is long, a waterproof and drainage system is prone to becoming invalid and a freeze-thaw damage occurs in a supporting structure.

The invention discloses ultra-low-temperature drilling fluid for deep sea and permafrost region drilling. The ultra-low-temperature drilling fluid is prepared from the following components in parts by mass: 100 parts of water, 2-7 parts of a plugging-inhibition type well wall stabilizer, 0.05-0.8 part of a tackifier, 0.05-0.5 part of an encapsulating inhibitor, 1-10 parts of a filtrate loss reducer, 10-40 parts of a hydrate inhibitor, 0-1 part of lecithin, 0-4 parts of paste mud, 0-3 parts of a lubricating agent and 0-150 parts of a weighting agent. According to the drilling fluid disclosed by the invention, with physical and chemical properties of the plugging-inhibition type well wall stabilizer, the synergistic effect that a well wall is blocked and the mud shale hydration is inhibited is achieved, so that pore pressure transmission can be effectively slowed down and mud shale hydration can be inhibited, and good well wall stability can be kept in the deep sea and permafrost region drilling; good rheological behavior and filter loss performance can still be kept when the temperature is -10 DEG C; the generation of natural gas hydrates can be effectively inhibited; and the lubricating performance is good.

The invention relates to a novel drilling pile casting and a manufacturing method thereof. In the construction of bridge works, the problem of pore-forming of a bridge drilling pile in a permafrost region puzzles technicians all the time; under the geological condition of permafrost, the impact force of the drill head of a drilling machine produces thermal disturbance in a hole when the drilling machine reaches the permafrost if the single casting and conventional construction are adopted, hole collapse is caused owning to melting close to the permafrost in the hole, and the pore-forming rate of the drilling pile is difficult to guarantee, thus the construction efficiency is low, the construction period is prolonged, the cost is high, and the construction quality is difficult to guarantee. The novel drilling pile casting comprises a group of small castings (2) for an inner layer, the small castings are welded in segments, the outer side of the small castings for the inner layer is provided with a group of large castings (3) for an outer layer, and fixing slurry (1) is filled between the small castings for the inner layer and the large castings for the outer layer. The invention is applied to the pore forming of the permafrost region in the construction of the bridge works.

The invention discloses a distributed roadbed settlement monitoring system and method for high-altitude permafrost regions and relates to observing devices and methods in the field of civil engineering monitoring. The purpose is to solve the problems that according to an existing roadbed settlement monitoring method, the measurement range is limited, durability is poor, and working stability is poor under an extreme environment. Multiple longitudinal continuous steel strand reinforcement distributed sensor optical fibers are distributed in parallel, multiple transverse fixed-point type polymer reinforcement distributed sensor optical fibers are distributed in parallel, the longitudinal sensor optical fibers are perpendicular to the transverse sensor optical fibers, the transverse sensor optical fibers penetrate through temperature measurement steel tubes, fiber bragg grating temperature sensors are fixed to the outer walls of the temperature measurement steel tubes, a brillouin time domain analysis system is used for obtaining the stress distribution of the sensor optical fibers, a fiber bragg grating interrogator is used for obtaining the temperature distribution of the fiber bragg grating temperature sensors, and the volume of roadbed settlement is obtained according to obtained data. The distributed roadbed settlement monitoring system and method is suitable for monitoring roadbed settlement of the high-altitude permafrost regions.

The invention discloses a type prediction method of vegetation in a high-altitude permafrost region, and relates to the field of geography. The method comprises the steps that the survey data of characteristics of the vegetation in the permafrost region of Qinghai-Tibet Plateau is obtained; bio-climatic parameters are obtained; according to an NDVI data set, NDVI parameters are obtained; according to a digital elevation model (DEM), the slope, the slope direction and the profile curvature at each grid pixel element point in the permafrost region of Qinghai-Tibet Plateau are obtained; the elevations, the slopes, the slope directions and the profile curvatures are used as topography parameters; the parameters with the correlation coefficients larger than 0.8 are selected in the bio-climatic parameters, the NDVI parameters and the topography parameters through a principal component analysis method, and vegetation classification parameters are obtained; according to the survey data of the characteristics of the vegetation, the vegetation classification parameters, climate scenarios data and a climatic system mode, the types of the vegetation in the permafrost region of Qinghai-Tibet Plateau are obtained through a decision tree classification method. By means of the method, the type distribution prediction, in the mode of ten types of ten categories of climatic systems and four types of climate scenarios in 2050 and 2070, of the vegetation in the permafrost region of Qinghai-Tibet Plateau can be achieved.

The invention discloses a composite lining technology suitable for a permafrost highway tunnel. The technology of three layers of linings, two layers of water preventing and three layers of heat preservation is adopted, and the technical problem that a high-grade long and big highway tunnel constructed in the permafrost regions suffers from freeze-thaw damage is effectively solved. According to the lining structure of the technology, a primary lining structure, a waterproof heat preservation layer, a secondary lining structure and a heat preservation waterproof layer are sequentially arrangedbelow a support structure. The lining technology mainly comprises primary die forming of low-temperature early strength concrete, waterproof layer construction, heat isolation layer construction, secondary lining of reinforced concrete and hole interior decoration. Compared with a traditional tunnel lining technology, air temperature changes caused by human factors within a secondary lining can beisolated from a perpetually frozen soil layer in the lining technology, it is guaranteed that lining back water can be drained in time, frost heaving is avoided, adopted materials and machines are simple, and operation and construction are easy; and the later project quality problem is solved, the tunnel safety accident probability is reduced, and meanwhile the project progress is guaranteed.

The present invention relates to a method for checking anti-frost heaving damage of a slope concrete lining layer of a water conveyance canal in winter. The method is applied to the design of an open channel water conveyance canal and to perform a force analysis on a slope concrete lining layer under an 5 of canal base soil frost heaving. The method comprises: by using a canal slope concrete lining layer as a member with a slope foot as a fixed hinge support and a water level surface as a movable hinge support, establishing a mechanical model of checking the anti-frost heaving damage of a canal slope concrete lining layer; and determining, according to a stress generated by a transverse bending effect or / and a stretch-bending combination effect of the member and axial tensile strength of concrete, whether the slope concrete lining layer can resist the damage generated by a frost heaving effect. According to the method for checking anti-frost heaving damage provided by the present invention, influence of interaction between canal slope bidirectional freezing as well as a concrete lining layer and canal base soil deformation is considered; and a deficiency of a checking method of anti-frost heaving damage capacity of a slope concrete lining layer under the circumstance of water conveyance by a concrete canal in a permafrost region is made up.

The invention provides a deformation monitoring datum point device applicable to permafrost regions and a method for mounting the deformation monitoring datum point device. The device comprises a datum rod and a cylindrical sleeve. The datum rod is fixedly connected with a datum rod base, an inner hole is arranged at the bottom of the sleeve, the diameter of the inner hole is matched with that of the datum rod, and the diameter of the datum rod is smaller than the inner diameter of the sleeve. The method includes placing the datum rod in a drilled hole; filling clay mortar in the drilled hole until the depth of the filled clay mortar meets a certain requirement; sleeving the sleeve on the datum rod properly so that the top of the sleeve is lower than that of the datum rod; filling clay mortar in the drilled hole compactly; and filling lubricating materials which are not easy to freeze in cold seasons in a permafrost region between the datum rod and the sleeve so that mounting of the deformation monitoring datum point device is completed. The deformation monitoring datum point device and the method have the advantages that only the position of the sleeve can be changed in seasonal freezing and thawing processes, but the position of the datum rod used as a fixed point is not changed; interference to a datum point due to seasonal freezing and thawing effects of the permafrost region is effectively avoided, so that deformation monitoring accuracy is guaranteed; and the deformation monitoring datum point device is high in field mounting speed, simple and convenient to construct and high in reliability.

The invention relates to a construction method for a rubble stone-ventilating board composite roadbed of an expressway at a permafrost area. The method includes the steps that firstly, rubble stone is prepared, after a bottom cushion layer is detected to be qualified, the rubble stone is poured for filling at a time, and then filling shaping, leveling and padding, and static pressure rolling are conducted; gravels are poured on the rubble stone for filling, after leveling and static pressure rolling, a water-permeable geotextile is laid on a gravel layer, and a sand-gravel cushion and a geogrid are laid on the water-permeable geotextile, so that roadbed construction is completed; a high-strength waterproof film is laid on the top face of a roadbed, pouring formworks for ventilating boards are mounted, a reinforcement fabric is manufactured, transverse PVC ventilating pipes are arranged, pouring is completed, and after top galling, curing and demolding are conducted. By means of the construction method, the temperature of the top surface of the rubble stone roadbed can be lowered, and the convection heat exchange effect inside the roadbed is enhanced; after the ventilating boards are additionally arranged on the rubble stone layer, the upper temperature of the rubble stone layer is lowered through the ventilation effect, the temperature difference between the top and the bottom of the rubble stone layer is increased, and the convection heat exchange effect of the rubble stone layer is enhanced.

The invention provides a method for maintaining thermal stability of a permafrost foundation subgrade by using a solar refrigeration device. The method relates to the solar refrigeration device and an arrangement method of the solar refrigeration device, wherein the solar refrigeration device comprises condenser pipes; cooling fins are mounted on the peripheries of the condenser pipes; an evaporator is arranged at one end of each condenser pipe, and a solar refrigeration driver is arranged at the other ends of the condenser pipes; and the evaporators are metal single pipes coated with heat-absorbing materials on the outer surfaces. During an application of the solar refrigeration device, the evaporators are partially buried under the permafrost foundation subgrade in an independent vertical arrangement manner or mutual communication manner, and the condenser pipes and the refrigeration driver extend out of the permafrost foundation subgrade. According to the method, whole year operation and cycle operation of the solar refrigeration device are realized by means of climatic features of a plateau permafrost region, initiative refrigeration can be realized particularly in a warm season when the permafrost is melted, and the method is used for maintaining the thermal stability of the permafrost foundation subgrade, and phenomena of hot melt sinking, inclining, cracking and the like of the permafrost foundation subgrade can be effectively prevented.

The invention provides a bored concrete pile construction method of a permafrost layer, which relates to the construction field of power transmission tower footings, with the development of power transmission engineering, power transmission lines extend to high altitude permafrost regions, but construction methods suitable for permafrost region tower footings are far from perfection, and bring large difficulty to the construction, therefore, the invention provides the following scheme: pile holes are rapidly excavated by means of heat balance in the state of nature, anti-caving hole retaining walls are poured thereto, cages of reinforcement are arranged in the pile holes and surfaces of the retaining walls in parallel, and concrete bored concrete piles are poured in layers rapidly, and the invention has benefits of simple method, convenient construction, easy implementation, stable permafrost layer and high efficiency of construction.

The invention relates to a plant matching mode suitable for vegetation recovery of a permafrost region project slash. The plant matching mode comprises the following steps: (1) mixing roegneria thoroldiana, snowfox crested wheatgrass, leymus and poa crymophila keng at the weight ratio of 2 to 2 to 2 to 3, so as to obtain a mixture applicable to an project slash of an alpine grassland region which takes ecological recovery as an aim; (2) mixing the roegneria thoroldiana, elymus nutans, puccinellia tenuiflora and puccinellia distans parl at the weight ratio of 3 to 1 to 2 to 2, so as to obtain a mixture applicable to the project slash of the alpine grassland region which takes the ecological recovery as the aim; and (3) mixing the elymus nutans, poa pratensis cv.Qinghai, the poa crymophila keng and festuca sinensis at the weight ratio of 3 to 2 to 2 to 1, so as to obtain a mixture applicable to a project slash of an alpine meadow which takes the ecological recovery as the aim. The plant matching mode provided by the invention is suitable for the plant matching mode of recovered series of a permafrost region, has extensionality and can be applied to plant recovery and reconstruction of project slashes with different types.

The invention relates to a method for cooling peripheral frozen earth and preventing water catchment in an excavation pit for a permafrost region. The method is characterized in that a pit slot is excavated at a position which is 0.5-5 m far away from the rim of the designed pit; the slot depth is a depth being 0-100 cm below underground permafrost table; a cooling pipe is paved at the bottom of the pit slot; a waterproof film is paved on the cooling pipe, the bottom of the slot, and the wall of the pit to a ground surface, and refilled and punned with filled earth; and the cooling pipe injected with circular freezing liquid is connected with a refrigerator on the ground surface through a hose. Shown by practices, with the adoption of the method provided by the invention, the problems of melting and stability loss of the frozen earth and the frozen earth in the excavation pit in a warms-season construction process and water leakage and water collection of underground water can be solved through the effective combination of refrigeration and water insulation, so that the permafrost stability can be effectively protected, and the normal construction and the long-term stability of the Qinghai-Tibet direct-current networking engineering in the permafrost region can be ensured.

The invention discloses a permafrost region highway distress prediction method based on an uncertainty cloud theory. According to the implementation process, (1) data is collected, and an original database is established; (2) evaluation parameters are selected, and initial concept division is performed; (3) parameter cloud model concept zooming is evaluated, and feature values are extracted; (4) highway distress concept division is performed, and feature values are extracted; (5) inference rules are determined, a quantitatively expressed inference rule parameter list is obtained, and a rule base is constructed; (6) a qualitative inference generator of a three-dimensional multi-rule cloud model of permafrost region highway distress is established; (7) a rule generation base antecedent is accessed, and the rule with the highest activation degree is found; and (8) a rule generation base consequent is activated, and the highway distress degree is output. Through the method, the cloud modeltheory is applied to permafrost region highway distress prediction, fuzziness and randomness are comprehensively considered, and the method has higher adaptability.

The invention discloses a method for manufacturing an X80-stage pipeline steel longitudinal submerged arc welding pipe. The method is used for manufacturing submerged arc welding pipes special for oil and gas conveying. The method comprises the steps that a hot-rolled steel plate with the microscopic structure being a proeutectoid ferrite+MA+granular bainite polyphase structure is utilized, and after processes of edge milling, pre-bending, JCO molding, pre-welding, finish welding and the like, the large-caliber, thick-wall and large-strain submerged arc welding pipe capable of being used for seismic zones, permafrost regions, landslide zones and other areas with deformation prone to happening is manufactured. The longitudinal submerged arc welding pipe manufactured through the method has the beneficial effects that the good mechanical property is achieved, the overall property of the welding pipe is uniform and stable, the geometric dimension is good, and the use requirements of steel pipes for seismic fracture zones, the permafrost regions and the landslide zones can be met.

The invention discloses a method for bored pile construction in a high-latitude and extremely-cold permafrost region. The method comprises steps as follows: (1) firstly, a field is leveled before construction, sundries in an operation area are cleaned, and the field is arranged; (2) guard barrels are buried, and sufficient wall protection mud or wall protection clay is prepared; (3) a measurement baseline and a base point are re-checked, and demarcated pile positions and the elevation are measured; (4) a drilling jig takes the position and is fixed; (5) a percussion drill is used for drilling and formation of holes, and the mud or the clay is poured into the holes for wall protection; (6) the depth of the percussion drill entering rock is controlled, and final hole identification is performed on the drilled holes; (7) the holes are cleaned, dregs are taken out, and the final hole diameter and depth are measured; (8) reinforcement cages are manufactured and mounted in final holes; (9) ducts for secondary hole cleaning are mounted in the final holes; (10) concrete is poured, and pile foundation inspection is performed. With the method, drilled hole walls are firm and stable; and equipment is simple in structure and is not limited by the field, the drilling efficiency can be significantly improved, and the construction cost can be saved.