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CN-122013805-A - Freezing-resistant construction method for photovoltaic foundation and bracket assembly in severe cold region

CN122013805ACN 122013805 ACN122013805 ACN 122013805ACN-122013805-A

Abstract

The invention belongs to the field of construction in severe cold regions, and in particular relates to an anti-freezing construction method for a photovoltaic foundation and a bracket component in the severe cold regions, which comprises the following steps of constructing an anti-freezing foundation; the method comprises the steps of taking a concrete pipe pile as a foundation, selecting the length of a pile body according to the characteristics of a frost heaving soil region, penetrating a seasonal frost soil layer to reach a stable bearing layer, carrying out auxiliary excavation and pile sinking on the frost soil, damaging the frost soil structure by adopting a hydraulic hammer matched with heating equipment, then using a rotary drilling rig to drill holes, carrying out construction on an anti-freezing cable trench, excavating a cable trench, paving an insulating layer and an impermeable film at the bottom of the trench, setting a drainage gradient, carrying out layered backfilling and tamping after laying a cold-resistant cable, carrying out installation on a low-temperature adaptive support and a component, selecting a low-temperature resistant photovoltaic component and the cold-resistant cable, fixing the support on the pipe pile foundation through a hoop device, carrying out non-welding grounding construction, carrying out grounding network laying by adopting an alloy cold-pressing connection process, and replacing the traditional welding process.

Inventors

  • Chang Zizheng
  • YU YUEWU
  • Jia Delu
  • QU SHUCHUN
  • GAO YAFEI
  • Chang Junmai

Assignees

  • 中建八局第二建设有限公司

Dates

Publication Date
20260512
Application Date
20260202

Claims (10)

  1. 1. The freezing-resistant construction method for the photovoltaic foundation and the bracket component in the severe cold region is characterized by comprising the following steps of: The construction method comprises the steps of constructing an anti-freeze thawing foundation, adopting a concrete pipe pile (3) as the foundation, selecting the length of a pile body according to the characteristics of a frost heaving soil region, penetrating a seasonal frozen soil layer (6) to reach a stable bearing layer, adding an anti-freeze agent and an air entraining agent into the foundation concrete, and curing by adopting an electric tracing method; The method comprises the steps of digging and pile sinking with assistance of frozen soil, adopting a hydraulic hammer to cooperate with heating equipment to destroy the frozen soil structure, then using a rotary drilling machine to drill holes, and immediately organizing a pile pressing machine to sink the pile after the holes are drilled; Step three, constructing an anti-freezing cable trench, excavating the cable trench, paving an insulating layer and an anti-seepage film at the bottom of the trench, setting a drainage gradient, and carrying out layered backfilling and tamping after laying the anti-freezing cable; The low-temperature adaptive support (2) is installed with the component (21), and is fixed on a tubular pile foundation through the anchor ear device (1), and an anti-wind connecting device is additionally arranged between the support (2) and the component (21); and fifthly, carrying out welding-free grounding construction, and adopting an alloy cold-pressing connection process to lay a grounding grid.
  2. 2. The freezing-resistant construction method for the photovoltaic foundation and the bracket component in the severe cold region is characterized in that in the first step, the depth of the concrete pipe pile (3) penetrating through a seasonal frozen soil layer (6) is at least 2m, the freezing resistance grade of the foundation concrete is not lower than F300, a 300mm thick broken stone cushion layer (5) and a 50mm thick extruded heat-insulating plate (4) are paved at the foundation from bottom to top, in the maintenance process of an electric tracing method, a phase-change energy-storage heat-insulating blanket is covered on the surface of the concrete, the constant temperature of the surface of the concrete is maintained by utilizing latent heat released by the phase-change material, the electric heating energy consumption is reduced, and microcracks caused by severe temperature fluctuation are prevented.
  3. 3. The freezing-resistant construction method for the photovoltaic foundation and the bracket assembly in the severe cold region is characterized by comprising the following specific process flows of crushing frozen soil by adopting a hydraulic hammer, heating the surface of a frozen soil layer by matching with a heating gun, leading holes by using a rotary drilling machine, leading the holes to penetrate the thickness of the frozen soil layer deeply, and immediately pressing piles after the holes are led, wherein the injection height of the freezing-resistant thixotropic slurry is 200mm lower than that of a natural ground, and a Fang Huitian-level sand and stone seal is arranged on the injection height, so that surface pollution caused by slurry overflow is prevented.
  4. 4. The freezing-resistant construction method for the photovoltaic foundation and the bracket assembly in the severe cold region is characterized in that in the third step, the construction specific parameters of the freezing-resistant cable trench are that the excavation depth is more than or equal to 1.2m, a polyurethane foam heat-insulating layer with the thickness of 100mm is paved at the bottom of the trench, drainage gradients of more than or equal to 3% are arranged at the bottom of the trench, impermeable films with the thickness of 1.5mm are paved at the two sides of the bottom of the trench, grading sand stones are filled in the trench after the cable is paved, 300mm thick soil is covered on the top of the trench, the trench is tamped in layers, and a ventilation drain valve is arranged in a backfill layer of the cable trench every 10m and used for draining condensed water generated by the ground temperature difference so as to prevent the cable from being frozen and extruded.
  5. 5. The freezing-resistant construction method for the photovoltaic foundation and the bracket component in the severe cold region is characterized in that in the fourth step, Q420-B steel is selected as a bracket (2), a low-temperature-resistant photovoltaic component (21) and a cold-resistant cable are selected as materials, angle steel is additionally arranged as an inclined strut, the bracket (2) is connected through bolts, a low-temperature torque compensation method is adopted when bolts are installed, a metal cold contraction coefficient table is consulted according to the ambient temperature of the construction day, fastening torque is corrected, low-temperature-resistant Wen Fangsong conductive paste is smeared at a bolt thread, the hoop device (1) is designed to be adjustable, the installation elevation of the component is adjusted when deviation occurs in the foundation position or elevation, and a low-temperature-resistant rubber damping pad is arranged on an inner side liner of the hoop device (1) and used for absorbing tiny displacement generated by the pipe pile and the bracket under different thermal expansion coefficients, so that stress concentration fracture at the hard connection position is prevented.
  6. 6. The freezing-resistant construction method for the photovoltaic foundation and support assemblies in the severe cold region is characterized in that in the fifth step, ACR alloy connectors (7) are adopted for connection between the assembly supports and the grounding grid, the ACR alloy connectors (7) are laid at the positions 2m around the box transformer substation through cold pressing, and vertical grounding poles penetrating into the position 2m below the frozen soil depth are arranged.
  7. 7. The freezing-resistant construction method for the photovoltaic foundation and the bracket component in the severe cold region is characterized by further comprising the steps of full-period monitoring and dynamic adjustment, wherein temperature sensors and displacement sensors are embedded in the bracket foundation and the bottom of a box transformer, a dynamic operation and maintenance model based on frost heaving data is built, and when the displacement sensor data are monitored to indicate that the foundation is unevenly settled or lifted by more than 3mm, the angle of the photovoltaic component is reversely compensated and adjusted through an adjustable hoop device on the bracket, so that the overall flatness of the photovoltaic component array is ensured.
  8. 8. The freezing-resistant construction method for the photovoltaic foundation and support assembly in the severe cold region according to claim 5, wherein the hoop device (1) comprises two arc plates (11), reinforcing ribs (12), fixing bolts (13) and base plates (14), wherein the reinforcing ribs (12) are arranged on the upper portion of one arc plate (11), the other arc plate (11) is connected with the arc plate (11) with the reinforcing ribs (12) through the base plates (14) and the fixing bolts (13), and the two arc plates (11) are clamped on the concrete pipe pile (3).
  9. 9. The freezing-resistant construction method for the photovoltaic foundation and support assembly in the severe cold region is characterized in that in the full period monitoring step, sensor detection data are transmitted and processed in the following mode, the temperature sensor and the displacement sensor are connected to a wireless data acquisition terminal arranged on site through a signal line, the wireless data acquisition terminal is in communication connection with a remote monitoring server through a mobile communication network, the acquired data packets are encrypted and uploaded, the detection data comprise hydrothermal migration parameters in frozen soil layers besides basic temperature and displacement, therefore, a soil humidity sensor and a pore water pressure gauge are additionally arranged in soil layers with different depths around the foundation, and the remote monitoring server calculates the unfrozen water content of the frozen soil layers according to uploaded soil moisture content change gradients and pore water pressure dissipation data so as to judge the latent period of occurrence of frost heaving.
  10. 10. The freezing-resistant construction method for the photovoltaic foundation and support assembly in the severe cold region is characterized by further comprising the steps of monitoring stress and posture of the foundation and support structure in a full period mode, presetting a fiber bragg grating strain sensor on a pile body reinforcement cage main rib of a prestressed high-strength concrete pipe pile, wherein the fiber bragg grating strain sensor is used for detecting axial tensile stress data and bending stress data of the pile body under the action of frost heaving force, installing an MEMS double-shaft inclination angle sensor on the top of a column of the photovoltaic support and used for detecting X-axis and Y-axis inclination angle data of the photovoltaic support relative to a horizontal plane, comparing the real-time tensile stress data with a preset concrete cracking resistance threshold value after the remote monitoring server receives the data, comparing the inclination angle data with a preset angle deviation threshold value, and automatically generating an alarm instruction containing fault pile number position information and sending the alarm instruction to a mobile terminal of operation and maintenance personnel when any data exceeds the threshold value.

Description

Freezing-resistant construction method for photovoltaic foundation and bracket assembly in severe cold region Technical Field The invention relates to the field of construction in severe cold regions, in particular to an anti-freezing construction method for a photovoltaic foundation and a bracket component in severe cold regions. Background Under the background of the global energy structure to clean transformation, centralized photovoltaic power generation becomes a key for renewable energy development due to scale advantages, but under special environments in severe cold areas, such as the lowest temperature of a region on a northly-opened dam can reach-35 ℃ and the depth of frozen soil can reach several meters, so that various difficulties are brought to on-site photovoltaic construction, the prior art has the defects that ① foundation construction defects that a traditional shallow foundation is easily influenced by frozen soil frost heaving to cause foundation lifting and damage, concrete is prolonged in setting time and slow in strength growth at low temperature, and lacks of targeted anti-freezing materials and maintenance measures, so that the foundation construction quality is difficult to guarantee. ② The frozen soil treatment defects are that the frozen soil is excavated by adopting conventional machinery, large frozen blocks are easy to generate, secondary freezing is easy to generate if a foundation is not constructed in time after excavation, and effective heat preservation and drainage measures are not adopted for cable trenches and pipeline trenches, so that structural damage is easy to be caused by freeze thawing circulation. ③ The equipment and material adaptation has the defects that a common photovoltaic module and a cable are easy to embrittle and lose efficacy at low temperature, the design of the support for resisting wind load and frost heaving is insufficient, wind and snow disasters are difficult to resist, the grounding construction adopts a traditional flat steel welding process, the welding quality is unstable in winter, and connection looseness is easy to occur. ④ The construction organization defects are that the construction period is staggered in peak mode without combining with the period of 'melting-freezing' of frozen soil, the winter construction is mostly in 'winter rest period', the construction period is serious, the construction period is delayed, the multi-major cooperation is insufficient, the working procedure is disordered, the frozen soil is not backfilled in time after being excavated, and the frost heaving risk is increased. Therefore, in order to solve the problems, the frost-resistant construction method for the photovoltaic foundation and the bracket component in the severe cold region is provided in a targeted manner. Disclosure of Invention The invention aims at the problems in the above, and specifically designs a freeze-proof construction method for a photovoltaic foundation and a bracket component in a severe cold region, provides a freeze-proof foundation design and construction scheme, ensures that the foundation penetrates through a frozen soil layer, improves the frost resistance and maintenance effect of concrete, and ensures the stability of the foundation. And the frozen soil excavation and protection process is optimized, the frozen soil excavation efficiency is improved, secondary freezing is avoided, and the damage of freezing and thawing circulation to the groove structure is reduced. And the support structure and the grounding process are optimized, and the low-temperature adaptability and the wind and snow resistance of equipment and materials are improved. The photovoltaic construction process flow in severe cold areas is optimized, peak staggering and multi-specialty cooperation in construction period are realized, the construction period is shortened, and the cost is reduced. In order to achieve the aim, the invention provides an anti-freezing construction method for a photovoltaic foundation and a bracket component in a severe cold region, which comprises the following steps: The construction method comprises the steps of constructing an anti-freeze thawing foundation, adopting concrete pipe piles as the foundation, selecting the length of a pile body according to the characteristics of a frost-swelling soil area, penetrating a seasonal frost soil layer to reach a stable bearing layer, adding an anti-freeze agent and an air entraining agent into the foundation concrete, and curing by adopting an electric tracing method; The method comprises the steps of digging and pile sinking with assistance of frozen soil, adopting a hydraulic hammer to cooperate with heating equipment to destroy the frozen soil structure, then using a rotary drilling machine to drill holes, and immediately organizing a pile pressing machine to sink the pile after the holes are drilled; Step three, constructing an anti-freezing cable trench, excavating the cable tr