Water Flow Pressure Research Articles

Numerical study on the interaction of high-pressure water injection with lead-bismuth in the SGTR accident of LFR

The lead-bismuth cooled fast reactor (LFR) is one of the fourth-generation advanced reactors, which has the advantages of enhanced safety and high efficiency. However, the steam generator tube rupture (SGTR) accident is an important design-based accident in safety analysis, which may cause a severe threat to the integrity of the reactor system. In this paper, a numerical method was established to simulate the interaction of high-pressure water injection with lead-bismuth, and validated against the LIFUS5 experiment. A sensitivity analysis of the effect of water and lead-bismuth parameters on the water flow rate, vapor generation, and pressure evolution was conducted. The results indicated that the vapor generation at the early time was mainly caused by the water flash evaporation, followed by an accelerated vapor generation rate due to the enhanced heat transfer resulting from the vapor bubble fragmentation and the direct contact of lead-bismuth with water. It was found that a significant temperature gradient existed at the vapor and lead-bismuth interface. There was a pressure spike at the impact of water injection to the lead-bismuth, followed by a continuous increase of the overall pressure and the final stable pressure in the lead-bismuth vessel exceeded the initial water injection pressure. Sensitivity analysis results indicated that, as the water injection pressure increased, the water flow rate, vapor mass, and pressure in the vessel increased significantly, but the temperatures of water and lead-bismuth had little influence on the interactions.

Hydroponic: A Study of Space Farming

This paper demonstrates the possibility of supporting human life in space, by growing fresh vegetables and producing them through simulated growing conditions. Supplying fresh vegetables to space stations and manned space missions is complicated and prohibitively expensive. Growing plants can be tough in space because of zero gravity, unavailability of soil, fertilizers, etc. Hydroponic is an advanced technology for growing plants without using natural resources (i.e. soil, air, natural fertilizers, etc.). It is a combination with greenhouses, it is advanced technology and highly intensive. The hydroponic technology takes place inside the enclosures to control air, temperature, and humidity using a vapor pressure deficit (vpd) controller, nutrient flow, and water flow controller. A major concern is the micro-gravity, which causes roots to grow differently than those from earth farming. In microgravity and hypo-gravity conditions, space farming utilizes a variety of methods like hydroponics, aeroponics, etc. This paper focuses on the hydroponics design, structure, operations, technique, substrate suitable for the plants, pH values, water level, and controllers required for hydroponic technology. The main objective of the paper is to build a preliminary design that is completely automatic that is robust and foolproof and find the definitive solution to the problems in the substrate and multi-spectrum lighting aroused due to gravity and vacuum conditions. The fully automated systems help to the reduction of labor and provide good healthy food to astronauts.

Design and Performance study of Francis turbine for high head applications.

Abstract Francis Turbines are widely employed globally for their adaptability and operational versatility across a broad range of water flow rates and pressure heads. This study explores the design and optimization of a Francis turbine configured for exceptionally high heads, specifically targeting a design head of 700 m. Traditionally, Pelton turbines are favoured for such high heads, but this study investigates the viability of Francis turbines in this range. Through comprehensive testing, including the development of hill chart diagrams to evaluate performance under various conditions, the study demonstrates promising efficiency levels. Utilizing a simplified approach, the design process involves empirical relations and the Khoj program, resulting in turbine designs representing three different speed numbers: 0.32, 0.42, and 0.52. Efficiency and sediment erosion rates were computed for each and compared between the three designs. The comparison indicates that while the turbine with a speed number of 0.32 exhibits lower efficiency, it offers superior erosion resistivity. Conversely, turbines with speed numbers 0.42 or 0.52 show better efficiency, especially in handling fluctuations in operating conditions. The findings suggest a balance between efficiency and erosion resistivity, recommending the turbine designed for a speed number of 0.32 for superior erosion resistance, and the turbine with a speed number of 0.42 for greater efficiency and operational range. This study broadens the horizon for Francis turbines in high-head applications, offering insights into their potential and viability in extreme conditions.

Określenie zmian ciśnienia podczas wiercenia otworu z półzanurzalnej platformy wiertniczej

The article states that a ship in the open sea is in a complex oscillatory motion due to the aerodynamic force of water flow and hydrodynamic pressure. Among the lateral, keel, horizontal, and vertical vibrations, only the vertical vibration of the vessel primarily affects the technological process of drilling a well. The article determines the magnitude of the hydrodynamic pressure that arises in the wellbore from the oscillation of the semi-submersible drilling platform in the absence of well flushing and a telescopic string, a compensator for vertical movement. When formulating the problem accurately, one should take into account the presence of natural vibrations of both the drilling tool and the semi-submersible drilling platform from which the well is to be drilled. The semi-submersible drilling platform was awarded by Caspian Drilling Company to two subsidiaries of Keppel offshore & Marine Company with Caspian Rigbuilders and Caspian Shipyard Company. This platform, named after Heydar Aliyev, is the first and the only drilling platform in the world with a 1,400-atmosphere system technology. Its carrying capacity is 5,600 tons, and its displacement is 47,500 tons. Vertical vibrations of the semi-submersible platform, caused by hydrometeorological conditions, set in motion the drilling tool associated with the semi-submersible drilling platform, along with the flushing solution that fills the well during drilling without a riser. This leads to a change in the hydrodynamic pressure in the well. Therefore, the change in hydrodynamic pressure in the well must be checked using a special installation that simulates the vibrations of the vessel and drilling tool in a well filled with drilling fluid.

Pressure retarded osmosis enhanced by micro-nano bubbles: Coupling effects of operation conditions and mass transfer resistance analyses

The concentration polarization is one of the bottlenecks of pressure retarded osmosis (PRO) for industrial-scale application. Micro-nano bubbles (MNBs) could form a strong repulsion and shear force on the membrane surface, thus, the degree of concentration polarization is reduced, and hence, both the water flux and power density could be increased. In this paper, the synergistic effects of MNBs with concentration, temperature, water and air flow rates, pressure, and spacers were investigated through membrane cell scale experiments. A numerical model with trans-membrane heat flux and MNBs effects is built and validated by the experiment results. The mechanism of strengthening effect of MNBs could be explained. A maximum promotion of 6.28 % was achieved for concentration combination of 0.171–1 mol/L. However, the promotion ratio of water flux was deceased significantly with higher temperature (<1 % for 45 °C) and higher pressure (nearly zero for 7 bar). The light MNBs would be pushed away from membrane under larger water flux with larger osmotic pressure difference. The variations of mass transfer resistances, and the thicknesses of boundary layers were discussed. Moreover, the key variables that have significant impacts on the metrics of PRO process were identified through partial least squares analysis.

Geomorphological and morphometric characterization of subglacial channels on Devon Island, Nunavut, Canada

Subglacial channels are morphologically and morphometrically distinct in comparison to fluvial channels, yet their identification from remote sensing data is still problematic. To contribute to the current set of criteria used to identify such channels, we performed a detailed analysis of two subglacial channel networks on Devon Island, Nunavut, Canada. In planform, these channels are isolated, finger-like networks that drain into a main stem and have distinct cross-sectional and longitudinal profiles. Cross-sections are flat-bottomed with steep walls and longitudinal profiles are convex and exhibit undulations, typical of pressurized water flow (i.e., subglacial flow). To facilitate remote sensing identification, we interrogated how well-known scaling relationships capturing hydraulics and mass balance dynamics of fluvial systems differ in subglacial channels. Scaling relationships typically used to discern connections between discharge and channel and catchment size in fluvial systems were applied to both networks, yielding trends distinct from the fluvial literature. We suggest that the weakly correlated relationship we found between channel discharge and the size of the drainage area indicates a discrete point or line source of water, such as a moulin or crevasse.

Chemical improvement of soluble rocks: Foundation of Mosul Dam as case study

The dissolution of soluble rocks (gypsum/anhydrite) beneath the Mosul Dam by water seepage has been observed upon the initial impoundment; consequently, several sinkholes have been manifested in the vicinity of the dam site. Traditional grouting has been envisaged as a potential remedy; however this measure has not eradicated the problem. The main purpose of this study is to overcome the solubility of the gypsum/anhydrite rocks using chemical grouts. Rock samples were acquired from the Fatha Formation outcrop and problematic layers of brecciated gypsum situated at varying depths beneath the Mosul Dam. Two commercially available liquid polymers, polyurethane (PU) and a mixture of acrylic and cement (ARC) were used to investigate their sealing performance in halting of the solubility of the rocks (gypsum/anhydrite). To simulate the dissolution phenomenon under the influence of artificial hydraulic pressure of the dam and the water flow in its abutments, two distinct laboratory models were devised. The outcomes from the experimental study on both untreated and treated samples revealed that the acrylic-cement composite (ARC) and polyurethane (PU) are influential polymers in halting the solubility of the gypsum rock samples under both factors of water pressure and high-velocity water flow.

Repair of undersea concrete using biopolymer-assisted plant urease

Concrete repair in marine environments is influenced by various factors, particularly underwater pressure and dynamic water flow. Traditional materials used for underwater concrete repair suffer from issues such as dilution, dispersion, susceptibility to erosion by moving water, and poor grout retention. In this study, a novel biopolymer-based undersea crack repair material composed of quaternized chitosan (Hydroxypropyl trimethyl ammonium chloride chitosan, HACC), sodium alginate (SA), urease, and aggregates was developed. It investigated the impact of biopolymers on urease's physiological and biochemical properties, as well as its mineralization capacity. Additionally, It conducted a comprehensive evaluation of the fluidity, rheological behavior, grout retention, mechanical properties, and anti-permeability rate of the bio-grouting material. The results showed that the optimized bio-grouting material exhibited suitable viscosity and fluidity. After injection, it rapidly formed a cohesive seal, with a grout retention rate exceeding 90 % at 48 days. The water resistance of the repaired concrete reached 93 %. Microstructural analysis using X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and scanning electron microscopy (SEM) revealed strong electrostatic interactions between HACC and SA molecular chains. These interactions encapsulated mineralization products and sand particles, resulting in a denser microstructure.

105 Water quality analysis and flow rate comparison between wean-finish swine barns

Abstract Water is an essential nutrient to sustain life and a vital component of biological functioning, impacting regulation of pig body temperature along with transporting nutrients to the body. Drinker availability, position, design, water flow rate and pressure, and water quality are major components of pig water intake. The ideal water flow rate for wean-to-finish pigs is 1 L m-1. Excessive flow rates could limit pig water intake and increase humidity in the barn, while too little water flow can lead to a decrease in water intake and biological functioning of the pig. Water should not contain harmful substances and should be readily accessible to pigs. Compounds in water are highly variable depending on region, water source, and pH. Quality of water influences feed consumption along with pig health. Water can contain a variety of microorganisms such as bacteria, viruses, algae, and protozoa; while not all microorganisms are harmful a highly contaminated water analysis is an index of poor water quality. In this study water quality and water flow rates were analyzed across five wean-finish sites comprising 16 barns for three turns of finishing pigs. Water flow rates were measured twice per turn, wk 1 and wk 17. Each barn contained 36 pens and flow rate measurements were collected in 8 pens evenly distributed within the barn. One suspended water source was available per pen, with two nipple drinkers per water source. Water flow rates were averaged over each turn within barns. Average water flow rates were 1.42 L m-1 with standard deviation of 0.44 L m-1. Overall barn water flow rates ranged from 0.78 to 2.19 L m-1. Barn flow rates were compared over time to evaluate performance and maintenance of facilities. Water quality samples were also collected and submitted for standard water analysis. Results will provide information on management strategies to assess water quality and water flow rates in wean-finish facilities.

Prevention of Water Seepage Impact on the Soluble Rocks Using Colloidal Silica

Water seepage flow can dissolve soluble minerals that exist in rock formations. With the development of the excavated area due to dissolution, the water seepage velocity (discharge) into the dissolved rock will also increase. Therefore, water seepage and dissolution propagation are two interrelated processes. Mosul Dam foundation has experienced these processes since its construction, resulting in karstification in the reservoir and foundation of the dam. The present seepage-dissolution measure to minimize this phenomenon relies on traditional cementitious grouts. However, this measure has not been able to address the issue effectively. Currently, there are a few studies on the chemical remediation of soluble rocks under the influence of high-velocity water flow and water pressure. Therefore, the first part of the current study focuses on the impact of high-velocity water flow and water pressure on the dissolution acceleration of gypsum/anhydrite rocks. In the second part, the waterproof capacity of silica colloidal and its impact on the solubility reduction of the rocks is evaluated. Two distinct laboratory models were designed to simulate rock dissolution in the dam abutments and under the dam. Two sets of experiments were conducted on untreated and silica-treated samples. The experiments were executed on the samples extracted from Fatha Formation outcrop and problematic layers of brecciated gypsum situated at varying depths of the Mosul Dam foundation. The obtained findings reveal that the colloidal silica grout markedly prevents the water seepage impact on the soluble rock and that it can be very useful as an alternative to cement-based grouts.

Experimental investigation on flow patterns and pressure gradients of shale oil–water flow in a horizontal pipe

With the growing demand for hydrocarbon resources and the depletion of conventional oil and gas reservoirs, the development of shale oil will become popular. As the shale oil fields gradually enter the middle and late stages of exploitation, the water content reaches as high as 60–80 %. Analyzing the flow characteristics of shale oi–water flow during high water content can help optimize the range of flow parameters and improve pipeline transportation efficiency. However, research on shale oil–water flow patterns and pressure drop prediction models is still lacking. Therefore, this work conducted shale oil–water flow experiments in the multi-test section pipe flow loop, considering the temperatures (40–70 °C), mixture velocity (0.2–1.2 m/s), and water contents (60–80 %). The flow patterns of shale oil–water flow are studied, and the flow pattern maps are created. Moreover, the influence factors on pressure gradient are analyzed, including pipe diameter, water content, mixture velocity, and temperature. Eventually, the pressure drop prediction models are modified based on the pressure gradient and holdup experimental data. The results show that a thin oil film and an oil-sticking layer are adhered to the pipe wall at 40 °C and 50 °C, respectively. The mixture velocity increased from 0.4 m/s to 1.2 m/s, and the pressure gradient increased by 69.89 % when the temperature and water content are constant. The lubrication coefficient is introduced in stratified flow (ST) and three-phase stratified flow (TPS) models, and the pipe flow friction coefficient is modified in dispersed flow (DF) and intermittent flow (IF) models. Moreover, the average relative deviations between experimental data and calculated values of ST, TPS, DF, and IF modified models are 4.49 %, 4.23 %, 4.40 % and 5.17 %, respectively. Therefore, surface wettability reduces the friction between the oil phase and the pipe wall, and the oil film and oil-sticking layer increase the pipe flow resistance.

Degradation Behavior and Lifetime Prediction of Polyurea Anti-Seepage Coating for Concrete Lining in Water Conveyance Tunnels.

In the lining of water conveyance tunnels, the expansion joint is susceptible to leakage issues, significantly impacting the long-term safety of tunnel operations. Polyurea is a type of protective coating commonly used on concrete surfaces, offering multiple advantages such as resistance to seepage, erosion, and wear. Polyurea coatings are applied by spraying them onto the surfaces of concrete linings in water conveyance tunnels to seal the expansion joint. These coatings endure prolonged exposure to environmental elements such as water flow erosion, internal and external water pressure, and temperature variations. However, the mechanism of polyurea coating's long-term leakage prevention failure in tunnel operations remains unclear. This study is a field investigation to assess the anti-seepage performance of polyurea coating in a water conveyance tunnel project located in Henan Province, China. The testing apparatus can replicate the anti-seepage conditions experienced in water conveyance tunnels. An indoor accelerated aging test plan was formulated to investigate the degradation regular pattern of the cohesive strength between polyurea coating and concrete substrates. This study specifically examines the combined impacts of temperature, water flow, and water pressure on the performance of cohesive strength. The cohesive strength serves as the metric for predicting the service lifetime based on laboratory aging test data. This analysis aims to evaluate the polyurea coating's cohesive strength on the tunnel lining surface after five years of operation.

Leakage and loss of contact/adjustment effects on slip-joins of a jet-pump assembly of BWR nuclear reactors by dynamic fluid-structure interaction modelling

This work presents a methodology for the evaluation of self-excited vibrations of jet-pump assemblies that make up the water recirculation system of boiling water nuclear reactors. Therefore, for the analysis three different type of models were developed: finite element, computational fluid dynamics and fluid-structure interaction models of a jet-pump assembly. The models were subjected to pressurized water flow in order to analyse leakage effect in the gaps between slip-joints and the diffuser of the assembly, and how the vibrations level can affect the integrity of jet-pump assemblies were also evaluated. Analyses of loss of adjustment of structural components in the wedge system were also performed, in order to study their contribution on the vibrations level under water flow conditions, since this effect has been identified as a potential failure mechanism in jet-pump assemblies. Three different gap sizes were modelled along with two critical loss of mechanical/adjustment components conditions, and the vibrations level of the jet-pump assembly under each modelled condition was obtained. The results showed the presence of self-excited vibrations of the jet-pump assembly under water flow, however little effect of leakage occurred in the slip-joint, on the vibration levels of the jet-pump assembly. Nonetheless, for the cases of loss of adjustment/contact components in the wedge system, high natural frequencies were obtained, and the vibrations were more severe when the loss of adjustment occurred in two mechanical/adjustment components. The results were also used to identify the mechanical components that may experience accelerated material degradation in the mixing-diffuser section of jet-pump assemblies, which occurred under loss of adjustment of mechanical components.

Performance investigation of poly(vinylidene fluoride-cohexafluoropropylene) membranes containing SiO2 nanoparticles in a newly designed single vacuum membrane distillation system.

The current study focuses on the development of a superhydrophobic poly(vinylidene fluoride-cohexafluoropropylene) nanocomposite membrane suitable for vacuum membrane distillation by incorporating SiO2 nanoparticles. At loading hydrophobic nano-SiO2 particle concentration (0.50-1.50 wt.%), the developed nanocomposite membranes are optimized in terms of vacuum membrane distillation performance. The influence of temperature, vacuum pressure, and feed water flow is studied for desalinating high-salinity brine. The results show that the developed vacuum distillation membrane is capable of 95% salt rejection during the treatment of a highly saline feed (65,000 ppm) at fixed flow rates of 120L/h saline feed and different operating conditions consisting of feed inlet temperatures ranging from 40°C to 70°C and distillate inlet temperatures of 7-15°C. The vacuum membrane distillation process achieves 0.38-1.66% water recovery with increasing concentration factor, meaning that recovery is increased, and shows a specific electrical energy consumption of 5.16-23.90 kWh/m3 for product water. Overall, the newly designed membrane demonstrates suitability for a vacuum membrane distillation system. PRACTITIONER POINTS: Desalinate high-salinity brine (TDS > 35,000 ppm) using a vacuum membrane distillation system. A hydrophobic PVDF-HFP/SiO2 nanocomposite membrane development for vacuum membrane distillation. A newly designed single vacuum membrane distillation system for RO brine treatment.

Reducing reactive energy consumption by optimizing operating modes of irrigation pumping stations

The article develops energy and resource efficiency modes of the technological process that meet the requirements of the “frequency converter - asynchronous motor - pump - pressure pipeline” system as a control object. Methods for regulating water pressure and water flow produced by pumping units are considered in order to ensure a schedule for water supply to irrigation pumping stations. The active, reactive and total electrical energies received by an asynchronous motor to change water flow by changing the position of the pressure valve in the pressure pipeline are calculated. In order to optimize water flow and water pressure by changing the speed of rotation of the pump impeller, the frequency converter system of an asynchronous motor with a squirrel-cage rotor was calculated and compared with the method of changing water flow using a push valve, by calculating active, reactive and total electrical energy from the network.

Gel-forming composition to increase the efficiency of water isolation in horizontal wells

Relevance. The need to develop new technical and technological solutions to improve the efficiency of water isolation in wells with horizontal termination in reservoirs with layered heterogeneity of the formation. Aim. To identify and propose a promising gel-forming composition for conducting water isolation in wells with horizontal termination in reservoirs with layered heterogeneity of the formation. Object. A well with a horizontal termination in reservoirs with layered heterogeneity of the formation. Methods. Laboratory and bench studies of the gel-forming composition for isolating water inflow in wells with different reservoir permeability by modifying it with functional additives and further adapting its application to various mining and geological conditions of the well; technology of injection of compositions with different viscosity in wells with horizontal termination in reservoirs with layered heterogeneity of the formation. Results. The paper considers the theoretical aspects of a hydrophobic layer formation on a watered reservoir surface effected by a hydrophobic composition, when it enters the reservoir. The paper introduces the mechanism of a water-insulating screen formation during injection of a gel-forming composition. The authors have defined the basic requirements for the gel-forming composition. They developed the formulation of the gel-forming composition with a different gelation time from 1 to 8 hours. Due to the composition injection, a water insulation screen is formed that can withstand significant water flow pressure. The water breakthrough pressure varies and depends on the initial permeability: with an increase in gas permeability from 0.1 to 1 mm2 of the breakthrough pressure it decreases by water and ranges from 4.5 to 11.5 MPa/m.

Two-Dimensional Simulation of Dam Break with Partial Damage Condition using Ansys Software

The issue of dam failure has been a key contributor to massive catastrophes, as well as economic and physical destruction. Nevertheless, the effectiveness and accuracy of the simulation of a dam break model are still under debate. In this study, a simulation of a 2D model of the dam breaking half-filled water tank was carried out using Ansys software to evaluate the deformation and water pressure of dam break flow. Four sensors were installed to examine the changes in pressure of the water deformation. Deformation of water at a certain time of the dam break simulation and the pressure of water inside were analyzed and compared with the experimental result, which has been reported by Lobovský. Validation and verification of hydrostatic tests have been found to be in agreement with the current model simulation. An extensive set of data for the simulation is given access as supplementary materials for the direct result of the recent initiative. The results show that by excluding minor differences in wave shape and duration of water movement, the deformation of water exemplifies the same behavior as the experimental results. For experimental data, the non-dimensional time of the dam break event is ranged within 0 to 7.14828 ms while the pressure of water flow is within 0 to 3.0441 Pa. As for simulation results, the non-dimensional time of the dam break event is ranged within 0 to 202 ms whereas the pressure of water flow is within 0 to 0.54124 Pa. Thus, to strengthen the quality numerical model, future work should emphasize the initiative to incorporate the Smooth Particle Hydrodynamics (SPH) method with the goal of improving computational validity and efficiency.

Development of a rapid heat cycle injection molding system using infrared radiation and convection heating and influence on morphology and mechanical properties

Conventional injection molding is widely used to produce plastic parts, mainly in the automotive industry, due to the high production ratios and quality of injection parts. Low mold temperatures are usually employed to decrease cycle molding time and final process costs; however, resulting surface defects include weld lines, sink marks, and warpage. Therefore, plastic parts are often subjected to secondary processes to reduce the surface defects. A dynamic mold heating and cooling control technology, rapid heat cycle molding (RHCM), was employed to optimize the injection molding process. The present study combined convection heating (pressurized water flow) and external infrared heating systems to investigate the effect of dynamic temperature control on the injection molding process. The infrared heating system was custom built to allow studying under controlled conditions the influence of several process parameters on the resulting morphology and mechanical properties. Results show significant gains from using the RHCM technology to optimize the conventional process, namely, at 100 °C no frozen layer is formed while simultaneously increasing the Young’s modulus. Industrial companies struggling with defects resulting from the thermal changes during injection molding can thus consider RHCM as a mitigation strategy and use these results as a guide for tool design and implementation of the technique.

Investigation on the pore water pressure in steel bridge deck pavement under the coupling effect of water and vehicle load

The water damage is a severe problem existing steel bridge deck pavement (SBDP) and still has not been fully studied. To investigate the pore water pressure of SBDP under the coupling effect of water and vehicle load, some typical permeability characterization parameters are selected firstly. Then, the water permeability simulation model under the most unfavorable vehicle load is established. Next, the spatial distribution of pore water pressure in different area of SBDP is analyzed and compared. Lastly, the process of water flow and pore water pressure changes are discussed. Results show that the simulation results are consistent with the characteristics of water permeability phenomenon during practical vehicle travel. The process of water flow and pore water pressure changes is corresponding to the pumping phenomenon in the engineering practice. This positive and negative cycle of pore water pressure could lead to spalling between asphalt and aggregate, which would accelerate the appearance and development of SBDP distress. This paper clarifies the permeability characteristics and pore water pressure change in SBDP. The findings are important for the design, construction and maintenance of SBDP to mitigate or avoid water damage.

MODELING OF PORE WATER PRESSURE IN FREEZING DISPERSED SOILS DURING MOISTURE MIGRATION

Frost heaving of soils is the main cause of engineering accidents in cold regions, but the current experimental as well as numerical studies focus on frost heaving deformation of soils, while there are fewer numerical studies on the main factors causing frost heaving deformation: pore water pressure. In this study, new calculation formulas of pore water pressure for saturated frozen soil are obtained by solving Gibbs free energy equation, and a thermo-hydraulic coupling model under different boundary conditions is constructed to calculate the pore water pressure values and water flow during water migration process. The results showed: (1) the pore water pressure of freezing soil with the ice lens is about ten times that without the ice lens, and the calculated results agree with the previous known experimental results; (2) The temperature of the cold end directly determines the upper limit of the pore water pressure value of freezing soil; (3) Pore water pressure decreases with depth much faster than the rate of temperature decrease.