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To investigate the influence of the filling thickness and internal water pressure on the stability of a water supply pipeline, a typical pipeline section of the Sun Mountain Water Supply Project is selected as the research object. A numerical simulation method is adopted to establish a three-dimensional finite element model integrating a “double-line pipeline-artificial fill-foundation” to study the influence of different single-layer filling thicknesses and internal water pressures on the mechanical properties of the double-line pipeline. The results of the study show that the relative error between the intrinsic mode of the finite element model of the double-line pipeline and the frequency identified by the dispersion entropy variational mode decomposition (DVMD) method on the measured vibration signals is only 1.55%, which confirms the validity of the finite element model and the accuracy of the results. With increasing soil filling and increasing single-layer filling thickness, the vertical displacement of the double-line pipe gradually increases, with a maximum value of 12.24 mm. With increasing single-layer filling thickness, the rate of increase in the vertical displacement of the double-line pipe increases. With increasing soil filling, the tensile and compressive stresses on the double-line pipe increase gradually, with maximum values of 0.148 MPa and 0.568 MPa, respectively. When the number of cycles is the same, the tensile and compressive stresses of the pipe sheet increase with increasing single-layer filling thickness. When the internal water pressure is 0.6 MPa, the trends of the inner and outer circumferential deformation and tensile and compressive stresses of the left and right lines of the pipes are basically the same. The outer stresses are lower than the inner stresses, among which the tensile stresses are reduced by 25% and 20.1%, and the compressive stresses are reduced by 16% and 18.2%, respectively. Under the joint action of the earth pressure and internal water pressure, the deformation of the double-line pipeline and the compressive stress tended to decrease and then increase, and the tensile stress gradually increased. The research results provide a theoretical reference and basis for similar water supply pipeline projects.

Permeable pavements mitigate the impacts of urbanization on surface waters through pollutant load reduction, both by sequestration of pollutants and stormwater volume reduction through exfiltration. This study examined the non-winter water quality performance of two side-by-side permeable pavements in the Ohio snowbelt. The permeable interlocking concrete pavements were designed to drain impervious catchments 2.2 (large) and 7.2 (small) times larger than their surface area, were located over clay soils, and incorporated the internal water storage design feature. Nutrient reduction was similar to past studies—organic nitrogen and particulate phosphorus were removed through filtration and settling, while dissolved constituents received little treatment. Because of 16 and 32 % volume reductions in the small and large installations, respectively, nutrient loads were often significantly reduced but generally by less than 50 %. Aluminum, calcium, iron, magnesium, lead, chloride, and total suspended solids (TSS) concentrations and loads often increased after passing through the permeable pavements; effluent TSS loads were three- to five-fold higher than influent TSS loads. This was apparently due to seasonal release of clay- and silt-sized particles from the soils underlying the permeable pavement and inversely related to elapsed time since winter. The application of de-icing salt is thought to have caused deflocculation of the underlying soils, allowing particulates to exit with stormwater as it discharged from the underdrain of the permeable pavements. By autumn, both permeable pavements discharged metals and TSS concentrations similar to others in the literature, suggesting the de-icing effects lasted 3–6 months post-winter. Sodium may substantially affect the performance of permeable pavements following winter de-icing salt application, particularly when 2:1 clay minerals, such as vermiculites and smectites, predominate.

Water resources are increasingly scarce, and in drought prone production systems, the capability of the plant to recover its adverse effects is important for yield stability. There is an urgent need to develop water-saving strategies for wheat production. Water stress at critical growth stages diminishes wheat production and has harmful effects on crop growth and development; however, regulated water deficit and potassium foliar application ameliorates its adverse effect up to a certain extent. Consequently, the water deficit effect at different growth stages of the crop with exogenous application of potassium was evaluated in a screenhouse experiment in a complete randomized design (CRD) having four repeats. Varieties of wheat, i.e. Lalma (drought resistant) and Pakhtunkhwa-2015 (drought susceptible), were sown. Water deficit, i.e. mild water stress (50% of water required for field capacity) and severe stress (no application of water), at different growth stages of the crop were imposed. Potassium (K) foliar spray (1%) from potassium sulfate (K2SO4) was applied at the respective stage subjected to water deficit levels. Internal water status, i.e. relative water content (RWC) and water retention capacity (WRC), were attained maximum at tillering stage under mild stress than the rest of the stages with maximum for Lalma. Conversely, water saturation deficit (WSD) and water uptake capacity (WUC) were higher under severe stress imposed at grain filling stage. Theses indices were maintained by foliar potassium application. Similarly, dry matter (DM) allocation varied for stress level imposition and translocation to other parts were improved under foliar K application. The chlorophyll indices, i.e., soil plant analysis development (SPAD) value, also decreased with the severity of water deficit. Grain yield was higher under stress imposition at grain filling stage than the rest of the stages, though severe water stress decreased yield significantly. The Potassium (K) foliar spray showed no prominent effect at grain filling. Canopy temperature increased with stress severity and was maintained under K foliar spray. Osmotic adjustment, water and turgor potential were affected by water stress and maintained with foliar K spray. Grain quality and biochemical traits of wheat were affected severely under water deficit. Potassium foliar spray was found to decrease the adverse effect of the water stress and hence maintained the quality and biochemical characters. It is concluded that application of foliar potassium decreases the adverse effects of water stress at any growth stage, minimises the stress indices drastic effect and maintains the internal water balance of the crop at different stages subjected to water deficit.

Deep-buried soft soil water conveyance tunnels traversing multiple geological layers are susceptible to structural damage under dynamic internal water pressure. The cross-layer stratum is particularly sensitive to adverse conditions, such as dynamic internal water pressure and high external water loads. Using the pressurized water conveyance tunnel from the Central Yunnan Water Diversion Project as a case study, numerical analysis of tunnel lining segments under dynamic internal water pressure was conducted using the finite element method (FEM). The mechanical behavior and stress distribution of the lining segments under different water conveyance schemes—including empty, semi-filled, and filled cases—were systematically analyzed in terms of lining stress, deformation, longitudinal and circumferential displacements, and bolt stress. The results indicate that the lining segments experience the maximum external water pressure under an empty case, with the transverse and longitudinal stresses of the lining bolt identified as a critical weak position. As water transitions from an empty to a semifilled status, horizontal expansion deformation of the lining decreases, stress distribution becomes more uniform, and stress concentrations are observed in the vault region. Further transitioning to a filled status leads to a gradual balance between internal and external pressures, resulting in convergent structural deformation. Moreover, the largest lining deformations occur in cross-layer stratum where the tunnel passes through soft-hard soil layers. Additionally, the assembly angle of the lining segments significantly influences the structural stress. As a result, both geological conditions and segment assembly angles should be considered during tunnel design to optimize performance.

This study investigated the bearing capacity and failure characteristics of a shield tunnel lining structure subjected to top overload and simultaneous unloading on both sides of a tunnel, considering the presence of internal water pressure. The results show that the structural response of the shield tunnel lining is most unfavourable under the condition of a fully filled pipe, where the internal water pressure reduces the axial force of the lining ring section, compared with the conditions of an empty pipe and a partially filled pipe. When the internal water pressure increases from 0 MPa to 0.6 MPa, the convergence deformation of the lining ring under a top overload of 400 kPa increases by 23.6%, resulting from a reduction of 27.2% in the maximum axial force at the lining section. Similarly, the convergence deformation of the lining ring under simultaneous unloading of 400 kPa on both sides of the tunnel increases by 21.6% because of a reduction of 56.4% in the maximum axial force at the lining section. The shield tunnel lining rings under the action of internal water pressure when subjected to top overload or simultaneous unloading on both sides of the tunnel exhibit the same failure characteristics. As the overload or unloading value increases, the lining ring deformation gradually increases, the joint opening exceeds the waterproof design limit, and the bolt enters a plastic yield state as its stress exceeds the yield strength. Cracks occur in the concrete at the positions of the lining segments, segmental joints, and handholes because of the large strain values. Moreover, the stress of the steel bars, joint panels, and anchor bars inside the lining segments may exceed their yield strength. During the top overload, the bending moment and axial force of the lining ring section increase, whereas when unloading on both sides of the tunnel, the bending moment increases and the axial force decreases. Compared with the case with an overload value of 400 kPa, the maximum positive and negative bending moments of the lining ring under a lateral unloading value of 400 kPa decrease by 11.5% and 14.4%, respectively, whereas the maximum axial force decreases by 73.1%. This considerable decrease in axial force during lateral unloading leads to greater section eccentricity and a more adverse structural response of the lining structure than does top overload. Therefore, during the operation of shield tunnels with internal water pressure, the influence of unloading on both sides of the lining structure caused by soil stress relaxation should be taken seriously.

Forecasting supply and demand is fundamental to the sustainability of the water system. Demand for urban water seems on an ever-upward trajectory, with use increasing twice as quickly as population throughout the 20th century. However, data from Ballarat, a city in south-eastern Australia, show that despite this conventionally held wisdom, total water usage actually peaked over 30 years ago. While the 1997–2009 ‘Millennium Drought’ had some effect, the decline commenced many years before. Initially, this was due to a reduction in external domestic water use, which correlates well with an increase in water price. However, the effect was found to not be purely economic as the price was not volumetric-based. Internal water use seems more affected by technological advances and regulatory controls. Interestingly, there was no relationship found between rainfall and water demand. The role of price, water-reduction education programmes, water-efficient technology and regulation supports previous research that a multifaceted approach is required when developing demand-reduction policies and strategies. This finding emphasises the importance of understanding the component of consumptive behaviour being targeted, and ensuring that policies being implemented are appropriate for the desired behavioural change.

High-strength concrete generates a significant amount of heat during curing, which can cause delayed ettringite formation and early thermal cracking. Such problems are particularly acute in Hong Kong because of the local practice of designing concrete mixes to have rather high cementitious contents to avoid non-compliance with the stringent strength requirements. Moreover, in Hong Kong, there is still a lack of clear specifications of the temperature control limits to be imposed. Hence, the temperature control of curing high-strength concrete in massive columns/walls has, up to now, remained guess work. In this paper, temperature control limits are proposed, and a case study on temperature control of massive C80 concrete columns during curing is presented. Due to the high cementitious content and large column size, an internal water-cooling system, designed with the help of thermal analysis by the finite element method, was installed. In this system, each pipe was a double-pipe for both water inflow and outflow. It had successfully avoided exceedance of temperature control limits and formation of early thermal cracks. The lessons learned, as summarized in the Conclusions, should be useful for the optimum design of temperature control regimes for massive high-strength concrete members.

In practical applications, the safe operation of large-diameter prestressed concrete cylinder pipes (PCCPs) depends on the loading performance under internal water pressure. However, there is lack of damage tests for the full-scale large-diameter PCCPs due to economic cost and experimental difficulty. In this paper, a full-scale PCCP with diameter of 3.2 m was tested to verify the bearing capacity for applying to an actual water transfer project. The PCCP was designed by the limit state method and manufactured in a prefabrication plant. During the test, the strains of concrete, prestressed steel wire, and mortar were detected to evaluate the limit state of bearing capacity under internal water pressure. Based on the test results and the strain analysis at the limit state, it was found that when the water pressure reached 1.9 MPa, the concrete outside the steel cylinder was at the serviceability limit state, and the prestressed steel wire was in elastic, while some protective mortar exceeded the serviceability limit state due to the appearance of visible cracks. A good accuracy of the theoretical calculation with the predicted results lower about 9.4% and 8% than tested pressures at decompression and cracking states. Moreover, the cracking pressure of concrete and bursting pressure of pipe were 2.5 and 6 times of the working pressure according to the calculation results. This indicated that the PCCP used in this study had sufficient safety in actual operation. However, it should be noted that the tensile control strain of mortar may be overestimated by the current code.

Interfacial solar vapor generation is a promising technique to efficiently get fresh water from seawater or effluent. However, for the traditional static evaporation models, further performance improvement has encountered bottlenecks due to the lack of dynamic management and self-regulation on the evolving water movement and phase change in the evaporation process. Here, a reconfigurable and magnetically responsive evaporator with conic arrays is developed through the controllable and reversible assembly of graphene wrapped Fe 3 O 4 nanoparticles. Different from the traditional structure-rigid evaporation architecture, the deformable and dynamic assemblies could reconfigure themselves both at macroscopic and microscopic scales in response to the variable magnetic field. Thus, the internal water transportation and external vapor diffusion are greatly promoted simultaneously, leading to a 23% higher evaporation rate than that of static counterparts. Further, well-designed hierarchical assembly and dynamic evaporation system can boost the evaporation rate to a record high level of 5.9 kg m −2 h −1 . This proof-of-concept work demonstrates a new direction for development of high performance water evaporation system with the ability of dynamic reconfiguration and reassembly. Despite a promising water harvesting approach solar steam generation low efficiency remains a challenging obstacle. Here, authors present a macro- and microscopically reconfigurable and magnetically responsive assembly towards a dynamic evaporation system with improved performance and salt resistance.

Harvesting electricity from ubiquitous water vapor represents a promising route to alleviate the energy crisis. However, existing studies rarely comprehensively consider the impact of natural environmental fluctuations on electrical output. Here, we demonstrate a bilayer polymer enabling self-sustaining and highly efficient moisture-electric generation from the hydrological cycle by establishing a stable internal directed water/ion flow through thermal exchange with the ambient environment. Specifically, the radiative cooling effect of the hydrophobic top layer prevents the excessive daytime evaporation from solar absorption while accelerating nighttime moisture sorption. The introduction of LiCl into the bottom hygroscopic ionic hydrogel enhances moisture sorption capacity and facilitates ion transport, thus ensuring efficient energy conversion. A single device unit (1 cm 2 ) can continuously generate a voltage of ~0.88 V and a current of ~306 μA, delivering a maximum power density of ~51 μW cm −2 at 25 °C and 70% relative humidity (RH). The device has been demonstrated to operate steadily outdoors for continuous 6 days. Harvesting electricity from ubiquitous water vapor represents a promising route to alleviate the energy crisis. Here, authors report a bilayer polymer enabling self-sustaining moisture-electric generation by establishing a stable internal water flow through thermal exchange with the environment.