• Volume 41,Issue 5,2024 Table of Contents
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    • Influence of Rust Inhibitors on Rebar Corrosion in Sea Sand Sulfoaluminate Cement Concrete

      2024, 41(5):1-7. DOI: 10.3969/j.issn.1673-9469.2024.05.001

      Abstract (110) HTML (0) PDF 3.87 M (149) Comment (0) Favorites

      Abstract:In this study, sea sand was used to prepare sea sand sulfoaluminate cement concrete (SACS) by substituting river sand. Sea sand ordinary Portland cement concrete (OPCS) was used as the control group. The chloride ion solidification performance of SACS was investigated. The effects of different rust inhibitors (sodium monofluorophosphate, lithium nitrite, and triethanolamine) and their concentrations (0%, 0.5%, 1%, 1.5%, 2%, i.e., the mass ratio of rust inhibitors to sulfoaluminate cement) on rebar polarization potential and rebar corrosion in sulfoaluminate cement mortar (SS) were studied using the methods of hardened mortar anode polarization and rebar mass loss. The results showed that after 28 days of curing, the chloride ion solidification rate of SACS was approximately 18% higher than that of OPCS. The rebar polarization potential in SS was slightly higher than that in sea sand ordinary Portland cement mortar (OPCS). Adding rust inhibitors to SS shifted the rebar polarization potential in a positive direction and reduced the mass loss. The best rust inhibition effect was achieved by adding 1.5% triethanolamine, meeting the specifications for the change in rebar polarization potential, and the rebar mass loss was only 0.014 2%, approximately 91% lower than that without adding rust inhibitors.

    • Prefabricated Building Component Recognition Method Based on Improved View Clustering

      2024, 41(5):8-15. DOI: 10.3969/j.issn.1673-9469.2024.05.002

      Abstract (102) HTML (0) PDF 11.92 M (117) Comment (0) Favorites

      Abstract:In order to realize the intelligence of the production, storage and assembly process of prefabricated building components, an online recognition method based on improved view clustering was designed. By adding label information embedding and label information solidification into the information bottleneck algorithm, the traditional view clustering algorithm was improved into an unsupervised pattern recognition method which could be used for online recognition of prefabricated building components. The method was tested on the real data set of an industrial construction company in Tianjin, and the experimental results show that the model recognition accuracy is above 90%, which is superior to Softmax neural network, support vector machine, Bayesian network and other supervised pattern recognition methods.

    • Experimental Study on Mutally Embedded Settlement Between Different Kinds of Soft Soil and Miscellaneous Fill

      2024, 41(5):16-26. DOI: 10.3969/j.issn.1673-9469.2024.05.003

      Abstract (60) HTML (0) PDF 10.26 M (107) Comment (0) Favorites

      Abstract:In order to study the settlement patterns of different types of soft soil and miscellaneous fill soil, indoor settlement tests were conducted on different types of soft soil and overlying miscellaneous fill soil under di-fferent loads and liquid indices, with the underlying silt soft soil as the research object. The temporal development patterns of total settlement, consolidation settlement, and mutally embedded settlement of different types of soft soil and miscellaneous fill soil foundations at 50, 100, 150 kPa, as well as the temporal development patterns of total settlement, consolidation settlement, and mutally embedded settlement of different soft soils with liquid indices of 0.8, 1.0, 1.2 and miscellaneous fill soil foundations at 100 kPa were analyzed. The research results indicate that the mutally embedded settlement and mutally embedded settlement completion of the three soil samples increase with the increase of load and liquidity index, respectively. For different soil samples, the mutally embedded settlement of high liquid limit soil is greater than that of low liquid limit soil, and the mutally embedded settlement completion has different variation patterns at different liquidity indices.

    • Mechanical Characteristics of Expansive Soil Contaminated by Manganese Ions

      2024, 41(5):27-35. DOI: 10.3969/j.issn.1673-9469.2024.05.004

      Abstract (48) HTML (0) PDF 19.86 M (98) Comment (0) Favorites

      Abstract:In response to the mechanical characteristics of contaminated expansive soil, unconfined compressive strength and direct shear tests were conducted to explore the changes in mechanical characteristics at the macroscopic level, combining SEM experiments to analyze the changes in microstructure. After XRD experiments, JADE analysis software was used to quantitatively analyze the collected raw data and obtain the trend of changes in the proportion of each phase content in the sample, in order to explore the mecha-nism of changes in the mechanical properties of expansive soil. The experimental results show that under the same compaction degree and Mn2+ concentration, the expansive soil sample with the optimal moisture content has the highest strength; Under the same initial moisture content, the strength, internal friction angle, and cohesion of the sample all show an increasing trend with the increase of Mn2+ concentration; Quantitative analysis of the phase by JADE indicates that SiO2 in the soil shows an increasing trend after being contaminated with Mn2+. The reason is that the hydrolysis of Mn2+ in MnSO4 solution indirectly leads to the hydrolysis of silicate minerals in the expansive soil sample, releasing SiO2 and increasing the bonding effect between soil particles, thereby improving the overall integrity and stability of the soil.

    • Experimental Study on Mechanical Properties of Self-compacting Cemented Soil Under Wet-Dry Cycles

      2024, 41(5):36-43. DOI: 10.3969/j.issn.1673-9469.2024.05.005

      Abstract (133) HTML (0) PDF 8.24 M (98) Comment (0) Favorites

      Abstract:In order to explore the effect of dry-wet cycles on the mechanical properties of self-compacting soil-cement, the unconfined compressive strength of self-compacting cemented soil under different dry-wet cycles was compared and analyzed through experiments, and the appearance damage degree and strength deterioration law of self-compacting cemented soil were discussed. According to the strength decay law, an empirical formula between the dry-wet cycle number and strength deterioration was established. It is found that the strength decay rate of self-compacting cemented soil after the jth dry-wet cycles is j0.3 times that of the first cycle. The peak strength of the stress-strain curve of self-compacting cemented soil gradually decreases with the increase of the number of dry-wet cycles, and the failure type of sample changes from brittle failure to plastic failure.

    • Experimental Study on Electroosmotic Effect of Different Electrode Materials Under Two Moisture Contents

      2024, 41(5):44-49. DOI: 10.3969/j.issn.1673-9469.2024.05.006

      Abstract (21) HTML (0) PDF 8.54 M (80) Comment (0) Favorites

      Abstract:Taking clay as the test object, the self-made one-dimensional horizontal electroosmosis device was used to analyze the parameters such as drainage, current, energy consumption and final moisture content of soil, and the electroosmosis effects of three electrode materials of stainless steel, copper and aluminum under two moisture contents were explored. The results show that the electroosmotic effects of the three electrode materials are in the order of stainless steel electrode>copper electrode>aluminum electrode under two moisture contents. The initial moisture content has little effect on stainless steel and copper electrodes, but has a great effect on aluminum electrodes. The electroosmotic effect of aluminum electrodes is very poor at a lower moisture content. The initial moisture content will affect the degree of chemical reaction of the anode. By comparing the tests of three electrode materials under two moisture contents, it is concluded that the higher the initial moisture content of the soil is, the better the drainage effect is and the greater the total energy consumption is, but the energy consumption per unit drainage is smaller.

    • Optimization of Boom Force and Construction Control of 130 m Arch with Bridge Medium-bearing Basket-Tie Steel

      2024, 41(5):50-55,77. DOI: 10.3969/j.issn.1673-9469.2024.05.007

      Abstract (44) HTML (0) PDF 6.28 M (83) Comment (0) Favorites

      Abstract:The finite element analysis software MIDAS Civil was used to study the Boshuiwan Bridge in Shijiazhuang City. The reasonable bridge state calculated by zero displacement method, rigid support continuous beam method and minimum bending energy method was compared and analyzed. The forward iteration method was used to calculate the boom tension of three different tensioning sequences, and the impact matrix method was used to correct the boom force value to determine the better tensioning sequences. Based on the research results, the minimum bending energy method has a more uniform distribution of the boom force of the bridge, and the problem that the end boom force has a larger deviation from the middle boom force is basically eliminated, and the maximum bending moment of the arch rib is small. The overall distribution of bending moments at the end of the tie beam and the arch rib is more uniform. By comparing three different boom tensioning sequences, the tensioning sequence one is tensioning from the mid-span to the beam end, the tensioning sequence two is tensioning from the beam end to the mid-span, and the tensioning sequence three is the jumper tensioning. The tensioning sequence one is superior to the tensioning sequence two and the tensioning sequence three in terms of construction economy and rationality. Three groups of boom forces under different tension sequences are iterated. Although the maximum deviation value of boom force is reduced, the boom force calculated iteratively according to tension sequence 1 is better than that calculated iteratively according to tension sequence 2 and tension sequence 3.

    • Deformation Analysis of Bridge Pile Foundation of Metro Shield Tunnel Side Passing Existing Railway Bridge at Different Angles

      2024, 41(5):56-63. DOI: 10.3969/j.issn.1673-9469.2024.05.008

      Abstract (77) HTML (0) PDF 11.89 M (106) Comment (0) Favorites

      Abstract:When a subway shield tunnel passes through an existing railway bridge on the side, it will have varying degrees of impact on the bridge pile foundation, and different angles of passing will cause different deformations in the soil and bridge piles within the intersection range of the two. Based on the construction of a shield tunnel under a railway bridge in the northern section of Tianjin Metro Line 4, a three-dimensional numerical analysis model of the tunnel soil pile foundation bridge system was established. Combined with actual engineering measurements, the impact of tunnel excavation on the bridge pile foundation was analyzed for four lateral crossing conditions at angles of 85°, 80°, 76°, and 70° between the tunnel and the railway bridge. The results indicate that changes in the crossing angle will have varying degrees of impact on the deformation and stress of bridge pile foundations. The smaller the crossing angle, the greater its impact on the deformation of bridge piles, and there exists an optimal crossing angle. When the optimal crossing angle of 90° cannot be selected in practical engineering, se-tting isolation piles between the tunnel and bridge piles for reinforcement can effectively reduce surface settlement and pile foundation deformation, thereby protecting the existing bridge.

    • Experimental Study of Phase Change Energy Plus Heat Pump Heating System

      2024, 41(5):64-70. DOI: 10.3969/j.issn.1673-9469.2024.05.009

      Abstract (33) HTML (0) PDF 9.00 M (78) Comment (0) Favorites

      Abstract:In view of the problem that there is no suitable heat source for heating in winter in the mountainous areas of northern China, in this paper, based on the principle of solidification and heat exchange of water-ice phase change, the latent heat of solidification of water phase change is used as the low-temperature heat source of heat pump unit, and the phase change energy plus heat pump heating system is designed and developed and experimentally studied. The results show that when the icing thickness reaches 30 mm in the solidification and heat exchange stage of the system, the comprehensive heat transfer coefficient is 151 W/(m2· K), and the Coefficient of Performance (COP) is 3.52. The design cycle is 4 h and the heat transfer coefficient is 150 W/(m2· K), in order to determine the energy storage capacity and heat transfer of the U-shaped ice storage tank. The energy consumption of ice melting accounts for 5.6%, and the ice melting time is 26 min. The experimental system can meet the heating needs of a house of 210 m2.

    • Study on Height of Overlying Rock Water-conducting Zone in Thick Coal Seam Mining

      2024, 41(5):71-77. DOI: 10.3969/j.issn.1673-9469.2024.05.010

      Abstract (43) HTML (0) PDF 19.20 M (92) Comment (0) Favorites

      Abstract:Regarding the issue of roof water inrush caused by disturbance to the overlying rock during coal mining under water bodies, in this paper, the 15102 working face of Zhangshigou coal mine is taken as the research object, and the development height of the water-conducting zone of the 15# coal seam of this working face is obtained by the numerical simulation, segmented plugging and leakage testing and drilling TV method. The simulation analysis and actual measurement results shows that the heights of the water-conducting zone are 49 m and 48.3 m from the simulation and field observation, respectively. The final height of the water-conducting zone is 48.3 m, the fracture-mining ratio is 11.78, and the rock layer type at the upper interface is sandy mudstone, with a thickness of 4.2 m and a distance of about 48 m from the coal seam.

    • Estimation of Heat Removal Potential of Medium-Deep U-shaped Buried Pipe Based on Uniform Design

      2024, 41(5):78-84,94. DOI: 10.3969/j.issn.1673-9469.2024.05.011

      Abstract (25) HTML (0) PDF 2.54 M (78) Comment (0) Favorites

      Abstract:In order to estimate the heat extraction potential of the U-shaped underground heat exchange system in the middle and deep layers, a simulation verification was carried out using a U-shaped buried pipe heat exchange model programming in the middle and deep layers. Taking into account six factors including the soil thermal conductivity, vertical pipe length, ground temperature gradient, horizontal pipe length, soil density, and constant temperature layer temperature, a uniform experimental design method was used to design a simulation test plan. Multiple linear regression method was used to analyze the relationship between the six factors and the heat extraction, and a prediction equation for the heat extraction was established. The results shows that the maximum stable heat transfer of the U-shaped bu-ried pipe heat exchanger in the middle and deep layers can be predicted using five factors including the soil thermal conductivity, vertical pipe length, ground temperature gradient, horizontal pipe length, and constant temperature layer temperature. The maximum stable heat transfer prediction value is obtained. The average error compared to the simulated value is 6.76%, and the maximum relative error is -9.88%.

    • Numerical Simulation Analysis of Thermal Recovery Effect of Multi Energy Complementary System in Aquifer Reservoirs

      2024, 41(5):85-94. DOI: 10.3969/j.issn.1673-9469.2024.05.012

      Abstract (47) HTML (0) PDF 9.96 M (80) Comment (0) Favorites

      Abstract:A multi energy complementary system based on aquifer reservoirs was constructed, and the temperature response characteristics of the aquifer multi energy complementary system and the temperature variation law of the production well were analyzed. The influences of the reinjection temperature, bottomhole pressure difference, and well spacing on the temperature of the production well were explored. Finally, the significance of each factor was analyzed through the response surface methodology. The results indicate that the system can effectively extend the service life of geothermal wells and achieve the function of outputting stable energy by exchanging and balancing fluctuating energy through heat exchange within the formation. Increasing the reinjection temperature can slow down the decrease in temperature of the production well. Increasing the bottomhole pressure difference can shorten the equilibrium heat production time and accelerate the temperature drop of the production well. Increasing the well spacing can prolong the stability time of the production well and slow down the temperature drop of the production well. With the response surface analysis method, the primary and secondary order of the four factors affecting the water temperature of production wells was analyzed as: well spacing>bo-ttomhole pressure difference>reinjection temperature>service life. The interaction between reinjection temperature and well spacing had the greatest impact.

    • Investigation of Solvents' Influences on Fe-MnOx Catalyst for Utra-low Temperature NH3-SCR

      2024, 41(5):95-102. DOI: 10.3969/j.issn.1673-9469.2024.05.013

      Abstract (42) HTML (0) PDF 10.81 M (99) Comment (0) Favorites

      Abstract:Aiming at the influence of different solvent environments on Fe-MnOx catalysts during the preparation process, Fe-MnOx catalysts were prepared by a one-step co-precipitation method. The inf-luence of different solvent environments on catalyst activity during the synthesis of the catalyst was investigated. It was found that the catalyst prepared by glycerol as a solvent environment had the best low-temperature activity and sulfur resistance. Through a series of characterization analyses, it was found that the catalyst prepared in a glycerol environment has regular particle morphology and particle size, the largest specific surface area, abundant and evenly distributed pore structure, and the highest contents of Mn4+, Fe3+ and Oα. Therefore, under the condition of 50 ℃ and GHSV=30 000/h, the catalyst can be used to improve the quality of the catalyst. It shows more than 80% NO<em>x removal rate and better sulfur resistance.

    • Research on Random Scheduling Optimization of Cloud Manufacturing Service Based on Improved Grey Wolf Algorithm

      2024, 41(5):103-112. DOI: 10.3969/j.issn.1673-9469.2024.05.014

      Abstract (46) HTML (0) PDF 4.33 M (88) Comment (0) Favorites

      Abstract:To study the random scheduling problem of dispersed manufacturing resources in the context of cloud manufacturing, the service time is set as an uncertain production parameter, a random scheduling model is established, and an improved grey wolf algorithm combined with reinforcement learning is used to solve it to optimize the scheduling scheme. Starting from the perspectives of cloud platforms, users, and service providers, a multi-objective mathematical model based on uncertain environments is proposed. At the same time, the Grey Wolf Algorithm is combined with reinforcement learning, Q-learning is used to adjust parameters, and dual populations are explored and mined separately to prevent falling into local optima and to solve medium to large-scale instances. By conducting comparative expe-riments to evaluate the performance of the algorithm, it was found that the algorithm showed the best performance in all 16 cases, which can improve processing efficiency and increase stakeholder benefits. Sensitivity analysis was also conducted on the algorithm parameters to verify their rationality and applicability.

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