Abstract:In order to study the residual seismic behavior of reinforced concrete（RC）columns，a quasi-static test study was carried out on a full-scale RC column that has undergone a complete pseudo-dynamic test and reached the level of seismic damage of class Ⅱ without strengthening measures. The experimental phenomena, hysteresis curve, bearing capacity, stiffness degradation, ductility coefficient, and energy disspation capacity before and after the quasi-static test are compared and analyzed. The test results show that, the column that has reached the level of seismic damage of class Ⅱ, still retains some seismic capacity without strengthening, and the horizontal force that it can withstand is reduced by around 75%. Finally, the finite element analysis software OpenSees was used to stimulate the column’s hysteresis curve of quasi-static test after the earthquake attack, and a method for simulating the residual performance of RC columns with earthquake damage is proposed, and its reliability is verified.

Abstract:In order to study the uniaxial tensile behavior of half grouted sleeve connection (HGSC) with axial eccentric rebar after fire, uniaxial static tensile tests were carried out on 48 HGSC specimens. The effects of rebar axis eccentricity and high temperature on the mechanical properties of post-fire HGSCs with different rebar diameters are studied, and the engineering opinions are given combined with the existing research. The results show that: post-fire HGSCs with rebar axis eccentricity mainly exhibit rebar fracture and rebar pullout failure. With the increase of the axial eccentricity ratio of rebar and the peak temperature，the transformation from rebar fracture to bonding failure is more likely to occur; Rebar axis eccentricity further affects the connection performance after high temperature. The force of HGSC with axial eccentric rebar decreases to 94% of that of the corresponding specimen without defect at most, and the slip increases to 173% at most; It is suggested that the influence of fire temperature and the axial eccentricity ratio of rebar should be considered in the design, construction, post-fire performance evaluation and repair of HGSC and PC structure with this connection. It is required that there is no rebar pullout failure and obvious bondslip between rebar and grout. Welding can effectively solve the problem of poor thread processing quality.

Abstract:A simplified calculation method considering the stiffness of ordinary floors was proposed in the design of the frame-core tube structure with outriggers, and the results of this method is compared with Finite Element calculating results. Parametric analysis was conducted to evaluate the influences of various factors, such as the number of ordinary floors, the stiffness ratio of ordinary floors, outrigger stiffness ratio, outrigger span ratio and height-tospan ratio. A mathematical formula to calculate the stiffness ratio of the equivalent core tube considering the stiffness of ordinary floors is proposed. And its influencing law on dynamic property of outrigger structures is also compared and analyzed. The results show that the simplified calculation model proposed in this paper can well repeat the results of Finite Element model , the error rate can be reduced by 20% compared with the case without considering the ordinary floor stiffness. The proposed stiffness ratio formula of equivalent core tube can well reflect the contribution of ordinary floors to the overall structure stiffness, and meet the accuracy requirements of engineering scheme design. Moreover, the fitted stiffness ratio calculation formula of equivalent core tube can significantly reduce the computa?tional effort of dynamic analysis and approximately estimate the dynamic characteristics, providing a practical analysis method and theoretical basis for the dynamic analysis of outrigger system.

Abstract:This paper proposed a beam-column composite connection configuration with a single axisymmetric steel beam section to reduce the brittle failure risk of the lower flange welds. The quasi-static tests of three 1∶2 composite connection specimens were conducted. The specimens with the standard steel beam section, narrower beam upper flange and wider beam lower flange with weakened the beam lower flanges only, and widened the beam lower flanges only were considered. The failure process, hysteretic behavior, strain development of key sections, energy dissipation and ductility of each specimen were analyzed in detail. Results showed that composite connection specimens with guaranteed weld quality had full load-displacement hysteresis curves at the loading point, and showed good energy dissipation performance. The plastic hinge of the specimen with widened beam lower flanges occurred in the steel beam section at the end of widened flange plates, and the beam lower flange gradually cracked and extended to the steel web in the process of repeated buckling. Under the positive bending moment, the neutral axis of the composite beam section was close to the beam upper flange, leading to a large strain level at the beam lower flange. The composite connection with a single axisymmetric steel beam section was conducive to moving the plastic hinge away from the column face and thus reducing the strain concentration at the beam’s lower flange. The quality of beam flange butt welds should be guaranteed strictly in practical engineering.

Abstract:In order to reveal the mechanical properties of the adhesively-bonded join between fiber-reinforced polymer（FRP）bridge deck and steel beam, the mechanical behavior of adhesive joints under different tensile/shear combination loads was studied experimentally, including ultimate failure loads, failure modes, stiffness as well as strength failure criterion. Considering the mechanical characteristics of adhesively-bonded joint, six different load combinations of tensile and shear were achieved through a special test device. The results showed that under the pure shear loading, the failure of adhesive joints occurring in the adhesive layer was a cohesive failure at a location close to the steel support. Under the tensile and four combined loading conditions, the failure mode was the combination of fiber breaking (or FRP delamination) and interfacial adhesion failure between the FRP sandwich deck and adhesive layer. Load-deformation curves indicated that the non homogeneous characteristic of the adhesive layer was evident, which induced the eccentric loading on the adhesive joints and stress redistribution during the test process. According to the vectorially separated tensile and shear stress, the tensile-shear strength failure criterion of the adhesive joint was addressed.

Abstract:To investigate the dynamic responses of the train-track-bridge system and running safety under tornadoes, the Kou-wen 3D model is used to simulate the tornado wind field, firstly. The time history of wind loads on vehicles and bridges under the action of moving tornadoes is determined based on quasi-definite theory. Then, the dynamic equations of the vehicle subsystem and track-bridge subsystem are established by using the multibody dynamics approaches and finite element method, respectively. The dynamic equations of the wind-train-track-bridge system are established based on the wheel/rail nonlinear contact relationship, and the dynamic response of the system is solved by the separation iteration method. In the numerical calculations, a road-cum-rail cable-stayed bridge was taken for a case study. The aerodynamic coefficients of bridge and train are determined by wind tunnel test and CFD numerical simulation. The influence of the direction of tornado movement, tornado intensities and running speeds on train-bridge system dynamic response and train running safety is analyzed. The results show that the vertical dynamic response of the bridge is more significant than that of the horizontal, and the vertical wind speed plays a critical role in the vertical displacement of the bridge. When the vehicle passes through the maximum position of wind load, both the lateral and vertical vibration response of the vehicle reaches its maximum value, and the vehicle dynamic response is affected by both tornado load and bridge dynamic response. The maximal running velocity under the EF1 and EF1.3 tornadoes is 180 km/h and 114 km/h, respectively.

Abstract:The lateral position of a passing vehicle crossing the Orthotropic Steel Deck (OSD) is crucial for both OSD bridge fatigue analysis and the Bridge Weigh-In-Motion (BWIM) system. In regard to the local salient effect of OSD bridges, an efficient method is proposed in this work that only uses the collected signals of sensors applied to the BWIM system to identify the lateral position of the passing vehicles. This method establishes the finite element model of OSDs, which can be verified during the calibration test in the BWIM system. The influence lines of girders are then extracted to form the error function between the theory responses and measurements. To verify the accuracy and feasibility of the proposed method, the Ls-dyna-based vehicle and bridge interaction model is first built and analyzed.The effect of vehicle conditions (including the vehicle speed, the number of vehicle axles, and the different wheel lateral positions on the bridge) and wheel-to-bridge contact area on the recognition accuracy is investigated. The simulation analysis shows that the proposed method is not sensitive to vehicle conditions. For different vehicle speeds, the number of axles, the lateral position of the wheels, and the max average errors of the recognition accuracy are 9 mm, 4.6 mm, and 12.5 mm, respectively. In addition, it reveals that the suitable wheel-to-bridge contact area should be 200 mm. Then, a field bridge test is carried out in this paper to verify the effectiveness of this method. The field test results show that the proposed method has high accuracy in identifying the lateral position of the vehicle and has a wide range of applications.

Abstract:A total of 215 typical near-fault ground motion (GM) records were selected reasonably and classified according to the Chinese seismic design code for bridges. Then, the near-fault elastoplastic acceleration and displacement spectra were counted, and the relationship between damping ratio and near-fault elastoplastic spectra was fitted, so as to obtain near-fault elastoplastic demand spectra. By combining the FEMA440 and Chopra capacity spectrum method with the established near-fault elastoplastic demand spectra, a capacity spectrum method considering soil-structure interaction (SSI) effects for Chinese beam bridges was suggested and applied in the seismic performance assessment for a beam bridge under near-fault GMs. The results show that, for the Chinese beam bridge considering SSI effects under near-fault GMs, the results calculated by FEMA440 are conservative, while the results calculated by the proposed method in this study are more reasonable, which can be applied to the seismic performance evaluation for Chinese beam bridges.

Abstract:Cyclic quasi-static tests were carried out on four concrete-filled round-ended stainless steel tubular(CFRST) bridge pier specimens and two concrete-filled round-ended carbon steel tubular (CFRT) bridge pier specimens with different steel tube materials, loading directions and hollow sections. The failure patterns, hysteretic behavior, skeleton curves, ductility ratio and energy dissipation of these specimens were analyzed. The experimental results show that the failure mode of CFRST specimens is the buckling of bottom tubes as well as the crushing of bottom concrete. The hysteretic loops are plump, there are no obvious pinching of curves and the energy dissipation capacity and ductility are good. Compared with round-ended steel tubular bridge pier specimens, the bearing capacity and initial stiffness are almost the same as those of CFRST specimens, the ductility and energy dissipation capacity of CFRST specimens are increased, and the stiffness degradation is decreased. Compared with CFRST specimens with a solid section, the horizontal bearing capacity, initial stiffness, ductility and energy dissipation capacity of CFRST specimens with a hollow section are increased when loading along the strong axis. When loading along the weak axis, the bearing capacity and initial stiffness of CFRST specimens with a hollow section are still higher than those of the specimens with a solid section. But the ductility and energy dissipation capacity of CFRST specimens with a hollow section are slightly lower than those of the specimens with a solid section due to the buckling of the flat portion of steel tubes near the base. A calculation method of the horizontal bearing capacity of the piers is given, and the calculation results are in good agreement with the quasi-static test result.

Abstract:In order to reduce the wind-uplifted damage of standing seam roof system (SSRS) under downburst, a method is proposed to evaluate the reliability of the SSRS under downburst in this article.Firstly, the large eddy simulation (LES) method is used to analyze the roof wind load characteristics under downburst, and the maximum wind load and corresponding distribution position of SSRS are obtained through different wind direction angle conditions.Secondly, the most unfavorable position of SSRS is selected to establish a local simulation model. The corresponding failure criterion and limit state function are derived; Thirdly, the Monte Carlo method based on Latin Hypercube Sampling (LHS-MCS) is used to evaluate the reliability of the SSRS under downburst. Finally, the analysis results are evaluated in combination with conventional wind reliability indicators and related specifications. The research results show that downbursts are more likely to cause wind-uplifted damage to the SSRS than conventional winds. At the same time, the reliability index under downbursts only meets the third-level safety level required by the specification. It is recommended to consider the impact of the downburst when designing the SSRS for important buildings.

Abstract:A new type of Eddy Current Damping-Rack and Gear Wall (ECD-RGW) was proposed, then Finite Element Method（FEM）simulation was performed and ECD-RGW parameters were analyzed. Firstly, construction of ECD-RGW was introduced in detail. Whereafter, the mechanical performance of ECD-RGW was studied by using COMSOL Multiphysics (a multi-physical finite element simulation software), and 5 dominating design parameters were analyzed. Finally, the vibration reduction effect of ECD-RGW is evaluated, and compared with the Fluid Viscous Damper（FVD）. The results show that, ECD-RGW, as a new eddy current damping device, has good mechanical behavior. Its damping performance can be significantly improved by reducing the air gap length, installing the back iron of conductive plate and increasing the number of permanent magnets, which the existence of conductor plate back iron increases the equivalent damping coefficient of ECD-RGW at low speed to more than 4 times. Furthermore, the material of the conductive plate has a great influence on the critical velocity which is corresponding to the peak damping force, and the thickness of the conductive plate influences the peak damping force and critical velocity. In addition, ECD-RGW has a good vibration reduction effect, which means its application is feasible.

Abstract:The real mountains are rugged and complex. The slopes on both sides of the ridge line are generally different, showing obvious asymmetry. To better reflect the terrain and wind field effects of real mountains, a simplified model of the cosine-shaped mountain range with variable cross-section is proposed based on the cosine-shaped mountain range. Based on Computational Fluid Dynamics（CFD）numerical simulation, the horizontal mean wind speed-up ratio is compared between the real mountain range, the cosine-shaped mountain range, and the variable cross-section cosine-shaped mountain range in the wind direction parallel to the mountains. The rigid rod method is used to calculate the wind-induced swing response of transmission lines at different positions. The results show that the horizontal mean wind speed-up ratios in the terrain feature points are consistent between the variable cross section cosine-shaped mountain range and the real mountain range. At 50 m above the ground, the horizontal mean wind speed-up ratio along the ridge line of the variable cross-section cosine-shaped mountain range is basically the same as that of the real mountain range. Due to the limitation of parameters, the trend of the ridge line of the cosineshaped mountain range is relatively independent, and its horizontal mean wind speed-up ratio is quite different from that of the real mountain range. The wind-induced swing calculated by variable cross-section cosine-shaped mountain range can much better reflect that of the real mountain range. Although the vertical wind speed of the variable cross-section cosine-shaped mountain range is quite different from that of the real mountain range, the former can better reflect the horizontal mean wind field of the latter. The proposed simplified model has similar wind field effects.

Abstract:To study the effect of interface modification and temperature on the interface performance of Textile Reinforced Concrete (TRC), the textile surface with epoxy resin, silane coupling agent and nano-silica（SiO2）were treated, respectively. The scanning electron microscope, and pull-out test were conducted to study the micromorphology and macro-mechanical properties of TRC specimens at 25 ℃, 100 ℃, and 200 ℃. The test results show that both nano-SiO2 impregnation and epoxy resin coating can significantly improve the interfacial properties between carbon fiber and the cement matrix. Nano-SiO2 particles can be immersed into the fiber bundle, which improves the stress transfer between the internal fiber filaments and the matrix, and nano-SiO2 reacts with calcium hydroxide to form a calcium silicate hydrate gel, which improves its bonding performance. The silane coupling agent treatment can increase the surface roughness of the fiber, enhance the amount of nano-SiO2 adhered to the fiber, and then improve the bonding strength along the interface with the cement base. The interfacial strength of carbon fiber bundles impregnated with nano-SiO2 at 100 ℃ and 200 ℃ was significantly higher than that impregnated with epoxy resin. This study can provide a reference for TRC mechanical properties design and thermal stability improvement methods.

Abstract:In order to study the bearing behavior of a single pile under combined vertical-torsional（N-T）loads in sand overlying clay soils, based on an indoor model test, a series of load-displacement curves and inner force distribution of pile shaft under combined N-T loads were obtained. By dimensionless treatment and curve fitting, the envelope of pile bearing capacity and its simplified calculation formula were obtained. Further numerical simulation on the single pile under combined N-T loads was carried out by ABAQUS to find out the influence law of elastic modulus（Ep），slenderness ratio（L/D）and relative thickness of the sand layer（lu/L）on the pile behavior. Results show that compared with a pile under a single load, the ultimate vertical and torsional bearing capacity of pile under combined N-T loads obviously decrease, and applying N（or T）causes the increase in twist angle（or settlement）of the pile shaft. It is also found by numerical analysis that pile deformation mainly occurs in the range of 0~0.6L，increasing L/D and lu/L causes the bearing capacity of the pile shaft significantly increase, but increasing Ep has little effect on improving the pile capacity. Therefore, it is suggested that the effective method to improve the bearing capacity of the pile shaft is to appropriately increase pile length or thickness of the sand layer. Additionally, obvious sudden changes of stress occur at the interface between upper and lower soil layers.

Abstract:Based on practice engineering of pile-soil interaction induced by side-crossing tunneling, a simplified calculation method is proposed to evaluate the lateral displacement of the existing pile. The two-stage method is selected to get a simplified calculation method of the horizontal displacement of adjacent piles caused by shield tunneling. In the first stage, the Loganathan formula is applied to calculate the horizontal soil-free displacement at the pile axis caused by shield tunneling. In the second stage, the pile is simplified as an Euler-Bernoulli beam lying on the Vlasov foundation model, then the governing equation of horizontal displacement of the pile is established. After considering the boundary of the pile, the analysis of the mathematical matrix of tunneling on the adjacent pile is obtained by using a finite different method. Next, taking the soil blocking effect between pile groups into consideration, further, the difference solution for horizontal displacement of adjacent pile groups can be detected. By comparing with actual measurement in two engineering cases, the superiority of the proposed method can be verified. The parameters analysis of group piles shows that the horizontal displacement of adjacent pile groups increases with the increment of tunnel buried depth and ground loss ratio, but the depth of maximum displacement occurrences increases with the increase of the buried depth of the tunnel. The increase of the tunnel-pile horizontal distance causes the decrease of the horizontal displacement of the adjacent pile groups, but the rate of decrease slows gradually.

Abstract:The construction process and mechanical characteristics of a double-lining water shield tunnel should be considered in the design, and the uncertainty of the stratum also affects the safety performance of the structure. Therefore, combined with the stress characteristics of double lining water conveyance tunnel, based on the limit state design principle, the two-stage method is adopted to calculate the two force states, which include the outer lining bearing the external pressure alone and the inner and outer lining bearing the internal and external pressure together. The section force, convergence deformation and the maximum crack width are all constrained in safety. The cross-section robust design method and the process of double lining water conveyance shield tunnel are established, and the structural design parameters are optimized combined with the actual engineering case. The results show that the robust design process takes into account the sensitivity of the structure to the variation of stratum and the cost of materials, and introduces the constrained multi-objective optimization algorithm to obtain the complete threedimensional Pareto front surface. The two-dimension optimization of cost-robustness was realized by unifying the robustness indexes under the two limit states by the weighting method. By dividing the tunnel into sections and extracting typical sections, the problem of parameter variation in different longitudinal sections can be effectively solved to ensure the unification of parameters in tunneling and tunnel safety.

Abstract:At present, offshore wind power is developing continuously in Bohai bay. Ice-induced vibration response is an important problem faced by offshore wind turbines in Bohai bay. Based on the integrated numerical analysis software of offshore wind turbines, the dynamic response of single pile offshore wind under floating ice load is studied. This paper focuses on investigating the variation law of load dynamic response of monopole offshore wind turbines, studies the influence of different ice load numerical models, ice thickness, and ice velocity on monopole offshore wind dynamic response, and carries out the influence law of single pile offshore wind dynamic response of icebreaking cone structure. The results show that the calculation results under different ice load numerical calculation models are quite different. The tower foundation load and mud line load calculated by Matlock double tooth model are the largest, which are 2.2 times and 1.3 times of that without floating ice, respectively; The dynamic response of single pile offshore wind turbine increases with the increase of ice thickness, and the change of ice velocity has no obvious effect on the structural load of single pile offshore wind turbine. After the ice-breaking cone is adopted, the ice load acting on the single pile offshore fan is significantly reduced, and the shear and bending moment at the tower foundation and mud surface line of the monopile offshore wind turbine are greatly reduced. The maximum values of the shear and bending moment at the tower foundation are 82% and 95% of the structure without an ice-breaking cone, respectively. At the same time, the ice-breaking cone structure can greatly reduce the ice load on the structure,and its maximum ice load and standard deviation are 5% and 7% of that structure without an ice-breaking cone, respectively.

Abstract:Soil arching is the key factor of load transfer in a pile-supported embankment. Its development and stability under cyclic loading will directly affect the bearing capacity of the embankment. Based on the laboratory model test, a series of particle flow numerical models of the pile-supported embankment are established by using PFC2D software, and the correctness of the models verified by the laboratory model test results. Based on the discrete element numerical models, the embankment is subjected to vehicle cyclic loads simulated by sinusoidal wave loads, and the development and reduction of soil arching in pile-supported embankment under cyclic loading are analyzed. The numerical results show that the ratio of embankment height to pile spacing, cyclic load amplitude，and frequency all affect the soil arching in the piled embankment, while the variation of the ratio of embankment height to pile spacing significantly influences the soil arching reduction coefficient. The ratio of the embankment height to the pile spacing is an important factor affecting the stability of the soil arching in the piled embankment subjected to cyclic load. Hence, the expression of the soil arching reduction coefficient is derived based on the analysis and curve fitting of discrete element numerical results by taking those factors into consideration.

Abstract:To reveal the time-dependent deformation and damage characteristics of the carbonaceous mudstone reservoir bank slope, using a low-field nuclear magnetic resonance test and triaxial compression rheological test, the pore evolution law and creep characteristics of carbonaceous mudstone under wetting and drying cycles are studied.On this basis, based on the damage theory and the Lemaitre strain equivalence principle, a creep damage equationconsidering the coupling effects of wetting and drying cycles, axial pressure, and time is established. The results show that as the number of wetting and drying cycles increases, the porosity of the carbonaceous mudstone increases, the pore structure changes from small pores to large pores, and the instantaneous strain and creep strain of the carbonaceous mudstone increase. The established damage equation can better characterize the influence of the number of wetting and drying cycles, axial pressure, and time on the damage evolution of carbonaceous mudstone. With the increase in the number of wetting and drying cycles, the damage of carbonaceous mudstone is greater, and the damage time effect is more significant. As the axial pressure increases, the rate of damage growth is fastened, and the duration of the accelerated damage is prolonged.

Abstract:In order to explore the engineering mechanical properties of the aeolian sand subgrade treated by pyrolysis residue of oil sludge, the compaction characteristics, resilience modulus, California bearing ratio (CBR), and direct shear characteristics of the aeolian sand subgrade with different content of oil sludge pyrolysis residue, as well as the unconfined compressive strength with 25% content of residue were studied through laboratory tests. The results show that the maximum dry density is 2.071 g/cm3 when the content of oil sludge pyrolysis residue is 25%; the maximum rebound modulus is 160.61 MPa when the content is 15%; the CBR increases continuously with the increase ofresidue content, the CBR value of the sample decreases obviously after soaking in water, within the decrease ranging from 10.97% to 38.46%; the maximum internal friction angle is 34.35° when the content is 20%; the unconfined compressive strength values of the sample with 25% residue content exceed 0.4 MPa at 14 d and after 14 d. The comprehensive test results show that the pyrolysis residue of oil sludge can effectively improve the mechanical properties of the aeolian sand subgrade, and the residue can be used as filling material for the aeolian sand subgrade.

Abstract:To overcome the problems of insufficient natural lighting and weak light comfort for traditional residential buildings in Tibet, a design method for a feasible multifunctional window system is proposed. The novel system is mainly composed of a photovoltaic power generation panel, reflective panel, thermal insulation panel, and rotating shaft. Based on the above method and for typical cases, a theoretical analytical model of multifunctional windows was established in 3 operational patterns: summer, winter, and transitional season, and field tests were conducted for verifying the data accuracy. The results show that, compared with the same size traditional window, a multifunctional window increases southern indoor natural lighting depth by 5 times for 10 h in the transition season, increases the lighting depth by 2.5 times (above 7.5 m) for 9 h in winter, and increases daylight factor by 0.5% in summer; the average monthly power generation of photovoltaic power generation panel in summer is 9kW·h, and the annual photovoltaic power generation reaches up to 90kW·h. The multifunctional window increases the temperature difference between the inner and outer surfaces of the window in winter and summer by about 3～8 ℃ and 2～4 ℃, respectively,and reduces the temperature difference between the inner surface of the window and wall by about 2～4 ℃ in winter,and the inner surface temperature of the window is closer to the indoor temperature. Overall, the multifunctional window has the characteristics of low cost, diverse functions, remarkable effect, and strong economic competitiveness. It is of important significance in other advanced window designs and practical applications. It can be directly applied in the repair of the old building window as well as the new ones in the Tibet rural area.

Abstract:In order to explore the impact of temperature step change on the thermal comfort of the human body under radiant air-conditioning mode and provide a certain reference for the control and adjustment of radiation airconditioning systems, this study explored the change law of total and local subjective thermal response, thermal comfort and skin temperature with time for 20 subjects under three different air conditioning modes (convection, radiant floor, and radiant ceiling), by creating a cool-neutral temperature step change in an artificial well-controlled climate chamber. The testing results of the above physiological parameters show that the skin temperature in the mutation to the radiant neutral environment exists a hysteresis, and human sympathetic nerves perform more actively in a dynamic radiant environment. Subjective questionnaire analysis shows that the subjects’comfort and thermal pleasure are better in the dynamic radiant heat environment, and subjective thermal sensations appear psychological advance ment, with more prominent advantages of the dynamic radiant floor; and the back, calves, and feet are the of the average skin temperature of the human body over time. A correlation model based on the Knothe function was established to quantify the response characteristics of human physiological adjustment under three conditions. Finally, according to the change law of the average skin temperature and its rate of change and the average thermal sensation, thermal sensation prediction models for three conditions are established, which simplify the solution of human thermal sensa?tion prediction in a dynamic environment.

Abstract:Aiming at the problem that it is difficult to determine the dosage of coagulant for algae outbreak in waterworks, a prediction method of algae coagulation removal rate based on deep learning is proposed. DenseNet convolution neural network and floc image are used to predict the algae coagulation removal rate, so as to adjust the dosage. The specific method is to coagulate the high algae water under laboratory conditions, and record the floc image and the corresponding removal rate range after coagulation. The floc image data set was constructed with the removal rate interval as a label, and the DenseNet-121 model was trained with this data set. The results show that the prediction accuracy of the trained model for the test set reaches 89.5%. Compared with VGG and RESNET convolution neural network, the DenseNet convolution neural network has higher recognition accuracy on the data set established in this paper and has obvious advantages over the other two models in identifying floc images with a removal rate of 60%~90%. At the same time, the recognition of Microcystis aeruginosa floc image outside the data set verifies the good generalization of the model.