Abstract:To apply the UHPC elements in building construction， this paper proposes a fully prefabricated spliced channel-shaped section UHPC beam. The beam is designed with bolt ribs that have through bolt holes. Two ribbed channel-shaped section beams are installed through forward and reverse splicing to form two kinds of fully assembled combination connection modes of beams and columns， i.e.， I-type and box-type. To study the bending and shear resistance of the spliced UHPC beams， three beam bending experiments were conducted， including cast-in-place I-beam， box-type spliced beam， and I-type spliced beam. Through the bending test， it was found that the stiffness of the spliced beam was slightly higher than that of the cast-in-place beam， and the bending capacity of the I-type spliced beam was higher than that of the cast-in-place beam， thus proving that the bending resistance of the UHPC spliced beam was better than that of the UHPC cast-in-place beam. To study the shear resistance of the I-type spliced beams， shear tests of nine I-type spliced beams were completed by setting different shear-to-span ratios and stirrup spacing through orthogonal test design. The cracking load， failure loads， deformation， and crack distribution laws were obtained. The shear test revealed that， with the same stirrup spacing， the failure mode of the I-type spliced beam was diagonal-compression and shear-compression failure， respectively， as the shear-span ratio was increased from 1 to 2 or 3. For the beam with stirrups and the same stirrup spacing， the larger the shear-span ratio， the lower the load-carrying capacity and the better the ductility of the channel-spliced beam. Moreover， the stirrups in the beams had a restraining effect on the development of the main cracks.

Abstract:To realize the rapid inspection of a large amount of small and medium-span bridges， a modal identification method based on the response of moving vehicles is studied. And a moving inspection vehicle with adjustable parameters is proposed. The vehicle parameters are optimized by theoretical derivation， experimental verification， and parameter research. Firstly， an analytical solution of the dynamic response of the specially designed “tractor-double-trailer” vehicle moving along the bridge is derived based on the vehicle-bridge coupled vibration theory. Then， the analytical solution is verified by the numerical results using a self-developed vehicle-bridge coupled analysis program， as well as the field test results of a simply supported beam bridge. Finally， the influence of various factors， such as vehicle parameters， vehicle speed， and bridge parameters， on the identification accuracy is analyzed using the analytical solution. The results show that when the natural frequency of the trailer is 0.8~0.9 （or 1.1~1.2） times the bridge frequency， the performance of the bridge frequency identification using the proposed method is better. It is suggested that the speed of the moving vehicle should not be taken too high. Based on different cross-section areas， cross-section shapes， and spans of the bridge， a reasonable selection of vehicle parameters can improve the accuracy of bridge modal identification. The findings of this paper can provide a good reference for bridge frequency identification using the moving vehicle in practice.

Abstract:The variation of bonding performance between pavement layers of cement concrete bridge decks with temperature was studied， and the relationship between the temperature properties of the bonding layer and the shear strength of straight shear and oblique shear was explored. The differences in pulling and shear strength of four coating adhesive layers （SBS modified asphalt， WTR modified asphalt， WTR/APAO modified asphalt， AMP-100 second-order reactive adhesive coating） and three modified asphalt crushed stone bonding layers （SBS modified asphalt crushed stone， WTR modified asphalt crushed stone， WTR/APAO modified asphalt crushed stone） were compared and analyzed. Regression analysis was used to obtain the variation law of interlayer intensity with temperature. The study calculated the ratio of the strength between the lower layers and the strength between the lower layers at normal temperature （20 ℃）， which was used for the comparative analysis of the temperature sensitivity of the shear strength and the pull strength of the bonding layer； The ratio of oblique shear strength to straight shear strength at different temperatures was also analyzed. The results show that the pull strength between layers， shear strength， and temperature between layers all meet the relationship of a single exponential function， with a goodness of fit R2 above 0.970. The WTR/APAO modified bitumen bond layer and WTR/APAO modified asphalt crushed stone bond layer have excellent mechanical properties， with higher pull and shear strength values at different temperatures than those of the same type of bonding layer. The pulling and shear strength of the AMP-100 bond layer is the least sensitive to temperature. An interlayer strength ratio table of 20~40 ℃ was established for interlayer strength estimation. The oblique shear strength is significantly higher than the straight shear strength， and the sensitivity of the oblique shear strength to temperature is lower than that of the straight shear strength. At temperatures ranging from 20℃ to 45 ℃， the ratio of oblique shear strength to straight shear strength ranges from 1.165 to 2.990.

Abstract:To propose a precise and convenient solution method for in-plane vertical modes of cable-stayed bridges， a new dynamic model comprised of lumped mass beam segments was established in this paper， which was used to simulate the in-plane vertical natural vibration behavior of cable-stayed bridges. In the model， the cables were reduced to vertical elastic supports and external forces on the girder in the horizontal direction. Additionally， the shear forces on both sides of the micro beam-segment were introduced to simulate the actions of the beam’s bending stiffness and the coupled interaction between the cables. Based on the moment equilibrium between the beam segments and the finite difference method， the solutions of the in-plane vertical modal frequencies and shapes of cable-stayed bridges of different systems can be obtained. A computational solution program was also developed. The theoretical solutions were compared to field-test results from an actual bridge， confirming that the model and method proposed in this paper can accurately calculate the modal properties of in-plane vertical modes of cable-stayed bridges. The results through parametric analysis showed that the effect of the beam’s axial force was more significant on the low-order modal. The phenomenon of a transition on the low-order mode was observed when the axial force was increased to a high value. Moreover， when the cable is broken， the influence on each mode is related to the corresponding mode participation coefficient of the beam segment anchored with the cable.

Abstract:To reveal the force transmission mechanism of a novel steel-concrete joint in the large-span hybrid continuous girder bridges， a large-scale model of a steel-concrete joint with a geometric scaling ratio of 1∶3.5 was designed and fabricated based on the Fuzhou Mawei Bridge. And a refined solid finite element method was also used for static loading analysis under different design load combinations. The results show that， under the load-bearing capacity limit state condition， the concrete girder section of the joint model was fully compressed. The maximum compressive stress of the top-plate concrete at the joint surface was -23.6 MPa， while the maximum tensile stress of the bottom-plate steel was 115.8 MPa. These values were much smaller than the design value of material strength. When under 1.4 times the load-bearing capacity limit state condition， the test model of the steel-concrete joint exhibited no marked damage during the static loading process. The load-displacement/strain curves of measuring points on each control section basically showed a linear relationship， and the structure was always in an elastic working state， indicating that the joint had sufficient safety reserves. The vertical deformation of each section of the steel-concrete joint had no sudden change along the longitudinal direction， indicating that the force transmission of the joint was smooth， which can ensure that the rigidity of the main girder was steadily transitioned from the concrete to the steel box girder section. The relevant research findings can provide a reference for the design and construction of such hybrid continuous girder bridges in the future.

Abstract:To study the mechanical properties of high-strength steel T-stubs considering additional axial force under fire conditions， a numerical analysis of high-strength steel T-stubs was conducted using the finite element analysis software ABAQUS. The initial stiffness， tensile capacity， and failure modes of high-strength steel T-stubs considering additional axial force under fire conditions were obtained. The numericalanalysis results are compared with the test results to verify the numerical model.Subsequently， a parametric study was performed using the validated finite element model to examine the mechanical properties of high-strength steel T-stubs under combined tension-shear loadings under fire. The parametric study shows that with the increase of shear-tension ratio， the load-bearing capacity of the bolts becomes crucial to bear the load of high-strength steel T-stubs under the combined action of tension and shear， and the tensile load-bearing capacity and the ultimate displacement of T-stubs decrease sharply. Finally， the relational expression of the tensile force and shear force of high-strength bolts under fire conditions was deduced based on the Code for design of steel structures. The result was compared to the results obtained from the finite element simulation and experiments. The comparison shows that the relationship expression has good applicability， and it can accurately predict the tensile bearing capacity of bolts under fire conditions.

Abstract:Considering the dynamic interaction among receivers， pedestrians， and the structure， a pedestrian-floor-receiver full-path interaction vibration model is established. The vibration serviceability of the lightweight floor is evaluated in the form of probability. The excessive vibration of the floor is controlled by elastic constraints. To demonstrate the effectiveness of the elastic constraints in mitigating excessive vibration of the floor， a comparison is made with the tuned mass dampers （TMD） control. The DQ-IQ method is used to solve the pedestrian-floor-receiver coupled vibration control equations. The CFS combined floor is used as the computational model to obtain the dynamic response of the floor mid-span and the receiver when the pedestrian walks on the floor at different step frequencies， and the control effects are compared when TMD and elastic constraints are used. The cumulative probability of the floor and the receiver satisfying the serviceability limits under these two control measures were calculated with the serviceability limits as the reference standard. The results show that for the lightweight floor，when the stiffness coefficient is 0.5 and 3， the serviceability probability of the floor increases from 13.57% to 86.98%， and the serviceability probability of the receiver increases from 11.75% to 79.86%， which greatly improves the serviceability probability. It can provide a reference for the selection of rotational stiffness of boundary conditions in design. When the stiffness coefficient is 2， the serviceability probability of the floor is 68.80%， while the serviceability probability of the receiver is only 57.97%， and the difference is 10.83%. The receiver is more likely to have serviceability problems than structures under the same conditions when considering human-induced vibration. Therefore， it is suggested to increase the peak acceleration of the receiver in the serviceability evaluation.

Abstract:Based on the multiple-tuning mechanism， a multiple single-sided pounding tuned mass damper （MSS-PTMD） with distributed pounding mass and pounding energy dissipation devices is proposed. The proposed damper has a multiple-tuning function so as to cover a wider control frequency domain and has better damping performance. Meanwhile， the huge tuned mass of conventional SS-PTMD can separate into several small ones to improve the feasibility of the pounding-type tuned mass damper in practical engineering. To further study the characteristics of MSS-PTMD， the motion equations of a single degree of freedom structure coupling MSS-PTMD are established. The optimal parameters of MSS-PTMD are obtained based on H∞ optimization criteria. The control performance of SS-PTMD and a double single-sided pounding tuned mass damper （DSS-PTMD） is simulated and compared. Finally， the effectiveness of DSS-PTMD is verified through experiments. The results show that increasing the number of tuning masses can effectively improve the damping bandwidth and performance of the MSS-PTMD. In the tuning and ±5% detuning cases， the MSS-PTMD has better control performance than SS-PTMD.

Abstract:To investigate the dynamic response and load transfer path of the isolated structure subjected to multi-direction coupled dynamic excitation， a 1∶4 scale model shaking table test of a three-story irregular plane RC frame isolated structure was conducted.The progressive collapse resistance under multi-direction coupled dynamic excitation was revealed by studying the acceleration response， displacement response， internal force response of the isolation bearing， and concrete and reinforcement strains of the damaged span beam of the structure.Then， the distribution laws of the internal force of the damaged span beam and the damage index of the isolated bearing were analyzed by OpenSees.The results show that under the coupled excitation of the vertical unbalanced load caused by sudden failure of a single isolated bearing and bidirectional horizontal earthquake， the vertical dynamic response at the failure point increases significantly， and the markedvertical deformation occurs.The dynamic effect caused by isolated bearing transient failure has an influence on the internal force of all remaining bearings.In particular，the impact on the neighboring bearing’s internal force is more visible.Vierendeel action and beam end bending moment resist the vertical unbalanced load generated by isolated bearing transient failure.The damage index of neighboring bearings is most affected by the isolated bearing transient failure. The dynamic response of the failure zone under the multi-directional dynamic coupling excitation is more pronounced than that under the vertical unbalanced load only， and the damage index distribution of the isolation layer is more discrete than that under earthquakes only.

Abstract:To explore efficient and reasonable connection forms of precast hollow shear walls with boundary columns， and to address the challenges of connection construction and quality inspection， three horizontal seamconnections （boundary column connection by vertical additional steel bars， indirect lapping connection of U-shaped steel bars， and steel joint connection） were proposed. Quasi-static tests were carried out on three hollow shear walls with precast boundary columns， along with a cast-in-place hollow shear wall， to study the seismic and working performance of these connections. The results showed that the specimens exhibited a compression-bending failure mode，successfully achieving the expected “strong shear weak bending” behavior. The ductility coefficient of precast specimens was around 4. Compared with the cast-in-suit specimen， the energy dissipation capacity and deformation capacity of each precast specimen were slightly weaker. The limit drift ratio of the precast specimen was between 1/56 and 1/67， and the elastic-plastic deformation capacity met the requirements of the current code. Through-cracks were easy to form at the horizontal seam， but the horizontal shear configuration can meet the code requirements. The applicability of calculating the bearing capacity of the specimen based on the code was analyzed， and a calculation method considering the influence of horizontal seam was proposed.

Abstract:For eccentric high-rise buildings with non-coincident centers of mass and rigidity， evaluating the three-dimensional （3D） wind induced effect and the equivalent static wind loads （ESWLs） becomes complicated due to the influence of the 3D mode coupling and aerodynamic coupling of the structure. This paper derives a group of equations based on the mode acceleration method. These equations enable calculating the quasi-static and inertial part of internal force （shear and moment） responses for each floor of eccentric rectangular high-rise buildings， considering the effects of coupling vibration modes and cross-correlations between modal responses. On this basis， evaluation methods for 3D internal force ESWLs along the height distribution are derived. Finally， analyses are conducted to examine the effects of load correlation， structural eccentricity ratio， and aspect ratio on ESWLs combined with three kinds of high-rise building pressure tests. The research results show that for eccentric high-rise buildings， the contribution of mode coupling and load correlation to the structural wind-induced response and ESWLs cannot be ignored. If these two parts are ignored， the three-dimensional equivalent wind load of eccentric high-rise buildings， especially the torsional equivalent wind load， will be underestimated. In addition， different eccentricity ratios and aspect ratios have an impact on the magnitude and distribution of the ESWL for eccentric high-rise buildings. The relevant conclusions can provide guidance for the wind resistance design of eccentric high-rise buildings.

Abstract:The wind tunnel test method is employed to study the wind pressure characteristic of the canopy affiliated with high-rise buildings. The variation of wind pressure coefficient， wind pressure correlation， non-Gaussian， and overall lift coefficient with the wind direction angle is analyzed. The design wind loadings on the building envelope are also given. Finally， the influence of tilt angle and cantilevered length on the overall lift coefficient is investigated. Studies show that the maximum wind pressure coefficients of the upper surface of the canopy affiliated with the building reach almost 1.4 in the wind-facing direction， which can be attributed to the fact that the airflow is blocked by the high-rise building and then turned down on the canopy. The overall press coefficients of the upper and lower surface reach their maximum values in the wind-facing direction， and the coefficients are 1.24 and 0.76， respectively. The overall lift coefficients on the upper and lower surface reach their maximum values at the side direction， and their values are 1.13 and 1.01， respectively. After being superimposed on the upper and lower surface， the pressure presents a higher non-Gaussian distribution property than those on each surface. The lift coefficients of the upper and lower surfaces show a Gaussian distribution in the wind direction of 0°~70° and a non-Gaussian distribution in the wind direction of 80°~180°. The positive extreme wind pressure coefficient on the upper surface of the canopy affiliated with the building is higher than that on the lower surface. The overall lift coefficients of the canopy increase in sequence with the attack angle of -10°， 0°， and 10°.

Abstract:Wind tunnel tests were carried out to study the wind load characteristics of flat uniaxial photovoltaic panels with large aspect ratios. The most unfavorable incoming wind direction of photovoltaic panels， effects of inclination angle， the wind load distributions of the isolated model， and the array models are analyzed， respectively， considering the arrangement form of the single cell and the array， seven kinds of photovoltaic panel inclination angles from 0° to 60°， and seven incoming wind directions. The interference effect on wind loads for array arrangement is discussed. The test results are compared with the wind resistance codes of four countries， and the recommended values of the wind force coefficient are given. The study found that 0° and 180° are the most unfavorable wind directions for photovoltaic panels and overturning bending moment. The overturning bending moment coefficient around the rotating axis， the overall wind force coefficient， and the distribution and magnitudes of the local wind force coefficient are affected by the inclination angle of the photovoltaic panel and the direction of the incoming wind. For the overturning bending moment coefficient around the rotating axis， the flat uniaxial photovoltaic panel with a small inclination angle has larger values compared with the flat uniaxial photovoltaic panel with a large inclination angle. For the entire wind force of the photovoltaic panel， the flat uniaxial photovoltaic panel with a large inclination angle is more severe. The local wind force coefficient distribution presents a gradient change， the largest local wind load is found on the windward corner， which changes dramatically due to airflow separation.

Abstract:To understand the influence of the railing heights on the vortex-induced vibration （VIV） performance of the girder， and to reveal its mechanism， a segment model wind tunnel test including dynamic pressure and vibration measurement was carried out. The VIV response， aerodynamic forces， mean and fluctuating wind pressure coefficients， frequency domain characteristics， and the distribution of contribution coefficient of local lift on VIV were comprehensively analyzed. The results indicate that after installing the railings， the mean wind pressure coefficient is increased， and the fluctuating wind pressure change is complicated. The predominant frequency of fluctuating wind pressure is almost consistent with the natural frequency of the model. And the contribution function of the local lift on VIV increases. Therefore， the VIV phenomenon is far more marked. And the influence of variation in railing height on the surface wind pressure coefficient of the girder is negligible， but it has a great influence on the distribution of fluctuating wind pressure coefficient and the amplitude of fluctuating pressure power spectrum； with different railing heights， local lift in the front and tail areas of the upper surface of the main beam contribute differently to the vortex. When the contribution increases， the VIV response of the main beam increases； when the railing height is 45% of times the beam height， the vortex response of the streamlined box girder is the largest. On this basis， appropriately reducing or increasing the railing height has a certain vibration suppression effect， and especially reducing the railing height shows a better effect. The research results provide a basis and reference for the design and related research of streamlined box girder railings.

Abstract:To study the response of the CAARC standard high-rise building model under a downburst， firstly， a downburst outflow wind speed simulation test device based on a boundary layer wind tunnel was developed. The steady-state wind field and transient wind field of the downburst were simulated in the boundary layer wind tunnel， respectively. Then， a CAARC aero-elastic model with a geometric scale 1∶200 was designed and made. Finally， the wind tunnel tests of the CAARC standard high-rise building model were carried out under the downburst steady， transient wind， and type B atmospheric boundary layer wind field， respectively. The results show that the experimented steady-state wind speed profile of downburst outflow fits well with the empirical wind speed profiles. Furthermore， the characteristics of simulated downburst transient wind speeds and turbulence intensities are generally consistent with the recommended values from the existing research. Under the action of downburst steady-state and transient wind fields， the displacement time history at the top along the x and y directions fluctuate greatly， which is significantly different from that of the type B atmospheric boundary layer wind field.

Abstract:In traditional offshore wind turbine model tests， it is difficult to reproduce the turbulent wind loads in the laboratory. And the space limitation of the laboratory site makes it impossible to carry out large-scale offshore wind turbine model tests. The scale contradiction between the upper wind turbine and the lower platform cannot deeply study the full coupling mechanism of the offshore wind turbine. With the improvement of computing power and the breakthrough of key problems such as numerical integration algorithm and control， the above contradiction can be solved by the real-time hybrid test method. This paper takes the 5 MW fixed offshore wind turbine of the National Renewable Energy Laboratory （NREL） as the research object and makes the physical substructure model according to the scale of 1∶90. AeroDyn program is developed as the numerical substructure， UDP / IP communication mechanism is added as the data acquisition and transmission mode， and the push rod actuator is taken as the loading device to build a complete real-time hybrid test system so as to carry out the real-time hybrid model test of fixed offshore wind turbine under no wave condition. The test results are compared with these of FAST software. The good agreement shows the feasibility of the real-time hybrid model test method， which provides a reference for the further development of the real-time hybrid model test technology of offshore wind turbines， and provides technical support for the structural design and safe operation of the offshore wind

Abstract:Aiming at the problems of high fire hazard and low levels of intelligent fire monitoring in the historic buildings of Ming and Qing Dynasties， this article takes xBIM as the secondary development platform， establishes a database using SQL Server， and builds an intelligent fire monitoring platform， so as to realize the integrated management of the monitoring system of the huge ancient buildings. For the real-time data generated by the detector， the iterative optimization of the Mann-Kendall trend algorithm not only effectively avoids the drift problem caused by the traditional fixed threshold algorithm， but also improves the accuracy of the fire detectors. Combining the fire dynamics simulation and taking the fire hazard source and the building structure as the influencing factors， the layout of the fire detector is reasonably optimized to improve the efficiency of its detection. This article provides a set of scientific and efficient integrated management technology for the fire supervision of historic buildings in the Ming and Qing Dynasties.

Abstract:Based on the classical one-dimensional particle migration model， a three-dimensional particle migration model with a double deposition model was established， which considered both the sieve effect and the adsorption effect. Using Laplace and Fourier transforms the general solution of particle migration in saturated semi-infinite porous media under one-dimensional seepage and three-dimensional dispersion conditions is derived. According to the basic solution of point source injection on a semi-infinite body surface， the analytical expression of circular surface source injection is obtained by the integral method. The correctness of the understanding is verified by the degradation of the solution and the parameter inversion of the breakout curve. The influence mechanism of the hydrodynamic dispersion coefficient， sieve coefficient， particle adsorption coefficient， and particle desorption coefficient on the particle migration process was analyzed under constant concentration injection of the circular surface source. The results show that the hydrodynamic dispersion effect accelerates the migration of particles， making the breakthrough time faster and the peak concentration higher. The larger the sieving coefficient and particle adsorption coefficient， the smaller the particle release coefficient， the more particles deposited on the solid matrix， and the smaller the peak particle concentration in the pore. In the case of constant concentration injection of circular surface source， the concentration of particles in porous media increases with time and decreases with depth， and tends to 0 during particle injection. After particle injection is stopped， the concentration of particles in the porous media decreases with time， and there is a concentration peak in depth. The depth of the concentration peak increases with time.

Abstract:Nonlinearity is an inherent property of geo-materials. Under this property condition， the potential sliding surface of a homogeneous slope based on the rotational failure mechanism is not a single log-spiral under the nonlinear failure criterion. Therefore， the geo-materials of the slope are assumed to obey the three-parameter nonlinear strength criterion， and the rotational failure mechanism of the homogeneous slope was constructed based on the upper bound theorem of limit analysis. The seismic load was introduced through a pseudo-static method， and the differential equations of the critical sliding surface and its corresponding stress distribution of homogeneous slope were obtained according to the mechanical equilibrium equations and the variational principle. And then the equations were solved by the Runge-Kutta method. According to the virtual power principle， the minimum critical height of the slope was optimized through Immune Algorithm （IA）. The accuracy and validity of the nonlinear upper bound variation analysis method were verified by comparing it with the results of finite element limit analysis （FELA）. On this basis， the effects of dimensionless strength parameters （T， A， n）， the horizontal seismic acceleration coefficient （kx）， and slope angle （β） on the slope stability factor Fn， potential sliding surface， and its stress distribution were analyzed. There is no need to assume the potential sliding surface of the slope， and this work enriches the nonlinear analysis theory of slope stability and provides theoretical support and useful reference for slope reinforcement design.

Abstract:Aiming at the asymmetric distribution of defects in the pile shaft of large-diameter pile foundation， employing the numerical simulation method， three-dimensional finite element pile-soil models are established for analyzing the dynamic responses of the pile. The different influence laws of symmetrical defects and asymmetric defects on the dynamic responses at the pile top are studied. The rationality of the numerical models is verified by comparing the simulated results with the test ones. In addition， the sensitivity analysis is conducted to study the effects of the parameters， such as soil around the pile and the excitation width and defect shape， on the dynamic responses of asymmetric defect piles. The results show that the dynamic response at the pile top of the symmetrical measuring points presents a double closed-loop phenomenon when asymmetric defects exist. The symmetrical measuring point with the most obvious double closed-loop phenomenon is located on the symmetry axis of the defect section. The mode of central excitation on the pile top and synchronous receiving of the symmetrical points can be used to detect the asymmetric defects of the piles， which can guide the engineering application of the low-strain integrity testing.

Abstract:Energy piles are subject to a combination of mechanical and thermal loads during the normal service process， and their load transfer characteristics will be changed， but the existing theoretical methods for the bearing characteristics of energy piles are not yet complete enough. To study the working characteristics of single energy piles under coupled thermo-mechanical loading， the analysis method of single energy piles under coupled thermo-mechanical loading based on the load transfer method and energy balance principle is proposed by considering the effect of temperature on the load transfer function. The research results show that the thermal load affects the axial force and shaft resistance change laws， and the pile-top settlement values under different pile-top load levels are analyzed. Under the mechanical load and heating/cooling condition， when the pile-top load level is low （≤25%Pu， wherePu is the ultimate load）， the effect of temperature change on the pile-top settlement amplitude is significant， and the pile top settlement amplitude can reach 55% （25%Pu）； especially in the mechanical load and cooling condition， when the pile-top load level exceeds 75%Pu， the pile-top settlement value is close to the limit value， and special attention should be paid to the bearing performance of the pile foundation at this time.

Abstract:The online monitoring of water quality still has the problems of a single indicator， unstable results， and low reliability. In this paper， the construction effectiveness evaluation of a sponge city road is conducted with water analysis in manual sampling， combined with the methods of flow monitoring and SWMM modeling. The result shows that the sponge road has significant effects on total runoff control， runoff pollution control， drainage， and water-logging prevention. In a typical year with average precipitation， the annual total-runoff-control rate of the sponge road reaches 94.2%. The runoff-pollution-reduction rates are 88.5% （calculated by SS）， 88.3% （calculated by COD）， 86.7% （calculated by TP）， and 88.5% （calculated by NH3-N）， respectively. And the peak-runoff-reduction rate of stormwater with a 20-year return period reaches 75.2%. This research provides a reference for the examination and assessment of the construction effectiveness of sponge roads.

Abstract:To address the stochastic discrete time-cost trade-off problems in construction projects， a double loop optimization procedure， which utilizes Genetic algorithm and monte Carlo simulation respectively in the outer and inner loops， is usually implemented. To reduce computational resources in the inner loop， an effective and dynamic strategy for allocating computational resources is proposed based on the statistical properties of the Monte Carlo simulation estimator. As shown by an illustrative example， the improved optimization algorithm can efficiently and stably solve the stochastic discrete time-cost trade-off problems in construction projects.