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Slope failure during or immediately after slope-cutting can cause fatal accidents. This study analyses the characteristics of labour accidents caused by slope failure during slope-cutting in Japan and presents a countermeasure to prevent accidents caused by slope failure, such as the implementation of a slope guideline by MHLW. A case history conducted during slope-cutting and nailing was presented as an example of the application of the slope guideline to ensure safety. Furthermore, monitoring methods were implemented to gain a quantitative understanding of slope deformation. Geological conditions other than those assumed prior to excavation and small collapses attributed to groundwater are indications of landslide risk. The guideline's quick checklist reflects the slope condition or deformation, allowing the client, designer and contractor to discuss and agree on a quick solution to a problem. The case study confirmed the effectiveness of the slope guideline as a tool for sharing information during construction. [ABSTRACT FROM AUTHOR]

[Objective] To study the vibration characteristics of subway stations caused by the entry and exit of three-line parallel subway stations. [Method] Taking a third-line parallel transfer subway station in a domestic city as the research object, the vibration characteristics and propagation rules of the station were analyzed based on the field measured data. [Results] Affected by the completion and operation of the line, the vibration response of each platform in the station varied greatly. Under the inbound condition, the average Z vibration levels of platforms 1,2 and C were 81.9,91.4, 61.7 dB, and the main frequency bands of platform 1 and 2 were 75~125 Hz. Under outbound conditions, the average Z vibration levels of the three platforms were 82.7,93.8, 63.7 dB, the main frequency band of vibration of platforms 1 and 2 is 50~100 Hz, while the vibration response of platform C is concentrated within 50~60 Hz under both conditions. [Conclusion] In most measuring points in the station, it can be found that the vibration under outbound conditions is greater than that under inbound conditions, and the maximum difference is about 2.5 dB. After the vehicle-induced vibration is transmitted to the ground floor, it will first produce a certain attenuation, and when it is transmitted to the ground floor, it will produce amplification, and the vibration is about 3.6~5 dB. The attenuation of vehicle-induced vibration transmitted in the station building is small, and the vibration attenuation mainly depends on the soil layer, and the vibration attenuation is about 0.53 dB/m. The research results can provide a reference for vibration prediction, vibration comfort evaluation and vibration reduction design of similar structures, subway stations and buildings with parallel access to multiple lines. [ABSTRACT FROM AUTHOR]

A significant proportion of the world's population is currently experiencing heat stress. This results from the effects of global warming, urban heat islands (UHIs), and the growth of urban populations. Researchers have investigated multiple strategies to address this problem. It has been found that the outdoor thermal environment (OTE) can be modified by means of vegetation, water surfaces, and urban geometry. Several studies have indicated that certain geometric factors have demonstrated a higher degree of effectiveness in cooling the surrounding environment. OTE studies often employ two commonly utilised factors, known as urban geometry indicating parameters (UGPs)—the sky view factor (SVF) and height-to-width ratio (H/W). This article compares OTE studies focusing on these two factors. The comparison encompasses characteristics such as study methods, places and times of conducting, and thermal indices. The findings indicate that geometric studies have primarily relied on simulation and field measurement methods. These studies were predominantly conducted in tropical or subtropical cities during warm seasons, with a preference for daytime investigations. Complex thermal indices, including the physiologically equivalent temperature and mean radiant temperature, were commonly employed. In addition to UGPs, other physical factors, such as orientation, were also taken into consideration. Studies on H/W and SVF differed slightly although they are both geometrically indicative. This review can provide guidance for future studies in the field of urban geometry, in that researchers may choose to prioritise the examination of practical indicators, such as the energy load, to conduct a more comprehensive analysis while also taking into account other physical aspects, such as the presence of trees.

Abstract This study investigates the deformation and damage characteristics of the surrounding rock along the top return mining roadway of an isolated island working face at different stages and reveals its damage mechanism and evolution law. Utilizing a mine in Yangquan City, Shanxi Province, China, as the engineering background, this research employs FLAC 3D numerical simulation and on-site measurements. The findings suggest that the evolution of the plastic zone along the top roadway of the 15,106 island face is largely similar during both the excavation and mining periods. The plastic zones on either side of the roadway are expanding asymmetrically and gradually merging into the plastic zone of the coal pillar. In the destructive stage, the sub-gangs of the roadway are penetrated, indicating the progression into the plastic zone. The investigation points to extensive damage on the larger side of the roadway, the development of fissures, and the significant depth of damage as primary causes of roadway deformation. Moreover, the extent of the plastic zones on both sides of the roadway correlates positively with their relative distance. Continuous monitoring reveals an ongoing increase in roadway displacement, consistent with general observations in coal mining. The results provide valuable insights for optimizing support structures in similar mining environments.

Geological structures significantly influence mining-induced deformations in open-pit mines, with their variations and interactions adding complexity to the excavation process and introducing uncertainties in deformation outcomes. This study utilized numerical simulations to analyze the impact of weak rock zones in a specific open-pit limestone quarry in Japan on mining-induced deformation. The simulation results were both qualitatively and quantitatively validated against field measurements, enhancing the reliability of the findings. Subsequently, four conceptual models were developed based on the characteristics of the quarry to investigate the mechanisms by which weak rock zones affect rock slope deformations. Our analyses demonstrated that slip deformation occurred exclusively when two weak rock zones were connected. This deformation was associated not only with shear failure in the upper weak rock zone but also with the contraction and bending of the lower weak rock zone. Furthermore, the simulation results were consistent with field data and supported by the conceptual models, confirming that the proposed sliding mechanisms can effectively explain the observed deformation behaviors. The insights gained from these models provide valuable references for managing similar geological challenges in other open-pit mines. [ABSTRACT FROM AUTHOR]

This study investigates the deformation and damage characteristics of the surrounding rock along the top return mining roadway of an isolated island working face at different stages and reveals its damage mechanism and evolution law. Utilizing a mine in Yangquan City, Shanxi Province, China, as the engineering background, this research employs FLAC 3D numerical simulation and on-site measurements. The findings suggest that the evolution of the plastic zone along the top roadway of the 15,106 island face is largely similar during both the excavation and mining periods. The plastic zones on either side of the roadway are expanding asymmetrically and gradually merging into the plastic zone of the coal pillar. In the destructive stage, the sub-gangs of the roadway are penetrated, indicating the progression into the plastic zone. The investigation points to extensive damage on the larger side of the roadway, the development of fissures, and the significant depth of damage as primary causes of roadway deformation. Moreover, the extent of the plastic zones on both sides of the roadway correlates positively with their relative distance. Continuous monitoring reveals an ongoing increase in roadway displacement, consistent with general observations in coal mining. The results provide valuable insights for optimizing support structures in similar mining environments. [ABSTRACT FROM AUTHOR]

Unsaturated soil contains pore air, some of which becomes entrapped in the soil layer during the infiltration process. Such entrapped pore air in the soil layer inhibits infiltration, decreases hydraulic conductivity, and causes erroneous estimates of groundwater response. Experimental studies suggest an effect of compressed entrapped pore air on stream discharge. However, few studies have investigated the behaviour of pore air in the field, and no method for measurement of pore‐air behaviour has been established. We measured pore‐air pressure (Pair) with a simple handmade probe, combined with atmospheric pressure (Patm) and groundwater level. The entrapment and compression of pore air were detected based on the pressure difference (ΔP = Pair – Patm). Observations were conducted for approximately 1 year in two small headwater catchments (TC and HA, which have differences in soil depth and groundwater level dynamics) in Ibaraki Prefecture, Japan. Positive responses of ΔP during some rainfall events were confirmed at both TC and HA. Pore‐air entrapment occurred even during weak rainfall events with rainfall intensity of <10 mm/h. During a typhoon event in October 2019, a maximum ΔP of 3.9 kPa was observed at HA. The pore pressure increase recorded by the tensiometer was mostly explained by the increase in ΔP, which was supported by the soil moisture data. Therefore, we concluded that our handmade measurement system could successfully measure Pair and detect pore‐air entrapment in the field. This showed that Pair is not negligible. Total event rainfall was related to the maximum ΔP. It also showed that the rise in the groundwater level plays a significant role in pressurization of the entrapped pore air. We present the first field data demonstrating the effect of groundwater level rise on the pressurization of entrapped Pair. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Southeast University / Dongnan Daxue Xuebao is the property of Journal of Southeast University Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Engineering Mechanics / Gongcheng Lixue is the property of Engineering Mechanics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Summary: In operational modal analysis (OMA), only structural responses are typically available. In this context, bias and variance (uncertainty) errors may exist in modal estimates (especially damping estimates), resulting in inaccurate determination of the modal properties of large‐scale structures under harsh excitations. To this end, a hybrid OMA framework based on the modal decoupling, the natural excitation technique, the random decrement technique (RDT), and improved eigensystem realization algorithm (ERA) with the automated stabilization diagram is presented to perform high‐accuracy modal estimates with uncertainty quantification for large‐scale structures under normal and severe ambient excitations. The accuracy and effectiveness of the hybrid framework for identifying the modal parameters are validated by numerical simulation study of a framework structural model. Furthermore, the hybrid framework is applied to analyze recorded acceleration responses of a supertall building with 600‐m height under normal excitations and typhoon condition to verify its applicability in field measurements. The numerical simulation and field measurement studies demonstrate that the hybrid framework can not only perform precise modal estimations with uncertainty quantification through a single ambient vibration measurement but also effectively reveal the variations of modal properties of supertall structures under harsh excitations from multiple perspectives. This paper aims to enhance the reliability and accuracy of modal estimation for engineering structures and further provide insight into the variations of dynamic properties of large‐scale civil structures under severe excitations. [ABSTRACT FROM AUTHOR]

This paper presents measurements of total pressures and pore pressures in the mixing chamber, the pore pressures in the soil in front of an earth pressure balance (EPB) at the Botlek Rail tunnel, as well as laboratory tests on foam infiltration behavior from foam–sand mixture to saturated sand. It shows that the plastering effect at the tunnel face is less effective for an EPB shield than for a slurry shield, as the pressure fluctuations are greater in the mixing chamber for an EPB shield, suggesting a higher water leakage at the tunnel face. The difference in the development of excess pore pressure at two different locations of the EPB shield suggests the influence of the soil permeability. Foam infiltration at the tunnel face can result in a low permeable layer that restricts the ground water flow. Results from laboratory tests suggest that foam infiltration will be influenced by foam injection ratio and soil permeability. As the foam infiltration length is only limited, no low permeable layer can be formed during drilling for fine sand conditions. While a larger foam infiltration length can be expected for medium sand condition. Field measurements on the development of pore pressures in the soils at the two different locations show agreement with the conclusions from laboratory tests. [ABSTRACT FROM AUTHOR]

Copyright of Railway Standard Design is the property of Railway Standard Design Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Ground Improvement is the property of Journal of Ground Improvement Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

The high-speed maglev vehicle/guideway coupled model is an essential simulation tool for investigating vehicle dynamics and mitigating coupled vibration. To improve its accuracy efficiently, this study investigated a hierarchical model updating method integrated with field measurements. First, a high-speed maglev vehicle/guideway coupled model, taking into account the real effect of guideway material properties and elastic restraint of bearings, was developed by integrating the finite element method, multi-body dynamics, and electromagnetic levitation control. Subsequently, simultaneous in-site measurements of the vehicle/guideway were conducted on a high-speed maglev test line to analyze the system response and structural modal parameters. During the hierarchical updating, an Elman neural network with the optimal Latin hypercube sampling method was used to substitute the FE guideway model, thus improving the computational efficiency. The multi-objective particle swarm optimization algorithm with the gray relational projection method was applied to hierarchically update the parameters of the guideway layer and magnetic force layer based on the measured modal parameters and the electromagnet vibration, respectively. Finally, the updated coupled model was compared with the field measurements, and the results demonstrated the model's accuracy in simulating the actual dynamic response, validating the effectiveness of the updating method. [ABSTRACT FROM AUTHOR]

In particular, the secondary development of overlying strata fractures can easily lead to the upper goaf, resulting in gas and water gathered in the goaf entering the working face of the lower coal seam through the overlying strata fractures, threatening the safety of coal mine production. Security risks may arise. To further understand the caving and evolution law of overlying strata during repeated mining in extremely close distance coal seam down mining, 9# coal and 10# coal in the Nanyaotou Coal Industry were used as the engineering background. The caving characteristics and fracture evolution law of overlying strata during single and repeated mining were analyzed through similar material simulation tests. Based on fractal geometry theory, the relationship between the advancing distance of the working face and the fractal dimension of the overlying strata fracture is established to reflect the changing trend of fracture development. The calculation formula is derived from the tensile rate of rock strata to predict the development height of water-conducting fractures. The results show that the overlying strata failure structure is mainly a “hinged structure” and a “step structure,” which respectively promotes and inhibits the development of overlying strata fractures. Repeated mining causes mining-induced fractures in the lower coal seam to pass through the goaf of the upper coal seam and develop more vigorously in the upper coal seam, and the fractal dimension can effectively reflect the development of overlying strata fractures. The height of the water-conducting fracture zone increases in four stages: incubation, gradual increase, further gradual increase, and stability, eventually stopping development under the influence of the key layer (thick mudstone) bearing the load above. The development height of water-conducting fractures predicted by on-site water injection measurement is similar to that predicted by simulation experiments and theoretical calculations, verifying the feasibility of predicting the development height of water-conducting fractures through simulation tests and theoretical analysis. This study provides a reference for coal seam mining under similar conditions.

Cleanrooms are critical in the semiconductor industry, particularly for optical fabrication, where even minor contamination can compromise product quality. Effective airflow and uniform airflow distribution help to prevent contaminant accumulation, mitigate temperature variations, and avoid cross-contamination, which is crucial for achieving high-quality results and compliance with industry standards. This study introduces a novel approach to optimizing Fan Filter Unit (FFU) configurations to enhance thermal performance and contaminant removal in cleanroom settings. Integrating field measurements with advanced Computational Fluid Dynamics (CFD) simulations to comprehensively evaluate four distinct FFU designs, from dispersed to centralized configurations, focused on their impact on airflow dynamics, temperature uniformity, and particle concentration. The study identifies a significant advancement in FFU configuration by demonstrating that centralized arrangements (Designs 2 and 4) substantially improve cleanroom performance. Design 4 emerged as the most effective, showcasing a marked improvement in airflow circulation, a 12 % reduction in temperature variation, and a 15 % decrease in particle concentration compared to conventional designs. This achievement underscores the novel contribution of this study in optimizing FFU configurations to enhance both thermal performance and contaminant control. These findings not only advance the theoretical understanding of FFU design but also provide practical insights for improving cleanroom environments. The study offers a significant step forward in developing efficient cleanroom designs, contributing valuable guidelines for achieving good environmental control in sensitive manufacturing processes.

Residential biomass burning significantly contributes to air pollution in developing countries. However, the microscopic properties of individual particles in their emissions have not been well understood. In this study, individual primary particles from 14 kinds of biomass fuels (including firewood, crop residue, and animal dung) were collected in laboratory and field measurements, and their morphology, composition and mixing state were acquired using transmission electron microscope. These results constitute a source profile database of individual primary particles from residential biomass burning. The database reveals that different types of biomass fuels exhibit different emission characteristics, that is, residential firewood burning mainly emits pure carbonaceous particles (including organic matter (OM) and soot particles), crop residue burning mainly emits K‐containing particles (including OM‐K, soot(‐OM)‐K, and K‐rich particles), and animal dung burning mainly emits pure carbonaceous particles and K‐containing particles. Moreover, our results indicate that the emission characteristics obtained from laboratory and field measurements are different. Field measurements conducted in two selected villages in North China Plain exhibit a higher presence of soot particles compared to laboratory measurements, owing to their higher combustion temperatures. In contrast, field measurements conducted in one selected village in Qinghai‐Tibet Plateau contain less soot particles than those from laboratory measurements in plain areas, due to the deficient oxygen supply during combustion process in the high‐altitude regions. These results warn us that the emission estimation from residential biomass burning should notice the large emission differences among different biomass types and between field and laboratory measurements. Plain Language Summary: Biomass fuel is an important household energy for cooking and heating in the rural regions in developing countries. However, biomass fuel burned in the residential stoves can emit large amount of air pollutants, which could adversely influence air quality, human health, and global climate. To investigate these adverse effects, understanding the microscopic properties of individual primary particles from residential biomass burning is the crucial step, but there is limited information on these microscopic properties. To fill the gaps, we acquired the morphology, composition, and mixing state of individual particles from firewood, crop residue, and animal dung burning using field and laboratory measurements. We found these three types of biomass fuels exhibit obviously different emission characteristics, and emissions from laboratory and field measurements are also different. Moreover, we found that compared to the laboratory biomass burning, field biomass burning conducted in the selected villages in the low‐altitude regions can emit more soot particles, while it in the high‐altitude regions can emit more organic matters but less soot particles. These emission differences warn us that more field measurements in different regions should be investigated in the future studies. Key Points: A source profile database of individual primary particles from residential biomass burning was establishedDifferent types of biomass fuels exhibit distinctly different emission characteristicsEmission characteristics of field and laboratory residential biomass burning are different [ABSTRACT FROM AUTHOR]

The safety of the geotechnical environment around subways is vitally important for their sustainability. Ground settlement is a very common threat to the safe operation of subways and is related to subway traffic vibrations. Taking Nanjing subway line 10 as an example, field tests, discrete element simulations, and a grey relational analysis are carried out to study the deformation mechanism of the underlying sandy soil induced by vibrations. The results show that the vibration load of Nanjing subway Line 10 is mainly concentrated in the vertical direction. The particles' coordination number below the subway increases under the vibration load, while the coordination number on the side of the tunnel decreases, which may cause a shear dilatancy effect. Among the five microscopic indexes, the local porosity and the coordination number are closely related to the deformation. Although the deformation of the underlying sandy soil is quite small under the subway traffic load, it will accumulate under frequent loading and then lead to urban engineering geological disasters. [ABSTRACT FROM AUTHOR]

Short-span bridges are one of the most frequent infrastructures along railway tracks where railway track stiffness suddenly changes. The sudden variation in the vertical stiffness of railway tracks increases dynamic loads and causes numerous defects in ballasted railroads. Therefore, improving the dynamic performance of railway tracks can be conducted by constructing countermeasures along the transition zone. In this regard, the approach slab is a practical technique used in railway-bridge transition zones. As the dimensional shape of the approach slab plays a significant role in the dynamic response of transition zones, this study evaluated the effects of its main geometric parameters. A three-dimensional model of the railway portal bridge, including the approach slab, was built using the finite element method and analyzed by imposing moving wheel loads as a series of acting force points along rail elements. The model was validated with field-obtained results acquired through a laser/camera-based measuring technique. Then, some sensitivity analyses were performed to find optimized geometric dimensions of approach slabs to improve the dynamic behavior of railway-bridge transition zones. Obtained results of the geometrical sensitivity analysis show that when the geometrically optimized approach slab is used along the railway-bridge transition zone, the displacements of rail and ballast are decreased by 24% and 18%, respectively. [ABSTRACT FROM AUTHOR]

This paper examines the engineering background of the main shaft of Ruihai Mining Group Company in Laizhou City, with a focus on the loose permeable stratum located in the frozen section of the shaft. Field measurements and data collection, including brine temperature and surface subsidence values, were conducted using temperature and hydrological boreholes. The distribution of the frozen wall temperature field was then numerically simulated using finite element analysis, and the results were compared and analyzed with field data. Scanning electron microscopy (SEM) was used to qualitatively describe the microstructure of the soft rock in the frozen section under different freezing schemes. Based on the formation of the frozen wall, a new construction scheme for freezing and excavating the internal and external circles of the vertical shaft in the loose permeable stratum is proposed. This involves the implementation of "inner and outer double-circles of freezing holes" and a comparison of the freezing effect of the temperature field before and after the improvement. The results indicate that the new freezing scheme can accelerate the freezing rate of the surrounding rock of the shaft, and reduce the time required for closure by more than 10 days. After applying the improved scheme for 60 days, the temperature is lowered by 4–5 ℃ compared to the original scheme, and the thickness of the frozen wall is approximately 4.8 m, significantly thicker than before. These findings demonstrate the effectiveness of adding an inner circle of freezing holes in achieving the lowest temperature which contributes to subsequent shaft excavation. The new scheme holds significant implications for the safe construction of shaft excavation in complex hydrogeological areas. Highlights: The main shaft in the unique geological conditions and the impact of tidal activities on freezing performance are analyzed. The new construction scheme incorporating "inner and outer double-circles of freezing holes" significantly improves freezing efficiency and reduces closure time. The improved scheme results in a thicker frozen wall and lower temperature compared to the original scheme. The findings have important implications for the safe construction of shaft excavation in complex coastal hydrogeological areas. [ABSTRACT FROM AUTHOR]

In urban areas where populations commonly reside, particle mass concentrations in street canyons can pose significant risks to human health. This study aimed to investigate the diffusion mechanism of particle mass concentrations in urban street canyons by developing and applying a prediction model based on the mathematical modeling of physical processes. The prediction model considered factors such as the influence of traffic wind, natural wind, traffic flow, and other relevant variables influencing particle mass concentrations in street canyons. Field measurements were conducted in Dalian, China, to verify the feasibility of the model. Particle mass concentrations, traffic flow, temperature, relative humidity, and wind speed were measured on Shichang Street (a two-lane one-way road), Tangshan Street (a four-lane two-way road), and Shengli Road (a six-lane two-way road). The results indicated that the majority of traffic peaks occurred around 19:00 on all road types. The PM1.0 mass concentration was well diluted on the four-lane two-way road, with the least dilution observed on the two-lane one-way road. A strong correlation between the particle mass concentrations and traffic flow was discovered. Furthermore, a prediction model was established, accurately predicting the particle mass concentrations when the prediction step was from 5 to 15 s. The coefficient of determination (R2) between the predicted and measured values on the two-lane one-way road, four-lane two-way road, and six-lane two-way road was 0.9319, 0.6582, and 0.9238, respectively. Additionally, the prediction model allowed for a detailed analysis of traffic flow limitations, corresponding to the recommended World Health Organization (WHO) PM2.5 values. Overall, the findings of this study offer valuable insights for forecasting particle exposure levels in street canyons. [ABSTRACT FROM AUTHOR]

To reduce the low-order vibrations of high-voltage transmission towers in response to strong winds, a tuned mass damper (TMD) that uses eddy current damping (ECD) with omnidirectional damping function (ECD-TMD) is proposed here. Compared with previous similar devices, the outstanding advantage of the proposed ECD-TMD lies in its use of non-contact ECD, structural simplicity, lack of internal friction, ability to sense micro-vibrations, and in the asymmetric cantilever pendulum structure that enables omnidirectional vibration suppression. Aero-elastic model wind tunnel test and field measurements were used for analyzing and validating the vibration responses of a 50-m-tall transmission tower with and without the proposed ECD-TMD. The results demonstrated that the proposed ECD-TMD reduced transmission tower's first-order bending vibrations along and across the direction of transmission line. For the mass ratio of approximately 2%, approximately 18–27% reduction of acceleration and 10–25% reduction of displacement occurred. Because the first-order resonance of the tower body in response to wind accounts for a small fraction of the background response, the addition of a TMD device suppresses structural wind vibrations in a limiter manner but can significantly increase the first-order bending damping ratio of the tower. [ABSTRACT FROM AUTHOR]

To solve the technical problems of safe and efficient exploitation of coal resources by abandoned oil wells in the Ordos Basin, several characteristics of the coal seam need to be fully explored: petroleum seepage pressure, seepage velocity and seepage range. However, these are difficult to determine in situ, and often numerical models are used. A comprehensive analysis method combining COMSOL Multiphysics numerical software and seepage model is proposed here based on the continuous non-linear theory of seepage flow and the constructed seepage channel model of different pores and fissure coal samples. The characteristic parameters are determined by on-site measurement to verify the accuracy of the proposed analysis method. The results show that the characteristic parameters of each seepage flow studied differ from those measured in the field; however, the difference is small. The seepage pressure in time and space can more accurately describe the changes in the tensile parameters. The spatial dimension seepage pressures forms three-stage distribution along the radial direction. The maximum seepage velocity is about 16 m/month, and the radial seepage range is 221 ∼ 235 m. The comprehensive analysis method based on the new seepage model quantitatively reflects the changes in seepage characteristic parameters and enhances the methods of seepage research. [ABSTRACT FROM AUTHOR]

In the context of an increasingly extreme climate, Urban Heat Island (UHI) mitigation of communities through ventilation has recently attracted more attention. To explore the impact mechanisms of different morphological renovation schemes on its wind and thermal environment, this paper selected the Laozheng Community as a case study and: (1) analyzed measured data to quantitatively investigate the UHI within the community; (2) established the CIM-WTEPS system to construct community information models and to conduct wind environment parametric simulation for seven micro-renovation schemes across three levels; (3) performed correlation analyses between morphology indicators and wind environment indicators; (4) conducted the thermal environment parametric simulation of the community under different schemes. The results reveal that: (1) the Laozheng Community exhibits the Urban Heat Island Intensity (UHII) of up to 6 °C; (2) apart from the " Hollowing " scheme, which deteriorates the community wind environment, all other schemes optimize it, potentially increasing the average wind speed by up to 0.03m/s and in the renovated area by up to 0.42 m/s; (3) building density is highly correlated with the average wind speed and the proportion of calm wind area, with correlation coefficients of −0.916 (p < 0.01) and 0.894 (p < 0.01), respectively; (4) the adding of shading facilities can enhance the proportion of areas with lower Universal Thermal Climate Index (UTCI) without adversely affecting the optimization effects of the wind environment, achieving an maximum increase of 3.1%. This study provides a reference for optimizing the community's microclimate through morphological micro-renovations and detailed operations, aiding designers in better controlling community morphology for in future community renewal and design planning, thereby creating a more hospitable outdoor environment. [ABSTRACT FROM AUTHOR]

This study investigates the vibration response and dynamic characteristics of the Shigudeng Pavilion under environmental excitation, employing a comprehensive approach that includes vibration response measurements, theoretical analysis, and finite element numerical simulation. An in-depth examination of the appearance and stress status of the Shigudeng Pavilion in Yao Ancient Village in southern Hunan was conducted, and the horizontal acceleration of different floors of the pavilion under environmental excitation was ascertained through field measurements. The NExT-ERA method was utilized to identify the modal parameters (frequency, damping ratio, and vibration pattern) of the measured timber construction. Subsequently, a finite element analysis model of the ancient timber building was developed and refined using ANSYS Workbench finite element software. This study proposes a specific repair plan addressing apparent defects and structural damage in the measured ancient timber building, offering theoretical and technical references for the conservation and repair of similar structures. [ABSTRACT FROM AUTHOR]

In view of the none ground grouting reinforcement and well point dewatering conditions for shield receiving of conventional mine tunnel under building and to avoid excessive deformation of ground surface and building and ensure the shield receiving of anhydrous conditions, the shield receiving scheme of advanced large pipe shed+two end walls+backfill mortar in the tunnel+dewatering in the caisson in the tunnel is proposed. The shield receiving project of mine-method tunnel under buildings in the section of Keyuan-Jiuxing Avenue of Chengdu Metro Line 5 is taken as the background, the finite element method is used to analyze and study the settlement and deformation law of the ground surface and buildings, which is verified by field measurement. The research results show that: based on the shield receiving scheme of backfilling mortar body in the tunnel and sinking well dewatering, the extreme value of surface settlement is 3.81 mm, which is less than the control value of surface vertical deformation. In addition, the shield tunneling within the range of about 35 m from the end wall of the mine method tunnel has a significant impact on the surface settlement, and monitoring and measurement shall be strengthened during the construction. The settlement extreme value of the building directly above the shield receiving section is 8.52 mm, which is also less than the control value of the building settlement. The extreme values of ground surface and building settlement are located directly above the axis of the shield tunnel, and the field measured values are basically consistent with the calculated values. Therefore, the shield receiving technical scheme is reasonable, feasible, safe and reliable. [ABSTRACT FROM AUTHOR]

In order to analyze the variation characteristics and formation mechanism of environmental vibration caused by metro operation, field measurement of ground vibration and tunnel wall vibration are carried out along a metro line in Beijing. Vibration sample data of all trains in a whole day are analyzed statistically. And the main reasons for the discreteness of environmental vibration are summarized by comparing the vibration variety rules of different trains and different sections. The result shows as following. Firstly, the difference of vibration level at ground point can reach at most 14.6 dB, with a large degree of dispersion. Although the average value of twenty trains could meet the requirement of the standard prescribed limit, but there is still 30% ~ 50% of vibration values exceeding the standard prescribed limit. Secondly, the difference of vibration level at tunnel points reaches at most 22.1 dB, which is caused by the abnormal status of five vehicles in all trains on the day with the symptom of wheel irregularity. And the average value of maximum Z weighted vibration acceleration level (VLZmax) at tunnel wall points caused by them is 90.6 dB. Thirdly, vibration level at tunnel wall points between different sections induced by thesame vehicle is changed notably. And there is an important correlation with vehicle status. When the wheel is out of roundness visibly, the vibration level difference between different sections is changed more significantly. The maximum noise level can reach 10.7 dB, which is twice of 'normal vehicle', indicating that the deterioration of wheel state and track state will further change the wheel-rail interaction and aggravate the environmental vibration level. In addition, after wheel reprofiled of abnormal vehicles, the vibration level at ground point close to building is effectively reduced and all vibration values are reduced to less than 70 dB. [ABSTRACT FROM AUTHOR]

The electrification of the transport sector is accompanied by a massive increase of charging infrastructure which is supplied by the public distribution grid. Grid reinforcements and expansions are necessary. This publication investigates an alternative by using an existing DC-electric tram grid as the supply source. For this, long term field measurements of one year at the tram grid of Nordhausen, Germany, are presented. Furthermore, a realistic Power-Hardware-in-the-Loop (PHiL) test environment based on measurement data and a simulation model of the tram grid is realised picturing the highly fluctuating grid behaviour. The simulation model is validated based on the field measurement data and the deviation to measured data is calculated. The PHiL environment is used for tests with a 50kW charging station demonstrator that performs a complete charging cycle of an emulated electric vehicle (EV). The additional voltage drop and load on the tram grid that is caused by the charging process is shown and compared to a scenario without electric charging.

With the normalization of deep mining, the problem of mine thermal damage has been widely concerned. In this paper, 64 logging temperature data of surface boreholes of Zhujidong coalfield in Huainan City, Anhui Province, China, were summarized and sorted. The temperature data of 12 measuring points at the current main working level of −906 m and −965 m were measured. The ground temperature conditions of the vertical direction, horizontal direction, and main coal seam floor in the coalfield were analyzed. The characteristics of the present geothermal field and roadway heat damage, and its influencing factors were discussed. The results showed that the geothermal gradients of this area are between 1.7 ℃/hm and 3.6 ℃/hm, and the average geothermal gradient is 2.607 ℃/hm. It shows the transmission of warming in the vertical direction and horizontal direction shows the ground temperature lowering from south to north, east to west. The geothermal field in this area is mainly affected by the geological structure, and the thermal physical properties of rocks, magmatic rocks and groundwater activities also have a certain effect. At present, most of the main work level has reached the first heat hazard area, and some are in the second heat hazard area, according to Chinese regulations. The working face temperature is keeping above 28 7 ℃ and the relative humidity is being maintained above 70% for a long time. The problem of heat damage is extremely serious. It is suggested to construct the thermal environment control measures combining active and passive ways.

High hydrostatic pressure can cause common problems such as cracking and leakage in the lining of railway tunnels during operation. A clear understanding of the magnitude and distribution characteristics of hydrostatic pressure in tunnel lining under high-pressure conditions is crucial for optimizing the structural design of tunnel lining. In this study, professional equipment was first selected to measure the lining water pressure of two typical sections of Tunnel A on site, and the pressure distribution characteristics were analyzed; Then, a calculation model of the tunnel under high hydrostatic pressure was established using FLAC3D numerical calculation software. Select several calculation parameters and within a reasonable range of values, select multiple values for each parameter instead of just taking one value to form 60 working conditions, and calculate the corresponding tunnel lining water pressure for each working condition. Analyze the correlation between static water pressure and calculation parameters under various working conditions, propose a preliminary calculation formula for tunnel lining static water pressure, and finally use SPSS statistical calculation software to fit the final calculation formula for lining water pressure. This formula is applicable to the calculation of lining hydrostatic pressure under various parameters and is a universal calculation formula for tunnel lining hydrostatic pressure. Our proposed formula is very consistent with on-site measured data under similar geology conditions, providing a new method for calculating the hydrostatic pressure of tunnel lining.

This study analyses the performance of an integrated transcritical CO2 (R-744) refrigeration system operating in winter conditions within a supermarket in Trento, north Italy. This system fulfils multiple functions, providing the heating (for domestic hot water and space heating), cooling, and freezing capabilities for the supermarket. Energy analysis reveals that the average value of the total coefficient of performance, total COP, over the entire study period is calculated at 2.47. Notably, the medium-temperature (MT) compressor rack exhibits the highest power consumption, especially in sub −5 °C conditions. The auxiliary (AUX) compressor rack and the gas cooler (GC) fan contribute significantly to the electrical power usage. The air conditioning (AC) heating load is consistently high, averaging 41.6 kW, while the domestic hot water (DHW) heating load remains stable at approximately 5 kW. The refrigeration demands include an average MT cooling load of 25.86 kW and a low-temperature (LT) freezing load of 10–15 kW, with an average of 13.76 kW. The current study also delves into exergy analysis, disclosing an overall system exergy efficiency of 22.4%. The AUX compressor rack is identified as the primary exergy destructor, followed by the GC, AC coils, MT compressor rack, and the ejector. The LT compressor rack has the highest exergy efficiency, followed by the MT and LT expansion valves. [ABSTRACT FROM AUTHOR]

Hydrodynamic as well as balance analysis of flow or discharge conditions in surface streams cannot be done without knowledge of the basic hydraulic parameters of the flow. These are, for example, the bathymetry of the water body, the distribution of velocities in the transverse and longitudinal directions, roughness, etc. To determine the value of discharge in a given cross section profile, it is necessary to know the discharge area and the velocity profile. There are several devices and methods for measuring these quantities. Recently, devices based on the application of the Doppler principle are increasingly being used to determine velocity profiles and discharges in field conditions. In ideal conditions, the use of such devices is very effective, but in the case of the presence of aquatic vegetation below the water surface, a problem may arise. The paper analyses the accuracy of determining the discharge area in a lowland stream with a small longitudinal slope with the presence of aquatic vegetation using the Acoustic Doppler Current Profiler (ADCP) device (River Surveyor, SonTek/a Xylem brand). The results of the analysis show that for such cases, this method shows limitations, the extent of which depends on the used sub-method (Bottom Track or Vertical Beam), as well as on the amount of aquatic vegetation below the water surface. [ABSTRACT FROM AUTHOR]

This study examined the influence of nonuniform wind fields in valleys on the dynamic responses of high-speed trains and long-span bridges. The wind field in a valley is considerably different from a theoretical uniform wind field in terms of mean and fluctuating wind characteristics because of the influence of the speed-up effect of crosswinds. The spatial nonuniformity of a valley wind field along a bridge span is equivalent to a "sudden change" load effect for running trains, which increases the complexity of the wind fields in the train–bridge system and may diminish the running performance of trains. To better understand the nonuniform characteristics of wind fields in valleys, a multipoint synchronous field measurement along the main girder of a long-span suspension bridge was conducted. Based on the measured wind field characteristics, a refined numerical wind field was established for conducting the coupling vibration analysis between train and bridge. It is shown that the valley induces an obvious nonuniformity in the mean wind speed, turbulence intensity, and turbulence integral along the bridge span. A higher mean wind speed and lower turbulence intensity occurs at the midspan of the main girder than at the two side spans. A refined numerical wind field can be established to identify the most unfavorable time for a train to cross the bridge from the perspective of the wind speed field experienced by the train. Compared with a uniform wind field, the nonuniform wind field has a more obvious effect on the lateral deformation of a bridge than on the vertical deformation. When a train crosses a bridge at an unfavorable time, the running safety of the train decreases, but the running comfort coefficient of the train is less affected. The limited influence of nonuniform crosswind on train-running comfort is caused by the difference of lateral bridge deformation between two wind fields. [ABSTRACT FROM AUTHOR]

The appropriate temperature and humidity environment in the underground utility tunnel is the guarantee for the safe operation of various professional pipelines and ancillary facilities. An underground integrated pipe gallery unit module under natural ventilation conditions was taken as the research object. From May 2021 to November and from October 2022 to March 2023, the temperature and humidity inside and outside the pipe gallery and the inlet and outlet wind speed were measured on site, and the ventilation rate was further measured. The Pearson correlation coefficient method was used to determine the significant relationship between the measured parameters. The results show that the temperature in the pipe gallery is less affected by the daily change temperature and more affected by the annual average temperature. The temperature in the corridor varies from 11. 7 ℃ to 23. 5 ℃ throughout the year. For every 5 ℃ decrease in the temperature outside the corridor, the maximum temperature in the annual corridor decreases by 1. 3 ℃, and the maximum temperature in the single-day corridor decreases by 0. 3 ℃. From 2022 to 2023, the proportion of humidity between 60% and 70% is 7. 4%, and the proportion of humidity > 70% is 3. 2%. During the study period, the proportion of ventilation times reaching 2 times/ h was 8. 3%. The correlation coefficients between the temperature outside the corridor and the temperature and humidity inside the corridor were 0. 811 and 0. 801, respectively. The results show that the temperature in the pipe gallery is less affected by the daily variation temperature and more affected by the annual average temperature. The environment in the corridor is greatly affected by the external environment, and natural ventilation is not effective in improving the temperature and humidity environment in the corridor. The research results provide basic data support for ventilation design and intelligent control technology of underground utility tunnel. [ABSTRACT FROM AUTHOR]

High hydrostatic pressure can cause common problems such as cracking and leakage in the lining of railway tunnels during operation. A clear understanding of the magnitude and distribution characteristics of hydrostatic pressure in tunnel lining under high-pressure conditions is crucial for optimizing the structural design of tunnel lining. In this study, professional equipment was first selected to measure the lining water pressure of two typical sections of Tunnel A on site, and the pressure distribution characteristics were analyzed; Then, a calculation model of the tunnel under high hydrostatic pressure was established using FLAC3D numerical calculation software. Select several calculation parameters and within a reasonable range of values, select multiple values for each parameter instead of just taking one value to form 60 working conditions, and calculate the corresponding tunnel lining water pressure for each working condition. Analyze the correlation between static water pressure and calculation parameters under various working conditions, propose a preliminary calculation formula for tunnel lining static water pressure, and finally use SPSS statistical calculation software to fit the final calculation formula for lining water pressure. This formula is applicable to the calculation of lining hydrostatic pressure under various parameters and is a universal calculation formula for tunnel lining hydrostatic pressure. Our proposed formula is very consistent with on-site measured data under similar geology conditions, providing a new method for calculating the hydrostatic pressure of tunnel lining. [ABSTRACT FROM AUTHOR]

In order to find out whether the existing tunnel lining design theory can better fit the actual stress characteristics of the strongly weathered soft rock shield tunnel and lining segment, a case study is conducted on the shield tunnel project in the northern extension section of Nanchang Metro Line 1, and the field test is carried out to monitor the external load and structural internal force of the segment for a long time. Meanwhile, a refined numerical model of the shield is established, and the mechanical characteristics of the segment are further explored and compared with the measured data. The results show that: (1) The most significant influence of the earth pressure and water pressure outside the ring of the pipe sheet is within five rings off the segment. The earth pressure at the bottom of the tunnel is less than that at the top of the tunnel, and the water pressure accounts for the majority of the total earth pressure. (2) The distribution mode of the vertical earth pressure on the segment is "large in the middle and small at both ends". The measured value near the vault is the largest, which has a difference of nearly 20%, 30 % and 42% respectively compared with the calculated values of Terzaghi theory, Platts theory and tunnel specification method. It is more appropriate to calculate the vertical earth pressure of tunnel in strongly weathered soft rock stratum according to Terzaghi theory. (3) The internal force of the segment obtained by numerical simulation is in good agreement with the measured value. The overall bending moment of the segment exhibits a butterfly shape. The bending moment of the vault is slightly larger than that of the arch bottom. [ABSTRACT FROM AUTHOR]

To predict the vibration transmission of over-track buildings and investigate the effectiveness of countermeasures, a fully coupled three-dimensional vibration prediction model for over-track buildings with consideration of the pile–soil interaction (PSI) was proposed. The accuracy of this prediction model was validated with field data from in-situ vibration monitoring in a metro depot. The consideration of PSI improved prediction accuracy about the vibration of over-track buildings. Then the effectiveness of different mitigation measures (rail damper and ballast mat) was investigated by this prediction model. It was found that the vibration of over-track buildings was dominated by vertical vibration components. Rail dampers significantly reduced the vibration in the high-frequency range above 80 Hz, while the vibration in the low-frequency range below 10 Hz was amplificated. The insertion loss of ballast mats reached 10 dB in the frequency range above 40 Hz except at the resonance frequency of the track, and mitigation effectiveness gradually decreased with increasing story height. This proposed method can predict the vibration level within over-track buildings and is an effective tool to guide the vibration mitigation design of over-track buildings. [ABSTRACT FROM AUTHOR]

The stability of inclined shaft lining structure (ISLS) in complex water-rich strata is affected by many factors, such as water pressure, joint, soft rock, lining corrosion and so on. The instability of the ISLS will affect the safe and efficient coal mine production. Bathe sed on the geological conditions of the Xiaobaodang coal mine, this paper tested the evolution characteristics of concrete composition in long-term water seepage areas and revealed the influence mechanism of corrosion weakening of shaft lining (SL) in water-rich strata. Meanwhile, transient electromagnetic, ground penetrating radar, and infrared monitoring are used to detect the water-rich zones, and damage zones of surrounding rock and lining water seepage zones, and a three-level safety evaluation model for the instability risk of ISLS is constructed. Water abundance of the surrounding rock, surrounding rock deterioration, and shaft lining seepage were the specific indicators in the model. The main inclined shaft (MIS) in the studied coal mine is divided into three levels: non instability risk zone, potential instability risk zone, and high instability risk zone. According to the evaluation results, comprehensive prevention and control measures of “hydrophobic hole drainage” and “back-lining grouting” are adopted for the water inrush source and the surrounding rock micro-crack water channel. The precise prevention and control of ISLS is realized. The research results also provide a reference for the stability evaluation of ISLS and the accurate prevention and control under similar conditions. [ABSTRACT FROM AUTHOR]

An innovative approach for measuring wind fields in urban building clusters using Unmanned Aerial Vehicles (UAVs) is presented. This method captures the distribution of wind fields within clusters. The results indicate that building architecture has a significant influence on wind flow characteristics at 15 m and 25 m height levels. Particularly, areas adjacent to the buildings and the wake section exhibit notable variations in wind speed and turbulence intensity compared to the incoming flow. The regions most affected include the areas flanking the buildings on either side and the intermediate section of the wake. The flow separation and convergence of incoming wind from the windward sides of the buildings notably amplify the wind load, resulting in a significant shift in wind speed and turbulence intensity within pedestrian pathways. The use of UAVs for wind measurements enables a flexible and efficient assessment of urban wind fields. These findings pave the way for further research into wind field measurements in urban architecture and a better understanding of the interference effects of buildings. [ABSTRACT FROM AUTHOR]

Daylight can contribute to substantial reductions in the energy consumed by artificial lighting applications. However, issues such as visual comfort, illumination intensity, and availability represent major issues when daylight is relied upon to illuminate buildings. There are many technologies that are used to control received sunlight and minimize its side effects. The placement of solar film sheets on window glass is a common and popular method utilized in many buildings to minimize electric lighting energy consumption without causing undue visual discomfort to occupants. To examine the practicality of this application and its effect on room lighting, a modern office was selected in which to conduct this field study. Two measures were used to evaluate this technique: firstly, field measurements and their comparison to the specified standard illumination levels; and secondly, a short-form questionnaire survey conducted to obtain occupants' opinions of the office lighting. Actual measurements were conducted in the selected office spaces, with and without applying solar control film coating on the window glass. Indoor luminance levels and lighting comfort were systematically recorded and analyzed. The findings of this study show that using a solar film with a visible light transmittance of 50% can achieve savings in energy consumption of up to 33% if utilized as part of an integrated lighting system. [ABSTRACT FROM AUTHOR]

The natural frequency of the long-span steel structure corridor is close to the pedestrian step frequency, which makes it very easy to cause resonance. This paper aims to study crowd-induced vibration control of long-span steel pedestrian corridors with different dynamic characteristics by combining methods of site measurement and numerical simulation. First, based on the steel structure corridor project of a multi-tower structure, the field modal test and the acceleration response under pedestrian load excitation are measured, and the dynamic characteristics and acceleration response under different frequency pedestrian loads are studied. Then, the finite element model of the large-span corridor is established, and the results of the measured and numerical simulation are compared and analyzed. Finally, with the relevant norms, a reasonable evaluation of pedestrian comfort is carried out. The results show that this paper's measured and finite element results have a certain accuracy. The damping characteristics of humans can absorb the vibration energy of the structure to reduce the vibration acceleration of the structure, and the results are conservative when human action is not considered. After installing the TMD system, the acceleration response of the corridor is significantly reduced, and the vibration reduction effect reaches 54%, which meets the comfort control requirements of the large-span corridor under pedestrian load excitation. The research results and methods in this paper can have particular engineering practical values for carrying out field measurements and comfort control in similar projects and provide a reference for engineering designers. [ABSTRACT FROM AUTHOR]

In order to ensure the safety of temporary piers during bridge construction, it is necessary to analyze the water flow effects on temporary piers during flood periods. Based on the practical engineering of a new bridge in Jiangxi province, a three-dimensional numerical model was established using the Reynolds Time Average Navier–Stokes equation (RANS) and SST k- ω turbulence model to simulate the flow force on three-column temporary piers in series. The stress state of the temporary pier was obtained under different flow velocities and submergence depths. The distribution characteristics of the flow field around the temporary pier and the flow force characteristics acting on the temporary pier were analyzed and compared with the monitoring measurement data and the Morison equation calculation data. The results indicate that the local flow was accelerated on both sides of the temporary pier, but the local acceleration effect along the river flow direction was weakened. The flow velocity of the water around the temporary pier decreases with the increasing of river depth. The pressure on the outer surface of the temporary pier is basically negative pressure, except for the positive pressure on the upstream side. The absolute value of the negative pressure on both sides is much greater than the positive pressure on the upstream side. As the submergence depth and flow velocity increase, the pressure in each area gradually increases. The pressure distribution of the upstream pier is basically symmetrical, while the pressure distribution of the middle and downstream piers is asymmetric due to the influence of the vortex shedding from the front pier, resulting in a change in the water flow incidence point. The turbulence intensity in each region of the flow field shows a trend of first increasing and then decreasing with the depth of the water flow. The drag coefficient and lateral force coefficient of the temporary pier are basically not affected by the inflow velocity, but the resistance and lateral force increase with the increase in submergence depth and inflow velocity. [ABSTRACT FROM AUTHOR]

In this work a mathematical approach to calculate solar panel temperature based on measured irradiance, temperature and wind speed is applied. With the calculated module temperature, the electrical solar module characteristics is determined. A program developed in MatLab App Designer allows to import measurement data from a weather station and calculates the module temperature based on the mathematical NOCT and stationary approach with a time step between the measurements of 5 minutes. Three commercially available solar panels with different cell and interconnection technologies are used for the verification of the established models. The results show a strong correlation between the measured and by the stationary model predicted module temperature with a coefficient of determination R2 close to 1 and a root mean square deviation (RMSE) of ≤ 2.5 K for a time period of three months. Based on the predicted temperature, measured irradiance in module plane and specific module information the program models the electrical data as time series in 5-minute steps. Predicted to measured power for a time period of three months shows a linear correlation with an R2 of 0.99 and a mean absolute error (MAE) of 3.5, 2.7 and 4.8 for module ID 1, 2 and 3. The calculated energy (exemplarily for module ID 2) based on the measured, calculated by the NOCT and stationary model for this time period is 118.4 kWh, resp. 116.7 kWh and 117.8 kWh. This is equivalent to an uncertainty of 1.4% for the NOCT and 0.5% for the stationary model.

In this work data from outdoor measurements, acquired over the course of up to three years on commercially available solar panels, is used to determine the temperature coefficients and compare these to the information as stated by the producer in the data sheets. A program developed in MatLab App Designer allows to import the electrical and ambient measurement data. Filter algorithms for solar irradiance narrow the irradiance level down to ~1000 W/m2 before linear regression methods are applied to obtain the temperature coefficients. A repeatability investigation proves the accuracy of the determined temperature coefficients which are in good agreement to the supplier specification if the specified values for power are not larger than -0.3%/K. Further optimization is achieved by applying wind filter techniques and days with clear sky condition. With the big (measurement) data on hand it was possible to determine the change of the temperature coefficients for varying irradiance. As stated in literature we see an increase of the temperature coefficient of voltage and a decline for the temperature coefficient of power with increasing irradiance.