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1.
光伏发电功率存在波动性,且光伏出力易受各种气象特征影响,传统TCN网络容易过度强化空间特性而弱化个体特性。针对上述问题,文中提出一种基于VMD和改进TCN的短期光伏发电功率预测模型。通过VMD将原始光伏发电功率时间序列分解为若干不同频率的模态分量,将各个模态分量以及相对应的气象数据输入至改进TCN网络进行建模学习。利用中心频率法确定VMD的最优分解模态分解个数。在传统TCN预测模型的基础上,使用DropBlock正则化取代Dropout正则化以达到抑制卷积层中信息协同的效果,并引入注意力机制自主挖掘并突出关键气象输入特征的影响,量化各气象因素对光伏发电的影响,从而提高预测精度。以江苏省某光伏电站真实数据为例进行仿真实验,结果表明所提预测方法的RMSE为0.62 MW,MAPE为2.03%。 相似文献
2.
《Soils and Foundations》2022,62(3):101159
Suffusion erosion, characterized as the selective detachment and transportation of finer particles by seepage flow, is hazardous to the stability and serviceability of geotechnical structures. The removal of finer particles deteriorates the structure and fabric of the soil, leading to the degradation of its mechanical properties. Studies into the effects of suffusion on mechanical behavior have so far produced disparate results depending on the pre-erosion relative density of the specimens tested. To investigate this issue, small cyclic and monotonic loading tests were performed on intact and eroded gap-graded silty sand specimens in three dispersed density states, using a triaxial cell modified for the purpose of erosion. The variation of Young's modulus showed an inverse relationship with the pre-erosion density of the specimen, as the small strain stiffness decreased in the dense cases and increased in the loose cases. Conversely, Poisson's ratio increased in value as suffusion progressed regardless of the initial density of the specimens. In the contractive phase of monotonic loading, the densification of the coarse soil skeleton by the downward seepage flow resulted in a decrease in contractiveness and an increase in secant stiffness. In the dilative phase, the increase in porosity by the erosion of finer particles reduced the dilatancy and peak strength of the specimens. The results suggest that the pre-suffusion density determines the primary locus of affected mechanical behavior in triaxial compression, which shifts from the contractive phase to the dilative phase with the increase in pre-suffusion density. The critical state strength, inferred using stress–dilatancy theory, was largely unaffected by the erosion of finer particles. As the results indicate, pre-erosion density may be of practical significance in assessing the vulnerability to deterioration and collapse of geotechnical formations and structures subjected to suffusion erosion. 相似文献
3.
《Soils and Foundations》2022,62(5):101205
Global sustainable development faces challenges in greenhouse gas emission, consumption of non-renewable resource and energy, waste landfilling, and environmental pollution. Geotechnical engineering also faces similar challenges; for example, the use of cement and lime for stabilisation/solidification (S/S) of contaminated soil is associated with carbon dioxide (CO2) emission and consumption of limestone and energy. In this context, this study introduces a sustainable S/S method by using an industrial waste, ladle furnace slag (LFS), and a greenhouse gas, CO2, to replace common additives for S/S of lead (Pb)-contaminated soil. LFS was first mixed with Pb-contaminated soils and then CO2 was introduced into the soil for carbonation. The results showed that LFS-stabilised Pb-contaminated soils could achieve CO2 uptake up to 18% of LFS mass. After carbonation, the concentration of leached Pb from contaminated soils was reduced by three orders of magnitude than that without carbonation, demonstrating higher S/S efficacy than cement, lime, and magnesia. Additionally, this method can improve soil strength, as well as reduce non-renewable resource consumption, energy use, LFS landfilling, and additive cost. 相似文献
4.
《Soils and Foundations》2022,62(5):101215
This technical report on the compression behavior of soft soils in the Colombian capital, Bogotá, was conducted because the city’s recent construction history has led to excessive settlement of soils in the city over the last forty years. Several studies have shown the city’s soil to contain unusually high concentrations of diatoms. The stationary piston method was used to obtain samples from depths of between five and 100 m. Samples were subsequently examined in the laboratory, being subjected to triaxial and oedometer compression tests, and tested also for Atterberg limits and grain size distributions. Test results for undisturbed soil returned very high liquid limit values, compressibility indices CC, secondary compression coefficients Cα, and soil structure effects. Some samples showed particle mixtures of different sizes, mineralogy, and diatom concentrations. Although high CC and Cα indices explain the excessive settling of the city’s buildings, most construction projects do not currently take settlement caused by secondary compression into account. This report shows that secondary compression is an important parameter in the total settlement of buildings in Bogotá and that, furthermore, settlement is also affected by geological history. Finally, useful correlations such as the relationship between the liquid limit, Cα and geological history are presented. 相似文献
5.
6.
《Soils and Foundations》2022,62(5):101220
In numerous real-life civil engineering practices, including multi-stage embankment construction and foundation pit excavation, the direction of the major principal stress σ1 becomes rotated. In these cases, the granite residual soil may be subjected to inclined consolidation (IC) with σ1 being inclined, because of the relatively high permeability as a result of the fissures formed during weathering. While the effect of the σ1 direction during the shear on the strength of granite residual soil (inherent strength anisotropy) has been primarily established, little is known about how the soil strength is affected by the direction of σ1 during consolidation. This paper presents the effects of IC on the shear strength properties of natural granite residual soil through undrained hollow cylinder torsional shear tests. The effect of the soil structure is also considered by testing remolded soil specimens. The results reveal that while IC changes neither the shape of stress–strain curve nor the specimen features at failure, it leads to an increased ultimate shear strength in terms of both the undrained strength and stress ratio, with the remolded soil being more affected. The presented data provide new insights into the understanding of residual soil strength behaviors. 相似文献
7.
《Soils and Foundations》2022,62(6):101224
Internal erosion is a major threat to hydraulic earth structures, such as river levees and dams. This paper focuses on suffusion and suffosion phenomena which are caused by the movement of fine particles in the granular skeleton due to seepage flow. The present study investigates the impact of internal erosion on the dynamic response under cyclic torsional shear and monotonic responses under triaxial compression and torsional simple shear. A series of experiments, using a gap-graded silica mixture with a fines content of 20%, is performed under loose, medium, and dense conditions using a novel erosion hollow cylindrical torsional shear apparatus. The erosion test results indicate that the critical hydraulic gradient and the rate of erosion are density-dependent, where a transition from suffosion to suffusion is observed as the seepage continues. Regardless of the sample density, variations in the radial strain and particle size distribution, along the specimen height after erosion, are no longer uniform. Furthermore, the dynamic shearing results show that the small-strain shear modulus increases, but the initial damping ratio decreases after internal erosion, probably due to the removal of free fines. In addition, the elastic threshold strain and reference shear strain values are found to be higher for the eroded and non-eroded specimens, respectively. Finally, based on drained monotonic loading, the post-erosion peak stress ratio increases remarkably under triaxial compression, while that under torsional simple shear depends on the relative density where the direction of loading is normal to the direction of seepage. These observations indicate that the horizontal bedding plane becomes weaker, while the vertical one becomes stronger after downward erosion. 相似文献
8.
《Geotextiles and Geomembranes》2022,50(3):371-382
Internal stability assessment of geosynthetic-reinforced soil structures (GRSSs) has been commonly carried out assuming plane-strain conditions and dry backfills. However, failures of GRSSs usually show three-dimensional (3D) features and occur under unsaturated conditions. A procedure based on the kinematic limit-analysis method is proposed herein to assess 3D effects and the role of steady unsaturated infiltration on the required geosynthetic strength for GRSSs. A suction stress-based framework is used to describe the soil stress behavior under steady unsaturated infiltration. Based on the principle of energy-work balance, the required geosynthetic strength is determined. A comparison analysis with the prior research is conducted to verify the developed method. Two kinds of backfills, i.e., high-quality backfill and marginal backfill, are considered for comparison in this work. It is shown that accounting for 3D effects and the role of unsaturated infiltration considerably reduces the required geosynthetic strength. The 3D effects are primarily affected by the width-to-height ratio of GRSSs, and the contribution of unsaturated infiltration is mainly influenced by the soil type, flow rate, GRSS's height, and location of the water table. 相似文献
9.
《Geotextiles and Geomembranes》2022,50(3):535-544
Soil column is often investigated in the improvement of dredged slurries. Different from the smear zone, the soil column forms gradually and has extremely low permeability. This study presents an analytical solution for soil consolidation considering the increasing radius of the soil column and time-dependent discharge capacity. Based on the solution, the influence of the radius' increase on the consolidation behavior is found significant when the soil column has low permeability and large final radius, and the increase of formation time can lead to the increase of consolidation speed and final consolidation degree. 相似文献
10.
《Geotextiles and Geomembranes》2022,50(4):632-643
This paper presents an experimental study on reduced-scale model tests of geosynthetic reinforced soil (GRS) bridge abutments with modular block facing, full-height panel facing, and geosynthetic wrapped facing to investigate the influence of facing conditions on the load bearing behavior. The GRS abutment models were constructed using sand backfill and geogrid reinforcement. Test results indicate that footing settlements and facing displacements under the same applied vertical stress generally increase from full-height panel facing abutment, to modular block facing abutment, to geosynthetic wrapped facing abutment. Measured incremental vertical and lateral soil stresses for the two GRS abutments with flexible facing are generally similar, while the GRS abutment with rigid facing has larger stresses. For the GRS abutments with flexible facing, maximum reinforcement tensile strain in each layer typically occurs under the footing for the upper reinforcement layers and near the facing connections for the lower layers. For the full-height panel facing abutment, maximum reinforcement tensile strains generally occur near the facing connections. 相似文献