The observed deflections and internal forces of pile-anchor retaining excavation were studied in spring area in Jinan city of China. Based on field measured data, the ground surface settlement, deflection of retaining...The observed deflections and internal forces of pile-anchor retaining excavation were studied in spring area in Jinan city of China. Based on field measured data, the ground surface settlement, deflection of retaining piles and wall, internal force analysis of concrete piles, axial anchoring forces, groundwater table, and the deformation of surround building and pipelines were investigated. The results indicates that the combining application of concrete piles, jet grouting columns and anchors support system can effectively control excavation-induced surface ground settlements. The field maximum lateral wall deflections are between 0.o2% and o.19% of the excavation depth due to the competitive site conditions. The bending moment-depth relationship curve is S-type. Groundwater leakage results in the sharp drop in groundwater level, which is part of the reasons for the adjacent building settlement. The axial anchoring forces of the upper layer of anchors increase gradually during the excavation, but those of the lower layer of anchors slightly reduced firstly and then tend to be stable during the excavation procedure. In comparison with the histories of excavation cases, the small lateral wall deflection in this study results from the favorable site condition and the relative rigidity of the retaining structure system.展开更多
This paper deals with fuzzy intelligent position control of electro-hydraulic activated robotic excavator for the control of boom, arm and bucket axes. Intelligent control systems are required to overcome unde- sirabl...This paper deals with fuzzy intelligent position control of electro-hydraulic activated robotic excavator for the control of boom, arm and bucket axes. Intelligent control systems are required to overcome unde- sirable stick-slip motion, limit cycles and oscillations. Models of electro-hydraulic servo controlled front end loader excavators are highly nonlinear. The nonlinear model accounts for fluid flow rate of valve, pump hydraulics, and friction forces. The friction forces are modelled by Coulomb, viscous and Stribeck function. Interval Type-2 Fuzzy Logic Controller （IT2FLC） is used to study the time-domain position responses of axes in the presence of external applied load. It has the ability to control the position of each of the three axes with minimum actuator position errors. Models presented are accurate and study the dynamics of the actuator and load. To improve the transient behaviour of the robotic excavator, we elim- inated iitter of the bucket movement in the presence of nonlinearities.展开更多
基金supported by the Chinese Fundamental Research Funds for the Central Universities(Grant No.2242014R30020)the Personnel Training Fund for Outstanding Young Teacher of Qinglan Project of Higher Education in Jiangsu Province,China
文摘The observed deflections and internal forces of pile-anchor retaining excavation were studied in spring area in Jinan city of China. Based on field measured data, the ground surface settlement, deflection of retaining piles and wall, internal force analysis of concrete piles, axial anchoring forces, groundwater table, and the deformation of surround building and pipelines were investigated. The results indicates that the combining application of concrete piles, jet grouting columns and anchors support system can effectively control excavation-induced surface ground settlements. The field maximum lateral wall deflections are between 0.o2% and o.19% of the excavation depth due to the competitive site conditions. The bending moment-depth relationship curve is S-type. Groundwater leakage results in the sharp drop in groundwater level, which is part of the reasons for the adjacent building settlement. The axial anchoring forces of the upper layer of anchors increase gradually during the excavation, but those of the lower layer of anchors slightly reduced firstly and then tend to be stable during the excavation procedure. In comparison with the histories of excavation cases, the small lateral wall deflection in this study results from the favorable site condition and the relative rigidity of the retaining structure system.
文摘This paper deals with fuzzy intelligent position control of electro-hydraulic activated robotic excavator for the control of boom, arm and bucket axes. Intelligent control systems are required to overcome unde- sirable stick-slip motion, limit cycles and oscillations. Models of electro-hydraulic servo controlled front end loader excavators are highly nonlinear. The nonlinear model accounts for fluid flow rate of valve, pump hydraulics, and friction forces. The friction forces are modelled by Coulomb, viscous and Stribeck function. Interval Type-2 Fuzzy Logic Controller （IT2FLC） is used to study the time-domain position responses of axes in the presence of external applied load. It has the ability to control the position of each of the three axes with minimum actuator position errors. Models presented are accurate and study the dynamics of the actuator and load. To improve the transient behaviour of the robotic excavator, we elim- inated iitter of the bucket movement in the presence of nonlinearities.
