Adjacent high-rise building with CFG pile composite foundation was studied using model test method to investigate stress and displacement of the foundation pile retaining structure, the subsidence and transmogrificati...Adjacent high-rise building with CFG pile composite foundation was studied using model test method to investigate stress and displacement of the foundation pile retaining structure, the subsidence and transmogrification law of the composite foundation. Two different project cases with and without high-rise building adjacent to pile foundation were compared. The relationships of slope pile bending moment, earth pressure, pile top displacement and complex settlement with respect to time were obtained. 1) When there is no adjacent building, the displacement of supporting system caused by excavation is mainly in the horizontal direction; while when the adjacent building exists, the displacement of supporting system will be vertical. 2) When the excavation depth is less than or equal to the adjacent building's composite foundation depth, the force of supporting structure is uniform and has small value, at the same time, the pile strength is in fully use and the foundation is stable; while when the excavation depth is greater than the depth of adjacent building's composite foundation, the results will be opposite. 3) During the excavation process, the adjustment of the composite ground loads on the supporting structure is carried out downward and the force of the supporting structure is reduced through the deformation of the bearing layer.展开更多
Reducing the blasting vibration is important for blasting excavation in subway tunnel construction.Taking the 3rd bid section of Line 3 of Qingdao subway project as an example,the distance between tunnel vault and gro...Reducing the blasting vibration is important for blasting excavation in subway tunnel construction.Taking the 3rd bid section of Line 3 of Qingdao subway project as an example,the distance between tunnel vault and ground is 5 ~ 8 m.In order to insure the safety of the upper buildings,technologies of parallel cut with large diameter empty hole,one-time initiation and delay by parts,and multiple shallow holes were adopted in the project.The results showed that the maximum value of vertical vibration was limited in the criterion allowance,and the upper buildings were not damaged.Besides,problems were solved that the number of nonel detonator was difficult to meet the requirements of excavating a large cross-section tunnel by blasting,multiple cross-section could’t be initiated simultaneously,and construction efficiency was low,which ensure the construction safety and schedule.展开更多
Hydropower development in China is concentrated in the country's western regions.Among all the rivers in China,the lower course of the Jinsha River contains the richest hydro-energy resource,and therefore,4 mammot...Hydropower development in China is concentrated in the country's western regions.Among all the rivers in China,the lower course of the Jinsha River contains the richest hydro-energy resource,and therefore,4 mammoth hydropower plants are under construction on this particular section of the river at Wudongde,Baihetan,Xiluodu,and Xiangjiaba.The water-blocking structures of the hydropower facilities at Wudongde,Baihetan and Xiluodu are all arch dams of around 300 m high.In view of changes in the geological conditions at the foundation of the Xiluodu dam on the riverbed after excavation started,the designs of expanding foundation surface excavation and dovetailing the dam body and foundation rock on both upstream and downstream sides were introduced,allowing the arch dam and foundation to fit each other and improving the stress conditions of the dam body and foundation.By dividing the dam body into various concrete sections,the dynamic properties of concrete were adequately adjusted to the distribution of stress in the dam body.In addition,the use of the most optimal concrete material and mixture ratio allowed thermodynamics of concrete to satisfy the requirements of the strength,durability,temperature control and crack prevention of the concrete.Moreover,rigorous temperature control measures were introduced to prevent harmful cracking,thus enhancing the integrity of the arch dam.Furthermore,sophisticated construction machinery,scientific testing methods,and sound construction techniques were employed to ensure the uniformity and reliability of concrete placement.The "Digital Dam" for the Xiluodu project,which is based on the theory of total life cycle,has supplied strong support for construction process control and decision-making.展开更多
基金Project(41202220) supported by the National Natural Science Foundation of ChinaProject(20120022120003) supported by the Research Fund for the Doctoral Program of Higher Education,ChinaProject(2-9-2012-65) supported by the Fundamental Research Funds for the Central Universities,China
文摘Adjacent high-rise building with CFG pile composite foundation was studied using model test method to investigate stress and displacement of the foundation pile retaining structure, the subsidence and transmogrification law of the composite foundation. Two different project cases with and without high-rise building adjacent to pile foundation were compared. The relationships of slope pile bending moment, earth pressure, pile top displacement and complex settlement with respect to time were obtained. 1) When there is no adjacent building, the displacement of supporting system caused by excavation is mainly in the horizontal direction; while when the adjacent building exists, the displacement of supporting system will be vertical. 2) When the excavation depth is less than or equal to the adjacent building's composite foundation depth, the force of supporting structure is uniform and has small value, at the same time, the pile strength is in fully use and the foundation is stable; while when the excavation depth is greater than the depth of adjacent building's composite foundation, the results will be opposite. 3) During the excavation process, the adjustment of the composite ground loads on the supporting structure is carried out downward and the force of the supporting structure is reduced through the deformation of the bearing layer.
文摘Reducing the blasting vibration is important for blasting excavation in subway tunnel construction.Taking the 3rd bid section of Line 3 of Qingdao subway project as an example,the distance between tunnel vault and ground is 5 ~ 8 m.In order to insure the safety of the upper buildings,technologies of parallel cut with large diameter empty hole,one-time initiation and delay by parts,and multiple shallow holes were adopted in the project.The results showed that the maximum value of vertical vibration was limited in the criterion allowance,and the upper buildings were not damaged.Besides,problems were solved that the number of nonel detonator was difficult to meet the requirements of excavating a large cross-section tunnel by blasting,multiple cross-section could’t be initiated simultaneously,and construction efficiency was low,which ensure the construction safety and schedule.
文摘Hydropower development in China is concentrated in the country's western regions.Among all the rivers in China,the lower course of the Jinsha River contains the richest hydro-energy resource,and therefore,4 mammoth hydropower plants are under construction on this particular section of the river at Wudongde,Baihetan,Xiluodu,and Xiangjiaba.The water-blocking structures of the hydropower facilities at Wudongde,Baihetan and Xiluodu are all arch dams of around 300 m high.In view of changes in the geological conditions at the foundation of the Xiluodu dam on the riverbed after excavation started,the designs of expanding foundation surface excavation and dovetailing the dam body and foundation rock on both upstream and downstream sides were introduced,allowing the arch dam and foundation to fit each other and improving the stress conditions of the dam body and foundation.By dividing the dam body into various concrete sections,the dynamic properties of concrete were adequately adjusted to the distribution of stress in the dam body.In addition,the use of the most optimal concrete material and mixture ratio allowed thermodynamics of concrete to satisfy the requirements of the strength,durability,temperature control and crack prevention of the concrete.Moreover,rigorous temperature control measures were introduced to prevent harmful cracking,thus enhancing the integrity of the arch dam.Furthermore,sophisticated construction machinery,scientific testing methods,and sound construction techniques were employed to ensure the uniformity and reliability of concrete placement.The "Digital Dam" for the Xiluodu project,which is based on the theory of total life cycle,has supplied strong support for construction process control and decision-making.
