Studies On Design Format And Partial Factors Of Bearing Capacity Of Shiplock And Dock Pile Foundation

Ship lock is an important basic traffic structure in water transportation engineering,which can not only be used for navigation,but also improve water flow condition and communicate water.Generally,the ship lock is used to seat on the natural foundation,but for some sit with soft soil,pile foundation is often used to improve the bearing capacity,especially for the lock head.Dock is a dock building for ship repair and construction,and pile foundation is often used when the bearing capacity of foundation is insufficient.The current Code for Design of Shiplock Hydraulic Structures provides the design methods for the Shiplock Hydraulic structures,including foundation bearing capacity check,soil slope and foundation stability check and foundation settlement calculation.However,no design method of the bearing capacity of the pile foundation recommended in this code.The same is for the Design Code for Dry Dock.Fufilling the requirement of compiling Code for Pile Foundation of Waterway Engineering,reliability of vertical bearing capacity of pile foundation of ship lock and dock and the design method of partial factors are stuided in this dissertation.The research contents and main conclusions are as follows.(1)The calculation methods of the ultimate bearing capacity of single pile in pile foundation codes of ports,buildings and bridges are compared,and quantitive study is made y an example of pile foundation.It shows that the charicteristic value of ultimate bearing capacity of pile foundation calculated according to the method in Technical Code for Building Pile Foundations is the largest,followed by that in the Code for Pile Foundations of Port Engineering and the Code for Design of Foundations and Foundations of Highway Bridges and Culverts is the lowest.(2)Based on the measured vertical bearing capacity of 49 piles,the uncertainty factors,definded as ratio of measured and calculated ultimate bearing capacity of single pile,of the model of the vertical bearing capacity of single pile in the code of pile foundation of port engineering,building engineering and bridge engineering are quantified.On this basis,the reliability of bearing capacity of single pile design according to the three codes are analyzed.It shows that the reliability indexes of vertical bearing capacity of single pile desgined accprding to the Code for Design of Wharf Structure and Code for Building Pile Foundation are close to each other.Both of them are lower than the reliability index of vertical bearing capacity of single pile desgined accprding to the Code for Design of Foundations and Foundations of Highway Bridges and Culverts.Although the reliability indexes of the vertical bearing capacity of single pile in the three pile foundation codes are different,they all meet the requirements of the Unified Standard for Reliability Design of Port Engineering Structures(GB 50158-2010),Technical Specification for Building Pile Foundation(JGJ 94-2008)and Unified Standard for Reliability Design of Highway Engineering Structures(GB/T 50283-1999).(3)The partial factor formats for calculation of the vertical bearing capacity of single pile of lock and dock structures are studied.The reliabilities of pile foundation of ship lock and dock are analyzed based on four existing projects.It shows that the partial factor format for calculating the bearing capacity of single pile in Code for Design of Wharf Structures can be used for the design of pile foundation of dock without reliability reduction.But for ship locks,the resistance partial factor should be multiply by a factor of 1.1 if the partial factor format in the Code for Design of Wharf Structures is used.(4)The calculation methods of bearing capacity of composite pile foundation recommented in design codes and literatures are compared.Based on the outcome of reliability analysis,the partial factors of composite pile foundation of ship lock and dock are proposed.