Study On Calculation Methods Of Pontoon Wharf Mooring Force In Inland River

In recent years, with the improvement of the Yangtze river upstream channelcondition, ship large-scale trend is obvious, existing pontoon wharf berthing is1000-3000tons, now which need to berth3000-5000tons ship, pontoon wharf berthingcapacity requirements more and more high, so pontoon mooring force calculation isvery important. In allusion to the present pontoon wharf mooring force calculationproblem, this paper adopt dynamic test signal system for testing pontoon wharf mooringforce, on the basis of this testing the experiment,which respectively applied on "loadcode for the design of port engineering", OPTIMOORT calculation method and theMIDAS finite element analysis method for accumulating mooring force, get through thecomprehensive analysis and put forward some suitable calculation method on inlandpontoon wharf mooring force. Then the influence factors of pontoon wharf mooringforce were analyzed, and reach (a conclusion) which pontoon wharf with the changingrule of the influence factors. Specific research and research results are as follows:(1)Combined with the slope pontoon wharf characteristicses of Chongqing jiulongpoport1, making pontoon mooring force field test plan, using Jiangsu Donghua testdynamic sigal test system DH5922,and according to the principle of the cable forcecalculation, conduct to field test on pontoon wharf mooring force. Measure the pontooneight mooring cable frequency and calculate the mooring force of each cable.bydynamic signal test system.(2)On the basis of this testing the experiment, which respectively apply on "loadcode for the design of port engineering", OPTIMOORT calculation method and theMIDAS finite element analysis method for accumulating mooring force, and comparingwith the field measured data, the results show that: the"load code for the design of portengineering" cannot calculate for every force of the cable, but which can calculate thewind and water forces acting on the pontoon; The mooring force result of MIDAS finiteelement method is close to the measured value; OPTIMOOR software method isapplicable to calculate the ship’s mooring force in general.(3) Analysis the main factors of influencing the pontoon wharf mooring force, andthrough finite element calculation, respectively draw the water level, water flow, windload of three main influence factors for the influence and regularity of pontoon wharfmooring force. Results show that: When the angle between the pontoon’s longitudinal axial and current is1~15degree, the mooring force stress values of upper transverseline, lower transverse line and stern line is slants large than in the longitudinal axialflow and pontoon parallel, the stress values of the head line and territorial water anchoris relatively small; Under the condition of wind blowing, the pontoon mooring forcenumerical value of upper transverse line and lower transverse line is bigger, and in theapproach under the condition of wind, blowing outside anchor upstream anddownstream outside anchor value is larger; With the increasing of berthing ship’stonnage, each location mooring force of pontoon wharf also increases.(4)Using the single factor sensitivity analysis method to analyze three differentinfluence factors on each position degree of sensitivity of pontoon mooring force.Results show that: when changing the velocity speed, sensitivity order is: territorialwaters anchor> head line> upper transverse line> lower transverse line> stern line；when changing the wind speed，sensitivity order is: stern line> upper transverse line>lower transverse line> territorial waters anchor> head line; when changing the berthingships tonnage, sensitivity order is: stern line> upper transverse line> lower transverseline> head line> territorial waters anchor.