EXPERIENCE TO DESIGN STRUCTURE FOR JETTY (PORT, HARBOR)
The most important to design structure for Jetty (Port, Harbor) - The waterway project is determined the distance between the central from pile to pile. The next step to be determined dimension of beams and shape of structure elements for jetty (port, harbor). Underneath are some experience of designer would like to share the knowelge to do determine primary dimensions of jetty (port, harbor).
Distance of central lines between pile to pile:
Distance between pile to pile of rows, columns to consump clashing force of vessel to jetty (port, harbor) => Distance between fenders, based on this force to determine the distance between pile to pile, and dimensions of beam.
Summarize for those steps as below:
1. Computerize Clashing force of vessel to jetty (port, harbor)
2. Determine distance between fender
3. Determine central lines between piles or 1/2 distance between fenders (The arrangement of fenders is located on longtitudinal beam at piles location)
4. Dimensions of beam, distance between beams and shape of structural elements for waterway project.
Notes to select primary distance for structures:
1. Minimum distance between piles rows, cloumns should be longer than (3÷5)D - D is diameter of spun pile and square pile is applied for the friction force of surface pile.
2. The pile length should be stand on the firmed layer as stone layer or weathered stone layer, the minimum distance can be determined equal 2D. (Standard 205-1998: Design spun pile foundation)
The pile length:
Based on the Soil investigation to determine the primary pile length of jetty (port, harbor), depend on the SPT of each layer on the Soil Investigation documents, we can estimate the primary pile length for computerization whereif N > 30 in the clay layer, N > 40 in the sand layer.
Diameter of spun pile:
Based on the primary pile length (L) to be determine as above, the diameter is equal on formular L/D = (60÷90) comply with capacity of meterial.
Notes: the Bridge structure computation experienced, we can simpfly the longitudinal beams because the major forcced on the horizonal only.
Picture 1: Layout of typical bridge segment.
Experience to do segement of bridge as below:
We can divide jetty segment as formular below:
L=(2÷3)B
With:
L: the length of segment, (m)
B: the width of segment, (m)
The important note: the width's gap between segment ~ 2cm with function is temporature expansion and settlement unequavelance between segments.
Experience to determine the high of beam:
Based on standards mention the hight of beam as below:
h/L=(1/8÷1/12)
With:
L: the length of beam, (m)
h: the hight of beam, (m)
