China's coastal port construction focuses on transportation systems such as coal, containers, imported iron ore, grain, land ro-ro and deep-water sea lanes, especially strengthening the construction of container transportation systems. The government has built a number of deep-water container terminals in Dalian, Tianjin, Qingdao, Shanghai, Ningbo, Xiamen and Shenzhen, laying the foundation for the formation of China container hub port. The construction of coal transportation system has been further strengthened, and a number of coal loading and unloading ship docks have been built. At the same time, a number of imported crude oil and iron ore docks have been rebuilt and expanded. By the end of 2004, there were more than 2,500 intermediate berths in coastal ports, including more than 650 berths of 10,000 tons. In the whole year, the container throughput was 610.5 million TEUs, ranking first in the world. The annual throughput of some big ports exceeds 1 100 million tons, and eight ports including Shanghai Port, Shenzhen Port, Qingdao Port, Tianjin Port, Guangzhou Port, Xiamen Port, Ningbo Port and Dalian Port have entered the top 50 container ports in the world. (From China 2005)
1. A brief history of the port
The most primitive port is a natural port, with natural sheltered bays, inlets, estuaries and other places where ships can park. With the development of commerce and shipping industry, natural ports can no longer meet the needs of economic development, and it is necessary to build artificial ports with docks, breakwaters and loading and unloading equipment, which is the beginning of port engineering construction. /kloc-at the beginning of the 0/9th century, ships powered by steam engines appeared, so the tonnage, scale and draft of ships increased day by day. Modern port engineering construction is developed only after dredgers are needed to build artificial deep-water harbor basins and access channels. Land transportation, especially railway transportation, brings a large number of goods in and out of the port, which greatly promotes the development of port construction.
2. Port classification
2. 1 port can be divided into basic port and non-basic port.
(1) basic port:
This is a port where liner companies usually call at regular intervals. Most of them are large ports located in the center, with good port equipment and stable goods. If it is stipulated as the basic port, the cargo volume will no longer be limited. Generally, the goods delivered to the basic ports are directly transported without transshipment. But sometimes, because the cargo volume is too small, the ship decides to transship midway, and the ship will make its own arrangements and bear the transshipment expenses. Collect freight from the shipper according to the basic port freight rate, and no transshipment surcharge or direct surcharge is allowed. And shall issue a direct bill of lading.
(2) Non-basic ports:
All ports except basic ports are called non-basic ports. Non-base ports generally charge transshipment surcharges in addition to the basic port fees. When a certain amount is reached, it will be changed to direct surcharge. For example, Honiara on the New Guinea route is the basic port of Solomon Islands. Kita port is a non-basic port. A transshipment surcharge of $43.00/ft will be added to the freight of goods shipped to Quetta Port on the basis of Huna freight.
2.2 Classification by purpose
Ports are divided into commercial ports, military ports, fishing ports and safe havens. According to the location, there are estuary ports, seaports and river ports.
(1) Hekou Port
Located at the estuary of the river or the estuary affected by the tide, it can serve both seagoing ships and river ships. Generally, there are big cities as the support, and the land and water transportation is convenient. Inland waterways often go deep into the vast economic hinterland of the mainland and bear a large amount of cargo flow. Therefore, many big ports in the world are built near the estuary, such as Rotterdam, London, new york, Leningrad and Shanghai. The characteristic of Hekou Port is that the wharf facilities are arranged along the river bank, not far from the sea, and there is no need to build breakwater. If the coastline is not long enough, you can dig more harbors.
(2) Harbour
Located on the coast, bay or lagoon, some of which are built in deep water far from the coast. Ports located on the offshore coast or in bays with insufficient natural protection usually need to build breakwaters of considerable scale, such as Dalian Port, Qingdao Port, Lianyungang Port, Keelung Port and Genoa Port in Italy. Single-point or multi-point mooring wharves and island wharves for giant oil tankers or ore carriers belong to undefended offshore seaports, such as Braga Port in Libya and Sidon Port in Lebanon. The lagoon is completely or partially separated by natural sand mouths. After digging canals or widening and deepening waterways, ports can be built on the banks of lagoons, such as Beihai Port in Guangxi. There are also large seaports completely covered by nature, such as Tokyo Port, Hong Kong Port and Sydney Port in Australia.
(3) River ports
Ports located on natural rivers or artificial canals include lakes and reservoirs. Lake port and reservoir port are wide in water surface and sometimes stormy, so they have many similarities with seaports, such as the need to build breakwaters. Ports on large reservoirs such as kuibyshev and Zimryansk in the Soviet Union and small ports on Hongze Lake in China all belong to this category.
3. Port composition
The port consists of land and water, as shown in the figure.
3. 1 waters
It usually includes approach channel, anchorage and harbor basin.
(1) In order to ensure that ships can enter and leave the port safely and conveniently, the approach channel must have sufficient depth and width, and the position, direction and radius of curvature of the bend should be appropriate, so as to avoid strong crosswind, cross flow and serious siltation, and minimize the development and maintenance costs of the channel. When the port is located in the deep water bank, when the natural water depth is sufficient for ships to sail at low tide or low water level, it is not necessary to manually dig the channel, but it is necessary to mark the safest and most convenient route for ships to enter and leave the port. If the above conditions cannot be met and ships are required to enter and leave the port at any time, artificial waterways must be excavated. Artificial channels are divided into unidirectional channels and bidirectional channels. The channel width of large ships is 80 ~ 300 meters, and that of small ships is 50 ~ 60 meters.
(2) Anchorage refers to the waters covered by natural or artificial resources that can withstand strong winds and waves, where ships can anchor, wait for berthing or leave the harbor. If the port lacks deep-water wharf berths, it can also be used for ship-to-ship water loading and unloading operations. River barge teams can also weave, dismantle and change tugs (wheels) here.
(3) Harbor basin refers to the waters directly adjacent to the port land for ships to dock, temporarily dock and turn around. According to the structural form, the harbor basin is divided into open harbor basin, closed harbor basin and dug harbor basin. The scale of the harbor basin should be determined according to the scale of the ship, the way of entering and leaving the dock, the influence of current and wind direction, and the layout of the turning waters. There is no gate or lock in the open harbor basin, and the water level rises and falls with the change of water level. The closed harbor basin is equipped with gates or shiplocks to control the water level, which is suitable for areas with large tidal range. Excavated harbor basins are excavated on the shore, which are mostly used in places with insufficient coastline and suitable terrain conditions.
3.2 Land area
Refers to the land area of the port used for cargo handling, storage, transshipment and passenger distribution. On land, there are land access channels (railways, highways, transportation pipelines, etc. ), the loading and unloading area in front of the wharf and the area behind the port. The frontier loading and unloading operation area is used for the distribution of goods, and warehouses or yards (frontier yards) and waiting halls for fast-moving goods such as railways, highways, loading and unloading machinery and equipment are arranged at the front of the wharf. The rear area of the port is used to arrange railways, roads, warehouses or yards for long-term storage of goods (rear yards), and port ancillary facilities (garages, parking lots, machine repair workshops, tool rooms, substations, fire stations, etc.). ) and administrative and service rooms. In order to reduce the land area of the port, there is no need to set up a rear yard in the port.
4. Port equipment
Onshore equipment includes intermittent loading and unloading machinery and equipment (gantry, tire, automobile, bridge and container cranes, ship unloaders, etc.). ), continuous loading and unloading machinery and equipment (belt conveyor, bucket elevator, compressed air and hydraulic conveying device and pumping station, etc. ), power supply and lighting equipment, communication equipment, water supply and drainage equipment, fire prevention equipment, etc. Inland transportation machinery and equipment include trains, trucks, self-propelled trucks and pipeline transportation equipment. Water loading and unloading transportation machinery and equipment include cranes, tugboats, barges and other port working ships, underwater pipelines, etc.
5. Technical characteristics of the port
It mainly includes the water depth of the port, the number of berths, the length of the dock line and the elevation of the port land area.
5. 1 port water depth
One of the important symbols of the port. Point out the port conditions and the basic restrictions on the availability of ships. Increasing the water depth can accept ships with large draft, but it will increase the dredging volume and increase the cost and maintenance of port hydraulic structures. Under the premise of ensuring the safety of ship driving and berthing, the water depth of each part of the port can be determined separately according to the use requirements, and it is not necessary to be completely consistent. For tidal ports, when the dredging volume of the approach channel is too large, ships can be considered to enter and leave the port by tide. In modern ports, the water depth of large dry cargo seagoing wharf is10 ~15m, and that of large oil tanker wharf is10 ~ 20m.
5.2 Number of berths at the wharf
According to the kind of goods. In addition to the berths needed for loading and unloading goods and getting on and off passengers, there are also berths for auxiliary ships and shiprepair docks.
5.3 Wharf Line Length
According to the safe distance between the captain and the ships that may dock at the same time.
5.4 Port land elevation
According to the design high water level plus superelevation value, it is required that the port area will not be flooded when the water level is high. In order to reduce the project cost and determine the land elevation of the port area, the balance of excavation and filling in the port area should be considered as much as possible. When the port area is expanded or rebuilt, the elevation of the wharf front should be adapted to the elevation of the land behind the original port area, so as to facilitate the operation of roads and railway vehicles. The docks in the same operation area usually adopt the same elevation.
6. Port planning
Port construction involves a wide range, which is related to the construction of nearby railways, highways and cities, and to the industrial layout of the country and the development of industrial and agricultural production. The construction planning of the whole country, especially the coastal ports, must be formulated in accordance with the principles of overall arrangement, rational layout, combination of distance and distance and phased construction. Implement the principle of deep water and shallow water, and rationally develop, utilize or protect the country's port resources. Before planning, we should make a good socio-economic survey of the hinterland of the port, find out the natural conditions for port construction, choose a good port site, and determine a reasonable project scale and overall planning.
Port planning should be closely coordinated with the development planning of the city where it is located. Environmental problems must be considered in an important position in the overall planning, coastal parks and coastal convalescent facilities should be rationally allocated, and pollution to the surrounding environment should be strictly prevented.
6. 1 Port Location
The important steps of port planning, the scope of port economic hinterland, traffic, industrial and agricultural production and mineral deposits, as well as the situation of goods, cargo flow and freight volume, are important basis for determining port location; It is necessary to conduct extensive investigation, research, analysis and demonstration. Natural conditions are the technical basis for determining the port site. Therefore, the areas with conditions to build ports should carry out in-depth investigation and study on port engineering survey, coastal hydrology, meteorology, geology and geomorphology, supplemented by necessary scientific experiments, and then carry out port site selection to make it technically feasible and economically reasonable.
6.2 General layout of the port
The primary work of port engineering design. Its task is to make a reasonable plane layout of various components and engineering facilities in various operation areas, port waters and land areas of the port, so as to make the loading and unloading operation and transportation operation systems, production buildings and auxiliary building systems cooperate and coordinate with each other, so as to improve the comprehensive capacity of the port and reduce the transportation cost.
7. Port hydraulic structures
Generally, it includes breakwater, wharf, ship repair and shipbuilding hydraulic structures. Navigation facilities (navigation marks, lighthouses, etc.). Ships entering and leaving the port and revetment in the port area also belong to the scope of port hydraulic structures. In addition to meeting the general requirements of strength, stiffness, stability (including seismic stability) and settlement, the design of port hydraulic structures should also pay special attention to the influence of dynamic factors such as waves, water flow, sediment and ice on port hydraulic structures and the corrosion of environmental water (mainly seawater) on buildings, and take corresponding measures such as scour prevention, siltation prevention, seepage prevention, wear resistance and corrosion prevention.
7. 1 breakwater
Hydraulic structures located in the periphery of port waters are used to resist wind and waves and ensure a stable water surface in the port. A jetty that protrudes from the water surface and extends to the water area and connects with the shore. An island dike that stands in the water and is not connected to the shore. The water surface outside the dike or between two dikes is called the port entrance. The number and width of ports should meet the requirements of stable water surface and safe and convenient navigation in and out of ports when ships dock and carry out loading and unloading operations. Sometimes, breakwaters are also used to prevent sediments and ice floes from invading ports. The inside of the breakwater usually doubles as a dock.
Breakwater line layout includes single jetty, double jetty, island jetty and mixed type. In order to make the water flow downstream and reduce sediment intrusion into the harbor, the axis of the dike is often arranged in an encircling manner. Breakwater can be divided into sloping type, vertical type, mixed type, permeable type and floating type according to its cross-section shape and its influence on waves, as well as various types equipped with air jet wave-absorbing equipment and water jet wave-absorbing equipment. Generally, the first three types are used:
① Slope breakwater. Commonly used types are rockfill breakwaters and breakwaters with concrete facing blocks on rockfill prisms. Slope dike has low requirements for foundation bearing capacity and can use local materials; The construction is relatively simple, no large lifting equipment is needed, and it is easy to repair after being damaged. The wave breaks on the slope, with slight reflection and good wave-absorbing performance. Generally suitable for soft soil foundation. The disadvantage is that the amount of materials used is large, and stones or artificial blocks are easy to roll off and lose under the action of waves because of their small weight, so they need to be repaired frequently.
② Vertical breakwater. Can be divided into gravity type and pile type. Gravity type generally consists of wall, bed and breast wall. The walls are mostly box caisson structures, which are stabilized by the weight of the building itself. Strong and durable structure, less material consumption. Its inner side can also be used as a wharf, which is suitable for occasions with large waves and water depth and good foundation. The disadvantage is that the wave is reflected in front of the wall and the wave elimination effect is poor. The pile type is generally composed of steel sheet piles or large pipe piles, and blocks are filled between sheet pile wall or behind the wall, which has poor strength and durability and is suitable for poor foundation soil and small waves.
③ Mixed breakwater. Gaoming subgrade is a combination of vertical superstructure and sloping dike foundation, which is suitable for deep water. At present, breakwater construction is developing towards deep water, and caisson structure is mostly used for large-scale deep water breakwaters. There are more and more kinds of artificial blocks used in the lower part of sloping breakwaters and mixed breakwaters, and their wave-absorbing performance is getting better and better.
7.2 Wharf
Hydraulic structures for ships to dock, load and unload goods and get on and off passengers. The vertical wharf is widely used, which is convenient for ships to dock, and the machinery directly drives to the front of the wharf to improve the loading and unloading efficiency. Slope wharf can also be used in areas with large inland water level difference, and barges are arranged in front of the slope road for wharf use; Due to many loading and unloading links, it is difficult for machinery to get close to the front of the wharf, and the loading and unloading efficiency is low. Floating docks can also be used in rivers and lakes with small water level difference and harbor basins covered by nature or man-made, and barges can be connected with the shore through movable approach bridges. This kind of wharf is generally used as auxiliary wharf such as passenger wharf, fish unloading wharf and ferry wharf.
The wharf structure forms include gravity type, high pile type and sheet pile type. Mainly according to the use requirements, natural conditions and construction conditions.
① Gravity wharf. Relying on the self-weight of the building and the weight of the filler within the structure, it is stable, with good structural integrity, firmness and durability, easy to repair after damage, integrally masonry and prefabrication, and suitable for better foundation.
② High-piled wharf. It consists of foundation piles and superstructure. The lower part of the pile is driven into the soil and the upper part is higher than the water surface. The superstructure includes beam-slab type, beam-slab type, frame type and bearing platform type. The high-piled wharf is a permeable structure, and waves and current can pass below the wharf plane, without reflecting waves and affecting flood discharge, and can reduce siltation, so it is suitable for soft soil foundation. In recent years, long piles and long-span structures have been widely used, and large prestressed concrete pipe piles or steel pipe columns have gradually been used to replace piles with smaller sections and become pipe pile docks.
③ Sheet pile wharf. It consists of sheet pile wall and anchorage facilities, which bear the ground load and the lateral pressure caused by backfill behind the wall with the help of sheet piles and anchorage facilities. Sheet pile wharf has simple structure and fast construction speed, and can be used except for particularly hard or too soft foundation, but its structural integrity and durability are poor.
7.3 Ship repair and shipbuilding hydraulic structure
There are slipway type and dock type. The ship to be repaired is towed to the slipway through the slipway, and the underwater part of the hull is launched in the opposite direction after being repaired. The repair and installation of the above-water part of the hull or the replacement of the ship's mechanical equipment are carried out at the ship repairing dock. The newly built ship is assembled and painted on the slipway, and then launched. Ship machinery and equipment are installed on the water part of the ship dock and painted.
The dock is divided into dry dock and floating dock.
① Dry dock. It is an underground hydraulic structure, closed on three sides and equipped with a dock door on one side. After the ship to be repaired is docked, close the dock door, drain the water, repair the underwater part of the hull, and then pour water to float the ship. Open the dock door and let the ship dock. The newly built ship will assemble the hull structure in the dock, paint the underwater part of the hull and install some ship machinery and equipment before leaving the dock, and then proceed to the next step.
② Floating dock. It consists of side walls and the bottom of the dock. When repairing a ship, first fill the dock with water to sink it. After being towed into the ship to be repaired, the dock water is discharged, so that the ship is located at the bottom of the dock to be repaired. The construction of new ships in floating dock is similar to that in dry dock. Floating docks can be parked on the water near the shipyard or towed to other places by tugboats. Both the slipway and dock need a solid foundation to bear the huge pressure of the hull. When building on soft foundation, pile foundation is generally used. When building a large dock on permeable soil, the decompression drainage structure is generally adopted to reduce the groundwater level by driving sheet piles or artificial drainage facilities, so as to reduce the huge buoyancy of groundwater on the dock floor and the lateral pressure on the dock wall when the dock is empty.
8. Port construction
Port engineering construction is similar to other civil engineering in many places, but it has its own characteristics. Port projects are often built on the sea with deep waves or rivers with large water level fluctuations, which require large quantities of water works, high quality and short construction period. Some seaports have also been hit by typhoons or other storms. Therefore, it is required to adopt the engineering construction scheme with high assembly and fast construction speed as far as possible to shorten the water operation time as much as possible. And take practical measures to ensure the stability of the building during construction and prevent landslides or other forms of damage. Due to improper construction methods or insufficient understanding of the mechanism and destructiveness of storms and ineffective measures, cases of building damage during construction occur from time to time and should be used for reference.