Tetrapod

テトラポッド次元

Tetrapod was developed in France in the 1950s and spread around the world. Its development can be traced back to a military fortress during world war ii. Specifically, it is a combination of four cylinders with the center of gravity of a tetrahedron as the intersection point and the four vertices of a tetrahedron as the vertices. By changing the diameter and length of the cylinder, it can be freely made into a concrete tetrapod from 3 ton to tens of ton; according to the purpose and block size, the block body can be used to increase the block bending strength and shear strength. Can be strengthened. In general, like the diameter of the four cylinders at the intersection of the appropriate increase, the block should not be broken.

Application design

Concrete designed with a tetrahedron with a low center of gravity is highly stable and avoids tetrahedrons because the floor surface is unstable due to uneven surfaces. In addition, the streamlined appearance can reduce the impact of water flow on the block itself. The void rate of a tetrapod reaches 50%, which is about 10% higher than that of a block, saving about 20% of material in the same volume. The roughness of the energy dissipation effect of the function is obvious. It was chewy. Overall stability is further improved. The production process is relatively simple and convenient for construction.

feature

The concrete tetrapod has its own advantages in the moisture-proof dog dog.

The geometric structure of a concrete tetrapod determines its stability. No matter where the block rotates, the three pillars touch the pillar and the ground, and the center of gravity is low and the body is stable.

2. In the combination of multiple blocks, the combination between blocks is stable. This combination should not only be reflected on the plane, but also in the three-dimensional stable combination, forming a good stability, and should not be dispersed, the combination has elasticity, and the deformation of the seabed or sand bed can also be well adapted.

3. To make concrete into a tetrapod, it has sufficient erosion and corrosion resistance by selecting the appropriate cement and mixture.

4. The concrete tetrapod is prefabricated on the coast, transported and lifted to the destination. Influenced by seawater and wind waves. The combination of many blocks has a large porosity, can absorb the wave energy well, and has a good wave removal effect.

Application scenario

There are three types of applications for wet berm.

(1) the foot of the dam near the opposite side of the seawall or the dam itself is a part of the complex dam itself. In this case, the arrangement method of the tetrapod down the slope to the lower m5c opening leg, down the slope of another system two legs, deep connection to the replacement arrangement, the upper layer of the opponent is placed in the void.

(2) apart from the coastal protection project, placed in the sea of concrete tetrapods or independent release embankment consisting of ripples.

(3) the DAMS are vertical or sloping, with one end connected to the dam and the other extended to the sea diversion dam.

Concrete tetrappods are rarely used in port breakwaters or coastal engineering. Widely used on the long coastline of the east coast of Japan. The pier of sendai port is an upright concrete breakwater with a width of 6 meters. The breakwater side is to rely on reinforced concrete tetrapod thrown on the breakwater berm. The top of the concrete tetrapod is near the top of the dam and has been hit by Pacific winds and waves for nearly 20 years, but it is still as strong as before. On the arahama coast in miyagi prefecture, Japan, concrete slab breakwater has been set up on the coast. 100 meters offshore, there is a 5km long sea breakwater composed of concrete tetra ods. Due to the influence of the breakwater on the waves, the weak concrete slope protective fence on the coast can withstand the storm surge of more than a dozen or twenty times a year.