| |
Foundation construction technique |
| During the construction of the foundation for the works of harbor, road & bridge, building, air-port, our company in recent years, taking some typical works as the representatives, successfully applied many kinds of techniques. |
1, Method of pre-compaction drainage for the foundation treatment in the large area
In the middle of 80th, the new technique of strengthening the foundation by vacuum pre-compaction that was developed by our company, was firstly succeeded in the application for the execution of the work of tianjin Port. This has filled the domestic blank and also being in a leading position and acquired national patent, won the first prize of grand achievement of science & technique and national ＾sixfive￣ tackling key problem as well. Our company has also applied for anther two patents; i.e. pontoon pile driver & pile casing device. At present, this foundation treatment method has been being widely used. The accumulative total size of the foundation treatment construction with this method that our company carried out has reached more than 1000m2. |
2. Hard driving method for the foundation strengthening treatment
In the construction of the phase 1 work of the Chaofeidiang ore quay of Huanghua Port, facing the soft sand foundation formed by reclamation, our company used 36 hard driving machineries, spending 5 months, successfully completed 120m2 foundation treatment by hard driving method.
After being tested, the uniform index of the load is bigger than 25t/m2, complied with the design and work duration requirement. Our company has also applied this method in the construction of the following works:
Work of phase 3 of the berths 1 & 2of Qianwan,Qingdao
Work of stockpile yard of phase 3 & 4 of Bayuquan port, Yingkou
Work of plane parking area of Yanliang air port Xian
At present, the accumulative total size of the treated foundation by this method is up to 3200000 m2.
|
3. The method of the formation of the compound foundation
The method of the compound foundation treatment is formed through filling the corresponding material into the reinforced soil to change the soil configuration so as to make it hardened or becoming a kind of reinforced object and this reinforced object with the foundation soil around will together bear the load. For example: method of vibrating sand, method of sand & stone pile, method of CFG pile, method of mixing cement in the deep ground, method of soil & concrete pile compaction and method of high pressure spurting concrete etc. In the construction, the different treatment method would be selected according to the special earth condition and its special requirement of the load so as to meet the corresponding requirement. As the filling material is different, so the method selected is also different. By filling sand & stone into the soil to change the soil and get the efficiency of compaction, to realize the aim of heightening the capacity of load. By filling cement or mortar into the soil or coal powder and chemical liquid into the soil to make the filling material and soil to be chemically reacted, agglomerating, gluing and solidifying so as to heighten the capacity of load.
Up to now, the accumulative total reinforced area by this treatment method in the construction of harbor, road air port and civil works is up to 1000000m2.
|
4. Construction of pile foundation
In resent years, our company carried out the construction of many kinds of pile foundation in the works of harbor, road & bridge, civil works etc.
In the field of drilling-hole concrete pile, our company applied the method of big diagram drilling concrete pile protected by the muddy as the protecting wall. In the construction of interchanging at Tianjin jiefangnanlu, 776 piles were driven, the diameter of the pile is respectively 100cm,120cm,and 150cm, the length of the pile is 35-59, all these piles were driven mainly by the method of drilling hole method. In the construction of Jing-Hu express way, this method was also applied, the diameter of the pile is 1,7m and the length is 68m. up to now, the total length of thios kind of pile driven is up to 150000 meters. In the construction of Nanjiang bridge, long casing concrete pile construction was firstly adoptedon the platform on water erected by the steel structure. In addition, this method is also widely used in the construction of harbor & civil works.
In the field of steel pile construction, it is mainly used by our company in the construction of harbor, bridge, high building or heavy workshop. In the construction of dump engine workshop of nanjiang and circle pumping station of Huanghua power plant, 142 steel piles of diameter 700, 800, the longest pile is 36 meter. In the construction of outlet of the power plant of Huanghua, 276 piles were driven in the water, realized the first breach od piling in the water. This made a very good basis for our company to be involved in the construction of the harbor works. |
5. Construction of earth-wall connection
In the construction of the ground earth-wall connection of Jinhuang high building in Tianjin, the workmanship of forming the trench by hydraulic pressure was adopted. Wall thickness is 800mm, the biggest trench section is 7,2m and cast concrete 9100m3. In the construction of the harbors in resent years, our company contracted dump-engine house of Tianjin port; phase 1 & 2 dump-engine house of Huanghua port; dump-engine house of Nanjiang port of tianjin and large foundation work of water pump station of guohua power plant of huanghua, the above mentioned workmanship was successfully applied, having solved a problem of the construction of earth-wall connection at soft soil area. |
