1. Field of the Invention
The present invention relates to an underground continuous wall job practice applying into soft base anti-seepage, and meanwhile involves to its special drill.
2. Description of Prior Art
In accordance with the conventional underground continuous walls, most of them are used for anti-seeping in foundation of dams, basements, harbor and sluice gate base or both banks of rivers and so on. The job practice is to excavate a trench in the job location firstly, then to pour concrete to construct a continuous proof-water wall in the pit. In this way, too much earthmoving has to be processed in the construction procedure, and too much the concrete is used, the time limit of project is too long and the production cost is very high. And once encountering with groundwater or complex geological structure, the sidewalls of said trench couldn""t be kept in standing so that the construction difficult is increased. If utilizing steel sheet wall or prefabricated concrete plate pile and so on, the investment cost will double and redouble, the anti-seepage effect is also not good as expected. A rapid construction method of concrete shell pile in soft basement and its special drill disclosed in Chinese Patent No.98113070.4 provides a way of constructing a single pile, but not constructing a continuous wall underground conveniently and economically.
It is therefore a main object of the present invention to provide a rapid and economic construction way to build an underground shell-pile continuous wall to have better expected anti-seeping effect, meanwhile to provide a special drill for carrying out this job practice.
This object is achieved by a job-practice adapting cluster of shell-piles to build an underground wall. Follows steps carry out said job practice:
1. Attach a circular pile shoe having cutting faces on the bottom end of the barrel core space of each special-drill building cluster of shell-piles.
2. Locate the first special drill on the job position vertically standing on said pile shoe, and exert pressure on the vibrating head at the tip end of said special drill to press said special drill sinking into the ground to get the desired depth in the soft soil layer, the expelled soil is driven out along the inside wall of inner draining hole of said special drill.
3. Locate and connect the second special drill with the first special drill by coupling the male connector of the second special drill to the female connector of the first special drill, and process the second special drill as described in step 2 to sink into the desired depth.
4. Pour the concrete from the loading hopper of the first special drill, vibrate said special drill as pouring, and withdraw up said special drill simultaneously to depart said pile shoe from the drill trunk until the first special drill is dragged out from the ground completely to build the first shell pile.
5. Put on a new pile shoe on the used first special drill or prepare the third special drill, repeat the step 3 to locate and connect the new special drill to the second special drill, and sink into the designed depth.
6. Repeat the step 4 to withdraw the second special drill, meanwhile build the second clustering shell pile with the first one.
7. In the same way, repeat the circular steps until to build enough many shell-piles to construct an underground continuous wall.
For archiving above-described job practice, said special drill is designed to comprise of a pair of centered an inner sleeve and an outer sleeve, a barrel core space formed between the outside wall of said inner sleeve and the inside wall of said outer sleeve, and a circular pile shoe fitted into the ring opening at the bottom side of said barrel core space, and a flange retained on the top ends of said inner and outer sleeves, and a vibrating head attached on the top side of said flange; said vibrating head has a draining hole connecting to the inner cave of said inner sleeve, and a loading hopper set upon the outside wall of said outer sleeve approaching the top end connecting to the barrel core space, and a pair of male connecter and female connector are fixed on the outside wall of said outer sleeve axially and parallelly, and their including angle to the central axial should be not less than 60xc2x0.
Due to applying this job practice, less earthmoving is processed during the construction procedure, less concrete is needed, it can be used for pouring and building an underground continuous shell-pile wall in the real time at the work site, so that the time limit of project is shortcut, and the cost is reduced, and a better anti-seepage effect is archived.
Said special drill provided in the present invention has a simple structure; by rapid connecting and locating male and female connectors fixed on said special drill, conjunction of shell-pile is became into easy. Draining the expelled soil can be processed as sinking the special drill so that the sinking drag turbine is less, and earthmoving is less too.