Method for lowering a basement structure

A method for lowering a basement structure includes forming several upright pile holes in the ground, providing each of the pile holes with a pile, providing several vertical guide holes and an excavation passage which are formed through the basement structure in such a manner that the guide holes are aligned with the pile holes, equipping each of the guide holes with an impelling device which is coupled with one of the piles, excavating soil below the basement structure, and activating the impelling devices to lower the basement structure into the ground in such a manner that the piles extend through the guide holes. Several vertical steel rods are embedded in each of the piles. Each of the impelling devices includes an upright cylinder body fixed on the top end of the basement structure, a piston rod extending through the cylinder body, and a piston carried on the piston rod. An internally threaded engaging member is engaged with the externally threaded lower portion of the piston rod. Several coupling bar units interconnect securely the engaging member and the upper ends of the steel rods. Each of the coupling bar units includes several bar sections arranged in a line and several collars detachably interconnecting the bar sections. A rotary lever unit is secured to the piston rod.

BACKGROUND OF THE INVENTION 
1. Field of the Invention 
This invention relates to a method for constructing a basement in the 
ground, more particularly to a method for lowering a prefabricated 
basement structure into the ground which can maintain the vertical descent 
of the basement structure during the lowering process. 
2. Description of the Related Art 
Because a prefabricated basement structure is lowered into the ground by 
the pull of gravity, it is very heavy, so if it is tilted during its 
lowering process, it is difficult to place the basement structure in a 
substantially vertical position when the basement structure reaches the 
predetermined position in the ground. In U.S. Pat. Nos. 4,938,634 and 
5,004,375, the applicant disclosed two improved basement structure 
lowering methods which can keep the vertical descent of the basement 
structure. The applicant now tries another approach thereto. 
SUMMARY OF THE INVENTION 
It is therefore the main object of this invention to provide a method for 
lowering a prefabricated basement structure into the ground which can 
maintain the levelness of the basement structure while lowering the same. 
According to this invention, a method for lowering a basement structure 
includes forming several upright pile holes in the ground, providing each 
of the pile holes with a pile, providing several vertical guide holes and 
an excavation passage which are formed through the basement structure in 
such a manner that the guide holes are aligned with the pile holes, 
equipping each of the guide holes with an impelling device which is 
coupled with one of the piles, excavating soil below the basement 
structure, and activating the impelling devices to lower the basement 
structure into the ground in such a manner that the piles extend through 
the guide holes. Several vertical steel rods are embedded in each of the 
piles. Each of the impelling device includes an upright cylinder body 
fixed on the top end of the basement structure, a piston rod extending 
through the cylinder body, and a piston carried on the piston rod. An 
internally threaded engaging member is engaged with the externally 
threaded lower portion of the piston rod. Several coupling bar units 
interconnect securely the engaging member and the upper ends of the steel 
rods. Each of the coupling bar units includes several bar sections 
arranged in a line and several collars detachably interconnecting the bar 
sections. A rotary lever unit is secured to the piston rod and can be 
rotated to move the piston rod vertically.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT 
Referring to FIG. 1, a method for lowering a prefabricated basement 
structure (3) into the ground (1) has a first step of drilling into the 
ground (1) to form several upright pile holes (2) in the region in which 
the basement is to be installed. A soil stabilizing agent is applied to 
the peripheral walls o f the pile holes (2) so as to maintain the shape 
and size of the pile holes (2) in the ground (1). Each of the pile holes 
(2) is formed with an enlarged lower end portion (21) in a known manner. 
The second step is to provide each of the pile holes (2) with a 
poured-concrete pile (23) which is divided into two substeps. The first 
substep is to place several annularly arranged vertical steel rods (22) in 
each of the pile holes (2). Next, a cement material is poured into the 
pile holes (2) to constitute poured-concrete piles (23). The rods (22) 
including the portions that extend above the concrete, as shown in FIG. 1, 
become a component of the piles. 
The third step is to provide several vertical guide holes (36) and an 
excavation passage (35) which are formed through the basement structure 
(3), wherein the guide holes (36) are aligned with the pile holes (2). The 
excavation passage (35) and each of the guide holes (36) have three 
sections which are formed in the basement floors (34). The basement 
structure (3) further has an outward flange (32) (see FIG. 1) projecting 
outward from the bottom end thereof, four corner ribs (R) (see FIG. 3) 
projecting outward from the peripheral walls of the basement structure 
(3), and an inclined inner surface (39) disposed at the bottom end of the 
basement structure (3) so as to prevent the piles (23) from hindering the 
downward movement of the basement structure (3). The outward flange (32) 
and the corner ribs (R) together define four agent accommodating spaces 
(33) in the basement structure (3). An annular guide body (37) is provided 
on the ground and surrounds the basement structure (3). 
The fourth step is to equip each of the guide holes (36) with an impelling 
device (4) which is coupled with one of the piles (23). Referring to FIGS. 
4, 5 and 6, each of the impelling devices (4) includes an upright 
hydraulic cylinder body (41), a piston rod (42), a piston (P) (see FIG. 
7), an internally threaded engaging member (44), and several coupling bar 
units (45). The cylinder body (41) is fixed on the top surface of the 
basement structure (3). The piston rod (42) extends through the piston 
body (41) and has a central bore (421) through which a central rod (43) 
extends. The central rod (43) has an externally threaded lower portion 
(431) which is engaged within the engaging member (44). A horizontal 
rotary lever unit (432) is secured to the upper end of the central rod 
(43) so that the rotation of the rotary lever unit (432) moves the piston 
rod (42) and the central rod (43) vertically relative to the engaging 
member (44). The piston (P) is sleeved rigidly on the piston rod (42) and 
is received slidably in the cylinder body (41). A nut member (433) is 
engaged threadably with the lower end portion of the central rod (43) and 
is positioned within the enlarged lower end portion of the threaded 
central bore of the engaging member (44). The piston rod (42) and the 
rotary lever unit (432) have curved interengaging surfaces (434) so as to 
obtain firm connection therebetween. Likewise, the upper end portion of 
the nut member (433) and the engaging member (44) have curved 
interengaging surfaces (435) so as to obtain firm connection therebetween. 
Each of the several bar units (45) includes several vertical bar sections 
(47) arranged in a line. Each adjacent pair of the bar sections (47) are 
detachably interconnected by a collar (46). The uppermost bar sections 
(47) are connected securely to the engaging member (44). The lowermost bar 
sections (47) are connected securely to the upper ends of the steel rods 
(22). 
The fifth step is mechanical excavation of soil below the basement 
structure (3) through the excavation passage (35) of the basement 
structure (3). 
The sixth step is to activate the impelling devices (4) to help lower the 
basement structure (3) into the ground by gravity in such a manner that 
the piles (23) extend through the guide holes (36) of the basement 
structure (3). Referring to FIG. 5, when a hydraulic liquid is introduced 
into the cylinder bodies (41) below the pistons (P), the pistons (P) and 
the piston rods (42) are moved upward in the cylinder bodies (41) so that 
the rotary lever units (432) impel the cylinder bodies (41) and the 
basement structure (3) to move downward. When the pistons (P) reach their 
uppermost positions in the piston bodies (41), the hydraulic liquid in the 
cylinder bodies (41) is removed from below the pistons (P) so as to move 
the pistons (P) to their lowermost positions in the piston bodies (41). 
Afterwards, as shown in FIG. 7, the rotary lever units (432) are actuated 
to move the piston rods (42) and the central rods (43) downward. During 
the downward movement of the piston rods (42) and the central rods (43), 
it is necessary to intermittently remove the uppermost bar sections (47) 
from the rest of the coupling bar units (45) so as to prevent the basement 
structure (3) from engagement with the upper ends of the coupling bar 
units (45). In this way, the basement structure (3) can be lowered to the 
predetermined position shown in FIG. 8. It is understood that the 
engagement of the piles (23) with the guide holes (36) maintains the 
levelness of the basement structure (3) during lowering of the same. A 
soil stabilizing agent is applied to the agent accommodating spaces (33) 
between the basement structure (3) and the ground during the lowering of 
the basement structure (3). 
Referring to FIG. 9, the seventh step is to replace the soil stabilizing 
agent in the agent accommodating spaces (33) with a cement material. The 
eighth step is to cut the upper portions of the steel rods (22) and the 
piles (23), which extend into the basement structure. The ninth step is to 
provide the basement structure (3) with a ground floor (38) which defines 
a reservoir accommodating space (31) in the bottom end portion of the 
basement structure (3). The tenth step is to pour a cement material into 
the sections of the guide holes (36). The eleventh step is to provide 
three concrete layers to close the upper ends of the sections of the 
excavation passage (35). Finally, the annular guide body (37) is removed 
from the basement structure (3). 
Because the piston rod (42) is carried on the central rod (43), the 
externally threaded lower portion (431) of the central rod (43) may be 
regarded as an extension of the piston rod (42). 
With this invention thus explained, it is apparent that numerous 
modifications and variations can be made without departing from the scope 
of this invention. It is therefore intended that this invention be limited 
only as indicated in the appended claims.