Special-shaped rammer for pile forming

Abstract

The utility model relates to a special-shaped rammer for pile forming, which is characterized in that the rammer is composed of an upper hammer head and a lower hammer rod, the upper hammer head is in a large-diameter column shape, and the lower hammer rod is a small-diameter steel pipe with a closed bottom end or a solid flat-bottom steel column. The upper hammer head and the lower hammer rod are welded or quickly connected into a whole by adopting one of a bolt, a screw thread and a threaded outer sleeve; the diameter and the length of the lower hammer rod are matched according to a prefabricated pipe pile or a wall protection steel pipe used in actual construction, the diameter of the lower hammer rod is required to be smaller than the diameter of a center hole of the prefabricated pipe pile or the inner diameter of the wall protection steel pipe by more than 3cm, and the length of the lower hammer rod is required to be larger than the length of the prefabricated pipe pile or the wall protection steel pipe.

Description

Technical Field

[0001] The invention relates to equipment for foundation pile construction, in particular to a special-shaped rammer for pile formation. Background Art

[0002] In the process of various engineering construction, foundation construction is the most basic and most crucial link. With the continuous expansion of construction scale and the continuous improvement of construction technology, the requirements for pile foundations of buildings have also changed greatly, mainly manifested in the increasingly high requirements for the bearing capacity of the foundation and the increasingly wide requirements for applicability to various complex geological conditions.

[0003] Carrier pile technology is a pile foundation construction technology developed in recent years. The earliest construction technology disclosed in the patent document No. ZL98101041.5 is to use construction waste, concrete fragments, dry hard concrete, etc. as filling materials, and to perform filling, compaction, and compaction operations at the bottom of the pile to form an artificial bearing layer to transfer the upper load, thereby improving the bearing capacity of the pile. The invention and innovation of carrier pile technology has been widely used in the field of construction engineering and has created relatively significant social and economic benefits. However, in recent years' engineering practice and application, with the continuous increase in the volume of buildings and structures, the requirements for pile foundation bearing capacity have become higher and higher. It is often required that the ultimate load of a single pile reach more than 5000kN, and the highest has reached 12000kN. Under such high bearing capacity requirements, the construction process and quality requirements of carrier piles are also more stringent. At present, the most commonly used heavy hammer for carrier piles in cast-in-place pile bodies is a 3.5-ton heavy hammer. The weight of the heavy hammer used in prefabricated pipe piles is even smaller, generally 2-3 tons. In many tests and constructions, it was found that when using a heavy hammer of this weight for construction, when tamping the filler in a good soil layer, it is easy to have a small amount of filler and quickly reach the three-hit penetration control requirements. However, in subsequent tests, it was found that the bearing capacity of the pile was not high, which was inconsistent with the theoretical bearing capacity corresponding to the three-hit penetration. After searching for the cause in many ways, it was found that the weight of the tamping tool was not enough, and the tamping energy generated was relatively small, which could not completely overcome the resistance of the soil at the pile end itself. The resistance was greater when tamping the filler, so the filler amount was small and failed to form a good compaction effect, but it was easy to meet the penetration requirements. This "penetration standard" is not a real standard, and it actually does not meet the bearing capacity corresponding to the penetration standard. At the same time, when tamping the filler in a relatively weak soil layer, it is easy to have a large number of tamping times and a large amount of filler but still fail to meet the three-hit penetration standard. Sometimes, even the amount of filler reaches 2 cubic meters, but the penetration rate still cannot meet the standard. The reason for this situation is that the tamping energy is relatively small, so the number of tamping times has to be increased. However, the more tamping times, the greater the disturbance to the soil at the pile end, and the soil is compacted into rubber soil, which loses its original bearing capacity, causing the construction to fail.

[0004] Now, people have recognized the above-mentioned problems of carrier piles and similar structural piles. Because the hammer weight and tamping energy do limit and affect the promotion and application of technology, further research and development are needed to ensure project quality, improve efficiency, save costs, and be suitable for various types of engineering applications. Utility Model Content

[0005] The utility model designs a special-shaped rammer for pile formation, characterized in that the rammer consists of two parts, an upper hammer head and a lower hammer rod, the upper hammer head is a large-diameter column, the lower hammer rod is a small-diameter tube with a closed bottom or a solid flat-bottomed steel column, the upper hammer head and the lower hammer rod are welded or quickly connected as a whole by means of bolts, threads, or threaded outer sleeves; the diameter and length of the lower hammer rod are adapted according to the prefabricated pipe piles or wall protection steel pipes used in actual construction, the diameter of the lower hammer rod is required to be less than the center hole diameter of the prefabricated pipe pile or the inner diameter of the wall protection steel pipe by more than 3 cm, and the length of the lower hammer rod is required to be greater than the length of the prefabricated pipe pile or the wall protection steel pipe.

[0006] Preferably, the upper hammer head is in the shape of a cylinder, a square column or a polygonal column; the two sides of the upper hammer head are provided with guide arms or guide grooves for connecting to the vertical bracket of the pile driver; the top center of the upper hammer head is provided with a hanging point for connecting to the lifting device of the pile driver. During construction, the lower hammer rod of the special-shaped rammer passes through the center hole of the prefabricated pipe pile or the inner cavity of the wall-protecting steel pipe. After the special-shaped rammer is lifted to a certain height by the pile driver lifting device, the special-shaped rammer performs free fall along the vertical bracket of the pile driver, the upper hammer head generates the main ramming energy above the prefabricated pipe pile or the wall-protecting steel pipe, and the bottom end of the lower hammer rod generates impact force.

[0007] Preferably, the upper hammer head and the lower hammer rod of the special-shaped rammer are connected by means of bolts, threads, snaps, and threaded outer sleeves, and can be quickly assembled and disassembled during construction.

[0008] Preferably, when the lower hammer rod is a thick-walled steel pipe with a small diameter and a closed bottom end, lead, steel slag, stone powder, crushed stone, sand, concrete or mortar can be poured into the steel pipe.

[0009] Preferably, the lower hammer rod adopts a single steel pipe or a single steel column, or adopts a quick combination of multiple steel pipes or steel columns depending on the length requirement.

[0010] The characteristics and advantages of this special-shaped rammer for pile formation are that, under the condition of being applicable to the construction methods and characteristics of carrier piles and similar rammed and expanded piles, without changing the pile type specifications and construction equipment, the quality of the rammer is significantly improved, so that greater ramming energy can be obtained during construction, and the compaction effect is significantly improved. At the same time, it is quick to transport and install, easy to assemble and disassemble, and provides more solutions with different hammer weights and hammer diameter combinations to meet the specific needs of different projects. BRIEF DESCRIPTION OF THE DRAWINGS

[0011] Figure 1 is a front view of an embodiment of a special-shaped rammer for pile formation;

[0012] Figure 1 In the figure, 1-upper hammer head, 2-lower hammer rod, 3-connecting plate, 4-connecting buckle, 5-guide arm, 6-hanging point, 7-prefabricated pipe pile. DETAILED DESCRIPTION

[0013] A special-shaped rammer for pile formation, consisting of an upper hammer head 1 and a lower hammer rod 2. The upper hammer head is a round steel column with a diameter of 500 mm, a height of 3 m, and a weight of 4.6 t. The diameter and length of the lower hammer rod 2 are adapted according to the prefabricated pipe piles or wall protection steel pipes used in actual construction. In this embodiment, a prefabricated pipe pile 7 with a center hole inner diameter of 400 mm and a length of 12 m is used. Therefore, the specifications of the lower hammer rod 2 are 355 mm in diameter, 13 m in length, and 2.5 t in weight. The entire special-shaped rammer The total weight is 7.1t; a connecting plate 3 with a diameter of 500mm is respectively provided at the lower end of the upper hammer head 1 and the top end of the lower hammer rod 2, and two symmetrical 7-shaped movable connecting buckles 4 are also provided at the top end of the lower hammer rod 2, which can quickly connect the two connecting plates 3 into one and can be quickly disassembled; guide arms 5 are provided on the two sides of the upper hammer head 1, which are used to connect the vertical bracket of the pile driver to play a guiding and straightening role, and a hanging point 6 is provided at the top center position of the upper hammer head 1, which is used to connect the lifting device of the pile driver.

Claims

1. A special-shaped rammer for pile forming, characterized in that: The rammer consists of an upper hammer head and a lower hammer rod. The upper hammer head is a large-diameter column, and the lower hammer rod is a small-diameter tube with a closed bottom or a solid flat-bottomed steel column. The upper hammer head and the lower hammer rod are welded or quickly connected into one by one of bolts, threads, snaps, and threaded outer sleeves. The diameter and length of the lower hammer rod are adapted according to the prefabricated pipe piles or wall protection steel pipes used in actual construction, and its diameter is required to be smaller than the center hole diameter of the prefabricated pipe pile or the inner diameter of the wall protection steel pipe by more than 3 cm, and its length is required to be greater than the length of the prefabricated pipe pile or the wall protection steel pipe.

2. The special-shaped rammer for pile formation according to claim 1, characterized in that: The shape of the upper hammer head is cylindrical, square or polygonal; guide arms or guide grooves are provided on the two sides of the upper hammer head for connecting to the vertical bracket of the pile driver, and a hanging point is provided at the top center of the upper hammer head for connecting to the lifting device of the pile driver.

3. The special-shaped rammer for pile formation according to claim 1, characterized in that: The upper hammer head and the lower hammer rod of the special-shaped rammer are connected by means of bolts, threads, or threaded outer sleeves, and can be quickly assembled and disassembled during construction.

4. The special-shaped rammer for pile formation according to claim 1, characterized in that: When the lower hammer rod is a thick-walled steel pipe with a small diameter and a closed bottom, lead, steel slag, stone powder, crushed stone, sand, concrete or mortar can be poured into the steel pipe.

5. The special-shaped rammer for pile formation according to claim 1, characterized in that: The lower hammer rod may be made of a single steel pipe or a single steel column, or a quick combination of multiple steel pipes or steel columns, depending on the length requirement.

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