CN101798810A

CN101798810A - Cement-soil composite pile inserted into reinforced concrete core materials

Info

Publication number: CN101798810A
Application number: CN 200910046398
Authority: CN
Inventors: 刘全林; 宋伟民
Original assignee: Shanghai Qiangjin Foundation Engineering Co Ltd
Current assignee: Shanghai Qiangjin Foundation Engineering Co Ltd
Priority date: 2009-02-20
Filing date: 2009-02-20
Publication date: 2010-08-11

Abstract

The invention relates to a cement-soil composite pile inserted into reinforced concrete core materials. The cement-soil composite pile is a novel composite pile which is formed by inserting a prestressed concrete tubular pile or a prestressed concrete square pile or a reinforced concrete member, serving as a core material, into a deeply-stirred cement-soil pile (which is formed by deeply stirring through a single-shaft, double-shaft or three-shaft stirring pile machine). The cement-soil composite pile consists of a cement-soil stirring pile and a high-strength core pile. The cement-soil composite pile is formed by the following steps of: stirring soil and cement slurry to form the cement-soil by using the single-shaft, double-shaft or three-shaft stirring pile machine; and then inserting one (or a plurality of) core material (such as the prestressed concrete tubular pile, the prestressed concrete square pile, the precast reinforced concrete member and the like) into the cement-soil by a vibration or self-weight method to obtain the composite pile body. The composite pile has higher bending strength, tensile strength and shear strength so as to meet different bearing requirements, and has the lateral bearing capacity 30 percent higher than that of the core pile and comprehensive cost 40 percent lower than that of a bored pile.

Description

A kind of cement-soil composite pile that inserts reinforced concrete core

One, technical field

The present invention relates in the geotechnical engineering weak rock-reinforcing and support technology, form the combination pile body, will improve its reinforcing and support capacity greatly, and can effectively reduce construction costs by insert high-strength piling at the cement-soil stirring body.

Two, technical background

In the engineering construction in China area such as coastal, riverine, ubiquity foundation soil weakness, poor stability, the characteristics that bearing capacity is on the low side, especially comparatively fast regional in economic development, be used for ground and handle and the employed expense of bracing of foundation pit, will have more than hundred billion yuan every year.At present, in China's ground processing and bracing of foundation pit engineering, the technology that adopts mainly contains: vibration or static pressure pile-sinking, bored pile, compaction pile, cement mixing method or high-pressure rotary jet grouting pile etc., often there are many defectives in these construction technologies and are subjected to engineering geology and the construction environment restriction, be difficult to penetrate when running into powder soil horizon or flour sand layer as static pressed pile, it is limited that deep-mixed pile is handled the degree of depth, static pressed pile requires too high to the operation site condition, vibrator sunk pile has noise pollution, bored pile produces mud emission and pollutes, compaction pile then has the moving defective such as disturb residents of shake (shaking).Deep-mixed pile body itself usually only uses as water-stop curtain because intensity is lower, and can not singlely use as bearing peg, often like this causes difficulty for design and construction, and construction cost is significantly improved.

In view of above-mentioned stake type uses the difficulty of construction of existence and the deficiency of intensity respectively, through experimental study for many years, we have invented a kind of new ground and have handled and reinforcing technique---the cement-soil composite pile of reinforced concrete core, this type has not only overcome all deficiencies of stake type commonly used at present, and is a kind of not only environmental protection but also economic new stake type.

Three, summary of the invention

The cement-soil composite pile of reinforced concrete core is an insertion prestressed concrete pipe pile in stirring cement earth pile (stirred forms by single shaft, two or three mixing pile machines) deeply, or prestressed concrete square pile, or reinforced concrete member, or a kind of NEW TYPE OF COMPOSITE stake of forming as core such as reinforcing bar tube stake, it is made up of the very high core stake two parts of cement mixing method and intensity, as shown in Figure 1.

Use single shaft, two or three mixing pile machines, at first the soil body and cement grout mix are formed cement-soil, insert the pile body that (or several) core (prestressed concrete pipe pile, the stake of prestressed concrete pipe side, precast reinforced concrete structure etc.) is composited by vibration then.The composite pile of Xing Chenging has higher bending resistance, tension and shear strength like this, can satisfy different load bearing requirements.By effective combination of deep layer stirring concrete earth pile and core stake, the composite pile of formation, its bearing capacity improves 30% than core pile capacity, and comprehensive cost reduces more than 40%.

Concrete characteristics are as follows:

(1) bearing capacity height: by inserting effective combination of core stake in the cement mixing method, the flexural strength and the vertical bearing capacity that have increased stake greatly improve greatly;

(2) construction costs is low: with compare with other type of bearing capacity, construction costs reduces more than 40%;

(3) suitable stratum is extensive: mud, silt clay, clay, silt, flour sand layer etc.;

(4) reinforcing soft ground: can be used as the enhancing body of composite foundation, mud, mucky soil etc. is carried out ground stabilization;

(5) curtain water stop supporting: can make the curtain water stop soldier pile, overcome stir deeply can only sealing can not supporting deficiency;

(6) be used for uplift pile: the deep layer stirring concrete earth improves the side friction of precast reinforced concrete pile greatly, thereby compound pile body uplift resistance is significantly improved, and can be used as uplift pile;

(7) economic environmental protection: noise is little, pollution-free, economic environmental protection

Four, description of drawings (body matter)

A kind of form of structure of inserting the cement-soil composite pile of reinforced concrete core of Fig. 1

The 1-deep layer soil body that mixes cement; 2-reinforced concrete core (left side is that prestressed reinforced concrete pipe pile, the right side are the stake of prestressed reinforced concrete side); The tension side of 3-composite pile; 4-presstressed reinforcing steel body; The 5-ground surface.

Five, the specific embodiment

(1), at first use single shaft, two or three mixing pile machines, the soil body and cement grout mix are formed cement-soil

(2), then by vibration or insert the pile body that (or several) core (prestressed concrete pipe pile, the stake of prestressed concrete pipe side, precast reinforced concrete structure etc.) is composited.

(3), the insertion position with the flexural strength of composite pile is required relevant, when requiring to have higher flexural strength, then the core of Cha Ruing should close be subjected to the crook; When requiring to have higher vertical bearing capacity, then the core of Cha Ruing should overlap with the center of agitation pile.

Claims

1. a cement-soil composite pile that inserts reinforced concrete core is combined by cement earth pile parcel reinforced concrete core.

2. composite pile structure according to claim 1 is characterized in that its cement earth pile is stirred by single shaft, two or three mixing pile machine deep layers to form.

3. composite pile structure according to claim 1, the reinforced concrete core that it is characterized in that inserting in the cement earth pile is a prestressed concrete pipe pile, or prestressed concrete square pile, or reinforced concrete member, or the steel concrete barrel mast, or reinforcing cage.

4. composite pile structure according to claim 1 is characterized in that adopting vibration or inserts reinforced concrete core from weighing method.