CN201284475Y

CN201284475Y - Combined concrete cut-off wall

Info

Publication number: CN201284475Y
Application number: CNU2008200417876U
Authority: CN
Inventors: 张启富; 程观富; 陈景富; 王天星; 冯立孝
Original assignee: ANHUI SURVEY AND DESIGN INSTITUTE OF WATER CONSERVANCY AND HYDROPOWER
Current assignee: ANHUI SURVEY AND DESIGN INSTITUTE OF WATER CONSERVANCY AND HYDROPOWER
Priority date: 2008-09-03
Filing date: 2008-09-03
Publication date: 2009-08-05
Anticipated expiration: 2018-09-03

Abstract

The utility model relates to the technical field of water resource sustainable use and water-saving agriculture and a combined type concrete cut-off wall in the water project, and solves the problem that a composite ground layer has obviously unreasonableness of adopting the homogenous material concrete cut-off wall. The combined type concrete cut-off wall comprises an upper wall body, a lower wall body and a middle transition section; wherein, the upper wall body is made of plastic concrete, and the lower wall body is made of cement concrete, and the middle transition section is made of semi-plastic concrete. The beneficial effects are as follows: 1) corresponding impermeable material is adopted in consideration of the water head pressure born by the wall body so as to satisfy the requirements for impervious safety and reduce construction cost; 2) the upper wall body adopts the plastic concrete to improve the stress state of the whole cut-off wall; 3) the adhesive property between the plastic concrete and a cohesive soil layer is good, which is favorable for ensuring the integrity and the wholeness of a dam body; and 4) the lower wall body adopts the cement concrete, thus having high strength and good impermeability; and the lower wall body can be combined with the bedrock at the lower part of highly permeable sand and gravel layer well, so the anti-erosion property of the contact surface of the lower wall body and the bedrock is enhanced.

Description

The combined type concrete cut

Technical field

The technical field that the utility model relates to is the concrete cut in sustainable utilization of water resource and water-saving agricultural technology and the hydraulic engineering.

Background technology

In water resource and hydraulic engineering, often adopt concrete cut to carry out underground soil layer antiseepage, to take in the ground construction grooving, slurry strengthened wall keeps slotted eye stable, and mud downcomer placing of concrete forms impervious wall.The material that impervious wall adopts there is no unified regulation, generally adopts rigid concrete more, and the wet concrete of employing or semi plastic concrete are also arranged.Generally, all adopt the impervious wall of homogenous material, promptly no matter how soil layer property reaches the head height, or adopt rigid concrete, or adopt wet concrete or semi plastic concrete.(bottom is highly permeable sand or sandy gravel stratum but for compound stratum, top is weak permeable viscous soil horizon), adopt the concrete cut of homogenous material to have tangible irrationality: the impermeability and the intensity of wet concrete are lower, are not suitable for being applied in the sandy gravel stratum of bottom; Rigid concrete is too firm, fractures easily or ftractures in the viscous soil horizon of top.

Rigid concrete: refer generally to elastic modulus E 〉=10000MPa, compressive strength R ₂₈The concrete of 〉=10MPa; Wet concrete: refer generally to elastic modulus E≤2000MPa, compressive strength R ₂₈The concrete of≤5MPa; Semi plastic concrete: modulus of elasticity and the compressive strength concrete between said two devices.

Summary of the invention

In order to solve the problem that concrete cut that compound stratum (bottom is highly permeable sand or sandy gravel stratum, and top is weak permeable viscous soil horizon) adopts homogenous material has obvious irrationality, the utility model provides a kind of combined type concrete cut.

Concrete technical solution is as follows:

The combined type concrete cut comprises top body of wall, bottom body of wall and middle transition section,

Described top body of wall is a wet concrete, and the bottom body of wall is a rigid concrete, and the middle transition section is the semi plastic concrete.

Described wet concrete top body of wall design objective is: compressive strength R ₂₈=3-5MPa, elastic modulus E=1000-2000MPa, osmotic coefficient k=10 ^-6-10 ^-7Cm/s;

Described rigid concrete bottom body of wall design objective is: compressive strength R ₂₈〉=10MPa, elastic modulus E 〉=10000MPa, osmotic coefficient k=10 ^-8-10 ^-9Cm/s;

Semi plastic concrete middle transition section design objective is: compressive strength R ₂₈=5-15MPa, elastic modulus E=2000-10000MPa, osmotic coefficient k=10 ^-7-10 ^-8Cm/s;

Described lower walls height degree L ₁: L ₁=embedding rock depth d+sand gravel layer thickness+stretch into length s in the soil body of top,

Described middle transition section height L ₂: L ₂=4-7 rice,

Described top body of wall height L ₃: L ₃=body of wall overall height L-rigid concrete height L ₁-changeover portion height L ₂

Described embedding rock depth d: fresh rock is not less than 0.5m, or decayed rock is not less than 1.0m.

Described rigid concrete stretches into length s in the soil body of top: general s=H/6-8, wherein H is that water levels of upstream and downstream is poor.

The useful technique effect of combined type concrete cut is embodied in several aspects: the 1. head size of bearing according to body of wall, adopt corresponding impervious material, and satisfy the antiseepage safety requirements, reduce construction costs.2. wet concrete is adopted on top, increases it and adapts to deformation ability, reduces the constraint to bottom rigid concrete body of wall, reduces the additional vertical stress of body of wall that settlement of stratum produces, and improves the stress state of whole impervious wall.3. the adhesive property between wet concrete and the viscous soil horizon is good, in conjunction with tight.Be used for seepage control of dam, little to the cleavage fracture effect of dam body or dam earth core, help guaranteeing the integrality and the globality of dam body.4. the bottom body of wall bears higher head and bigger stress.Rigid concrete intensity height, anti-permeability performance is good; The basement rock of itself and highly permeable sandy gravel stratum bottom is combined, and strengthens itself and basement rock contact surface erosion resistibility.

Description of drawings

Fig. 1 is the utility model structural representation.

Sequence number explanation among the figure: 1-wet concrete, 2-rigid concrete, 3-changeover portion, 4-cohesive soil dam body, 5-sand gravel pervious layer, 6-dam foundation face, 7-bedrock surface, 8-basement rock, 9-reservoir normal pool level, 10-dam crest, 11-dam level of tail water.

The specific embodiment

Below in conjunction with accompanying drawing, the utility model is further described by embodiment.

Compound stratum is common in water resource and hydraulic engineering, because of the geology characteristic of stratum, riverbed deposition, the bottom is generally coarse granule highly permeable sandy gravel stratum, and top is generally the weak permeable viscous soil horizon of fine grained, on the deep covering layer riverbed, build retaining works, often run into this stratum.In old reservoir reinforcement or newly-built earth dam engineering, the dam bottom is a sand gravel highly permeable layer, is that the example of soil property dam body or earth core is a lot of on it.For compound stratum, the utility model patent is suitable for.

Embodiment:

Referring to Fig. 1, the combined type concrete cut comprises top body of wall 1, bottom body of wall 2 and middle transition section 3.Top body of wall 1 is a wet concrete, and bottom body of wall 2 is a rigid concrete, and middle transition section 3 is the semi plastic concrete.

Combined type concrete cut thickness T: H is relevant with the water levels of upstream and downstream difference, general T=H/ (60-80).

Embed the rock depth d: relevant with water levels of upstream and downstream difference H and rock property, general fresh rock is not less than 0.5m, and decayed rock is not less than 1.0m.

Rigid concrete stretches into length s in the soil body of top: relevant with the character of the water levels of upstream and downstream difference H and the top soil body, and general s=H/ (6-8).

Rigid concrete height L ₁: L ₁=embedding rock depth d+sand gravel layer thickness+stretch into length s in the soil body of top.

Changeover portion height L ₂: relevant with job practices with the wet concrete height, general L ₂=4-7m.

Wet concrete height L ₃; L ₃=body of wall overall height L-rigid concrete height L ₁-changeover portion height L ₂

Operating principle

Top body of wall 1 and the common antiseepage of weak permeable viscous soil horizon, the head that body of wall is born is lower; Upper soil horizon distortion is relatively large, dam concrete impervious wall especially, and top dam deformation amount is big; For strengthening the deformability of top body of wall, wet concrete is adopted on top, and cementitious material cement, clay, swell soil by a certain percentage determines that by Mix Ratio Test the body of wall design objective is: compressive strength R ₂₈=3-5MPa, elastic modulus E=1000-2000MPa, osmotic coefficient k=10 ^-6-10 ^-7Cm/s.Body of wall is almost born whole water-heads of upstream and downstream in the highly permeable sandy gravel stratum of bottom, should improve the impervious durability of body of wall; Under the upper load effect, soil layer produces depression, will make body of wall produce additional pressure at right angle, and body of wall 2 gravity pressures in bottom are also bigger, thereby need to improve the compressive strength of bottom body of wall.Rigid concrete is adopted in the bottom, and cementitious material is a cement, mixes an amount of flyash and Admixture, is determined by Mix Ratio Test.The body of wall design objective is: compressive strength R ₂₈〉=10MPa, elastic modulus E 〉=10000MPa, osmotic coefficient k=10 ^-8-10 ^-9Cm/s.Between wet concrete and the rigid concrete semi plastic concrete transition region, general compressive strength R ₂₈=5-15MPa, elastic modulus E=2000-10000MPa, osmotic coefficient k=10 ^-7-10 ^-8Cm/s.

Job practices

At first carry out the concrete mix test, determine the materials for wall prescription by the body of wall design objective; Design axis segmentation grooving (general every section flute length 6-8m) along impervious wall at the scene, slurry strengthened wall, downcomer is to bottom land; Earlier mix the system concrete by the match ratio of rigid concrete, by the catheter irrigation concrete to the above 2-5m of design height (deciding) on the impervious wall degree of depth; Changing pouring wet concrete to wall again pushes up.Wherein, because the length of embedment of conduit and the whereabouts inertia of placing of concrete form semi plastic concrete transition region naturally between wet concrete and rigid concrete.

Concrete mix:

Rigid concrete match ratio (every cubic metre of material usage kg): water 235-245, cement 330-370, flyash 120-130, Admixture 9-11, sand 720-740, stone 920-940.

Wet concrete match ratio: (every cubic metre of material usage kg): water 335-345, cement 240-280, swell soil 70-80, clay 130-140, Admixture 9-11, sand 590-610, stone 700-720.

Changeover portion concrete mix: between rigid concrete and wet concrete.

Claims

1, combined type concrete cut is characterized in that: comprise top body of wall, bottom body of wall and middle transition section,

2, combined type concrete cut according to claim 1 is characterized in that:

Described middle transition section height L ₂: L ₂=4-7 rice,

3, combined type concrete cut according to claim 2 is characterized in that: described embedding rock depth d: fresh rock is not less than 0.5m, or decayed rock is not less than 1.0m.

4, combined type concrete cut according to claim 2 is characterized in that: described rigid concrete stretches into length s in the soil body of top: general s=H/6-8, wherein H is that water levels of upstream and downstream is poor.