CN-121110733-B - Construction method of existing underground structure anti-floating reinforcement grouting composite anchor rod system

CN121110733BCN 121110733 BCN121110733 BCN 121110733BCN-121110733-B

Abstract

The invention discloses a construction method of an existing underground structure anti-floating reinforcement grouting composite anchor rod system, which comprises a plugging and leakage-stopping sleeve arranged in a bottom plate, an anchor rod bone pipe arranged in the plugging and leakage-stopping sleeve and extending into soil, cement paste and a main stress rib arranged in the anchor rod bone pipe, and an anchor head locking assembly arranged at the top of the anchor rod bone pipe and used for fixing the main stress rib; the invention can carry out positioning protection and joint overall waterproof on the anchor rod bone pipe at the bottom plate by the joint arrangement of the plugging leakage-stopping sleeve and the bottom sealing concrete layer in construction, is beneficial to forming a more reliable stressed main body in the anchor rod bone pipe by the arrangement of the main stressed rib, is connected with the bottom plate by the arrangement of the anchor head locking component, is beneficial to integral stress, is beneficial to construction in a short and small underground space, has small disturbance and is beneficial to ensuring grouting quality by the static pressure equipment and the sectional construction.

Inventors

CAO GUANGXU
HUA PENGLIN
YANG SHENGGUI
YAO ZHIQUAN
LI YANG
LIU LIYAN
Hao Rencheng
LIU DE
JIAO BO
ZHAO QI

Assignees

建研地基基础工程有限责任公司

Dates

Publication Date: 20260512
Application Date: 20251029

Claims (9)

1. The construction method of the existing underground structure anti-floating reinforcement grouting composite anchor rod system is characterized in that the existing underground structure anti-floating reinforcement grouting composite anchor rod system comprises a plugging and leakage-stopping sleeve arranged in a bottom plate, an anchor rod bone pipe arranged in the plugging and leakage-stopping sleeve and extending into soil, cement paste and main stress bars arranged in the anchor rod bone pipe, and an anchor head locking assembly arranged at the top of the anchor rod bone pipe and used for fixing the main stress bars; the construction method for the existing anti-floating reinforcement grouting composite anchor rod system of the underground structure comprises the following specific steps: Determining the position of a drilled hole according to a design drawing, wherein when diving or pressure-bearing water is arranged below the bottom plate and the underground water head line is higher than the top elevation of the bottom plate, the drilled hole on the bottom plate is not drilled thoroughly temporarily, and a bottom sealing concrete layer of 5 cm-10 cm is reserved at the bottom of the drilled hole, so that the underground water can not leak in; the method comprises the steps of arranging a plugging leakage-stopping sleeve in an opening of the bottom plate, wherein the outer diameter of the plugging leakage-stopping sleeve is the same as the aperture of the opening of the bottom plate, and the inner diameter of the plugging leakage-stopping sleeve is arranged corresponding to the outer diameter of a bone pipe of an anchor rod; the plugging leakage-stopping sleeve is an extrusion deformation sleeve, and the sleeve is manufactured by a rubber pipe or a plastic pipe; Installing static pressure equipment on the bottom plate, pressing the anchor rod bone pipe into the stratum in sections through the plugging and leakage-stopping sleeve, and adopting sealing measures to connect the sections, wherein the depth of pressing into the soil layer meets the design requirement of the anchor rod; grouting by using a sectional grouting device, and adding cement paste into the anchor rod bone tube after grouting of the outer side of the anchor rod bone tube is completed; And fifthly, after the grouting body strength of the anchor rod and the bone pipe meets the requirement, tensioning the main stressed bar through the anchor head locking assembly and locking the main stressed bar on the top surface of the bottom plate, thereby completing the construction of the existing anti-floating reinforcement grouting composite anchor rod system of the underground structure.
2. The construction method of the existing underground structure anti-floating reinforcement grouting composite anchor rod system according to claim 1, wherein the bore hole on the bottom plate is 100 mm-350 mm in diameter.
3. The construction method of the existing underground structure anti-floating reinforcement grouting composite anchor rod system according to claim 1, wherein the anchor rod bone tube comprises an anchor rod, an anchor rod hole arranged on the outer wall of the anchor rod and an anchor rod head arranged at the bottom end part of the anchor rod, the anchor rod head is in a closed conical pointed shape, and the hardness corresponds to breaking of the arranged concrete layer and pressing of soil.
4. The construction method of the existing underground structure anti-floating reinforcement grouting composite anchor rod system according to claim 3, wherein the anchor rod is tubular and spliced, anchor rod holes are correspondingly formed in each segmented anchor rod during construction, one-way grouting valves are installed in the anchor rod holes, splicing parts are connected through threads or sleeves, and sealing connection is carried out at the butt joint parts through sealing rings or sealing glue.
5. The construction method of the existing underground structure anti-floating reinforcement grouting composite anchor rod system according to claim 4, wherein the cement slurry has a water cement ratio of 0.4-0.7, and the grouting is performed under pressure during the construction of the cement slurry, so that the slurry in the anchor rod is kept full and spread around.
6. The construction method of the existing underground structure anti-floating reinforcement grouting composite anchor rod system according to claim 1, wherein the anchor head locking assembly comprises an anchor plate, an anchor base plate arranged below the anchor plate and an anchor head arranged at the top of the anchor plate, the anchor plate is a circular plate, a through hole is arranged on the circular plate and penetrates through a main stress rib, the anchor base plate is a circular plate with the diameter larger than the outer diameter of a bone pipe of an anchor rod, and the anchor head is an extrusion anchor or a clamping piece anchor.
7. The construction method of the existing underground structure anti-floating reinforcement grouting composite anchor rod system according to claim 1, wherein the static pressure equipment is door type static pressure equipment or holding pressure type static pressure equipment, the height of the static pressure equipment is lower than the height of a basement, and the bottom of the static pressure equipment is fixedly connected with a bottom plate through foundation bolts.
8. The construction method of the existing underground structure anti-floating reinforcement grouting composite anchor rod system according to claim 1, wherein in the fifth step, the main stress tendons are steel strands, common steel bars, finish rolling threaded steel or fiber reinforced composite materials, and the main stress tendons are respectively arranged corresponding to working conditions of applying tensioning prestress or not applying prestress.
9. The method for constructing an existing underground structure anti-floating reinforcement grouting composite anchor rod system according to claim 1, wherein in the fifth step, when a thickened bottom plate is newly added above the bottom plate, an anchor head locking assembly is arranged inside the newly poured bottom plate.

Description

Construction method of existing underground structure anti-floating reinforcement grouting composite anchor rod system Technical Field The invention relates to the technical field of anti-floating reinforcement of existing buildings, in particular to a construction method of an anti-floating reinforcement grouting composite anchor rod system of an existing underground structure. Background Along with the acceleration of the urban updating process, a great amount of underground space of the existing building needs to be transformed and utilized. Meanwhile, the ground of many existing buildings has obvious rising of the groundwater level due to the implementation of ecological water supplementing and groundwater limited recovery. The original underground structure is not fully considered to resist floating or the design water level of the floating resistance is low during construction, so that under the action of the buoyancy of the rising underground water, the huge risks of floating of the structure, cracking of the bottom plate and even overall instability occur. The traditional anti-floating reinforcement method has the problems of large construction amount, environmental influence, persistent effect, policy restriction and the like such as increasing the weight (earth covering or counterweight), lowering the groundwater level and the like. Another common method is to arrange an anti-floating anchor rod, but when the conventional anti-floating anchor rod construction method is applied to the reinforcement of the existing underground structure, the technical or environmental problems are faced that the construction space is limited, the working surface is usually positioned in a built room, the space is narrow, and large equipment is difficult to spread. When the groundwater level is higher than the bottom plate, in order to guarantee the construction, need a long time large tracts of land precipitation, and the precipitation can influence surrounding environment, arouses the peripheral ground easily and subsides, the underground pipeline warp, building slope etc. secondary disasters and precipitation cycle are very long, and the precipitation degree of difficulty is big, and precipitation expense is high. In addition, the drilling machine or hammering technology adopted in the construction of the common anchor rod can cause secondary damage to the original structure due to vibration and pressure generated in the construction process, and the anchoring reliability is low. Therefore, there is an urgent need for an anti-floating reinforcement construction method for an existing underground structure, which is highly targeted, efficient in construction, capable of avoiding construction precipitation, environment-friendly, pollution-free and reliable in anchoring. Disclosure of Invention The invention provides a construction method of an existing underground structure anti-floating reinforcement grouting composite anchor rod system, which is used for solving the technical problems that the existing anti-floating anchor rod is limited in space, difficult to construct in groundwater environment, low in connection reliability and the like during construction. In order to achieve the above purpose, the invention adopts the following technical scheme: the existing underground structure anti-floating reinforcement grouting composite anchor rod system comprises a plugging and leakage-stopping sleeve arranged in a bottom plate, an anchor rod bone pipe arranged in the plugging and leakage-stopping sleeve and extending into soil, cement paste and a main stress rib arranged in the anchor rod bone pipe, and an anchor head locking assembly arranged at the top of the anchor rod bone pipe and used for fixing the main stress rib; the construction method for the existing anti-floating reinforcement grouting composite anchor rod system of the underground structure comprises the following specific steps: Determining the position of a drilled hole according to a design drawing, wherein when diving or pressure-bearing water is arranged below the bottom plate and the underground water head line is higher than the top elevation of the bottom plate, the drilled hole on the bottom plate is not drilled thoroughly temporarily, and a bottom sealing concrete layer of 5 cm-10 cm is reserved at the bottom of the drilled hole, so that the underground water can not leak in; Step two, placing a plugging leakage-stopping sleeve in the opening of the bottom plate, wherein the outer diameter of the plugging leakage-stopping sleeve is the same as the aperture of the opening of the bottom plate, and the inner diameter of the plugging leakage-stopping sleeve is arranged corresponding to the outer diameter of the bone tube of the anchor rod; Installing static pressure equipment on the bottom plate, pressing the anchor rod bone pipe into the stratum in sections through the plugging and leakage-stopping sleeve, and adopting sealing measures to connect