CN-122013835-A - Groove wall reinforcement and combined groove construction method for ultra-deep underground diaphragm wall

CN122013835ACN 122013835 ACN122013835 ACN 122013835ACN-122013835-A

Abstract

The invention discloses a groove wall reinforcement and combined groove construction method of an ultra-deep underground continuous wall, which aims at the problem that the perpendicularity of a traditional triaxial stirrer is difficult to control in deep groove wall reinforcement and the section of a reinforcement body is irregular, adopts double-wheel stirring equipment to reinforce the groove wall, and realizes real-time monitoring and adjustment of the perpendicularity by a self-contained inclinometer so as to improve the overall stability of the groove wall. In order to achieve the combination of grooving precision and construction efficiency, a 'grabbing and milling combined' segmented grooving process for cooperative operation of a grooving machine and a grooving machine is provided, wherein the grooving machine is adopted for construction in a range of 4m below a guide wall, the grooving machine is adopted for construction in a range of 4m below the guide wall to 2m below a substrate, the characteristics of small cutting footage and low disturbance are utilized, the main control verticality is realized by combining visual monitoring, and the grooving machine is restored for construction in a range of 2m below the substrate to a designed groove bottom area so as to improve the grooving efficiency. The method effectively solves the problems of difficult control of the perpendicularity of the ultra-deep underground continuous wall and unstable grooving quality, and realizes double optimization of construction quality and efficiency.

Inventors

You Shaoqiang
ZENG BIAO
SONG HUAN
ZHANG DINGWEN
Mu Yuechao
ZHOU JIE
LIU YONGCHAO
Qu Tianhang

Assignees

中铁十四局集团有限公司
中铁十四局集团大盾构工程有限公司
东南大学

Dates

Publication Date: 20260512
Application Date: 20260115

Claims (9)

1. A groove wall reinforcing and combined groove construction method for ultra-deep underground continuous walls is characterized by comprising the following steps: s1, site treatment and guide wall construction, namely, site three-way leveling is performed, groundwater is simulated by using software, precipitation is implemented, and an L-shaped guide wall is constructed; S2, reinforcing the wall of the double-wheel stirring tank, namely reinforcing soil bodies on two sides of the wall of the tank to 2m below a substrate by using double-wheel stirring equipment to form a high-precision reinforced waterproof curtain, wherein the verticality is controlled within 1/300; S3, combined grooving excavation, namely dividing the underground continuous wall grooving section into three operation sections in the depth direction according to the soil layer characteristics and the reinforcement range, and carrying out relay excavation in a mode of combining a grooving machine with a grooving machine; s4, cleaning the tank, changing slurry and brushing the wall, namely cleaning the tank by adopting a gas lift reverse circulation method, controlling the thickness of sediment at the tank bottom to be less than 10cm, and brushing the wall for at least 20 times on the side wall joint; s5, hoisting the reinforcement cage and pouring concrete, namely, placing the reinforcement cage into a groove in a segmented or integral manner, and pouring underwater concrete by using a conduit method.
2. The method for reinforcing and combining the walls of the ultra-deep underground diaphragm wall into the groove according to claim 1, wherein the step S1 is characterized in that the software is used for simulating the underground water and the precipitation step is implemented before the construction: A, establishing a three-dimensional seepage numerical model by utilizing Visual ModFlow software, and performing simulation operation according to the seepage coefficient in a geological survey report; And B, arranging dewatering wells according to simulation results, and controlling the groundwater level around the tank section to a specific depth below the ground so as to ensure the stability of the tank wall in the tank forming process.
3. The method for reinforcing and combining the groove walls of the ultra-deep underground diaphragm wall into the groove according to claim 1, wherein the double-wheel stirring groove wall reinforcing construction in the step S2 adopts a positioning control and lap joint process, and specifically comprises the following steps: setting control lines in the direction of parallel grooves, and performing coarse positioning by utilizing double hanging hammers below an operation platform to align with the control lines; B, displaying the inclination of the drill rod in real time by utilizing an inclinometer arranged on the double-wheel stirring equipment, and controlling the verticality deviation within 1/300; and C, implementing engagement lap joint between adjacent stirring piles, setting the lap joint width to be 200mm, and enabling the next gear edge to invade the upper pile body by adjusting the position of a lifting hammer so as to ensure the continuity of the waterproof curtain.
4. The method for reinforcing and constructing the composite trench wall of the ultra-deep underground diaphragm wall according to claim 1, wherein the concrete operation flow of the composite trench excavation construction in the step S3 is as follows: A, a first section, namely excavating by using a grooving machine from the top surface of a guide wall to a depth range of 4m below the guide wall; Cutting and excavating from 4m below the guide wall to 2m below the foundation pit base by using a slot milling machine, wherein the slot milling machine is used for actively controlling and rectifying verticality in a second interval with small disturbance to soil and reverse circulation slag discharge characteristics; And C, in the third section, from 2m below the foundation pit base to the bottom of the design groove of the underground continuous wall, the excavation is resumed by using a grooving machine, and the construction efficiency of the deep soil layer is improved by utilizing the characteristic of large single excavation amount.
5. The method for reinforcing and combining the groove walls of the ultra-deep underground diaphragm wall into the groove according to claim 1, wherein the ultrasonic detection technology is adopted for quality tracing in the groove forming construction process in the step S3: the method comprises the steps of A, carrying out perpendicularity and aperture scanning on the excavated groove wall by utilizing an ultrasonic detector, generating a digital record, and realizing traceability of construction quality of each grab and each mill; and B, measuring the depth of the groove section by combining with a measuring hammer, and evaluating the quality grade of the groove section.
6. The method for reinforcing and combining the groove walls of the ultra-deep underground diaphragm wall into the groove is characterized in that a reverse circulation deslagging process is adopted in the construction stage of a groove milling machine in the step S3, slurry indexes are controlled as follows, hopper viscosity is 25-30S, relative density is 1.03-1.10, pH value is 8-9, and when the groove milling machine cuts soil, the cut soil residues are discharged through a reverse circulation system, so that lateral extrusion disturbance on the soil body in a reinforced area is reduced.
7. The method for reinforcing and combining the groove walls of the ultra-deep underground diaphragm wall into the groove according to claim 1, wherein the underground diaphragm wall is constructed by adopting a stage jump digging method: dividing the tank section into a phase I tank section and a phase II tank section, constructing the phase I tank section firstly, and constructing the phase II tank section at an intermediate interval after the concrete reaches the design strength; And B, for the L-shaped or Z-shaped corner groove section, when the length of the groove section is smaller than the opening size of the grab bucket of the groove forming machine, a method of lengthening the guide wall is adopted, so that the length of the working surface meets the mechanical operation requirement.
8. The method for reinforcing and combining the groove walls of the ultra-deep underground diaphragm wall into the groove according to claim 1, wherein the qualified standard of the groove cleaning and slurry changing in the step S4 is that the specific gravity of slurry in the height of 200mm of the groove bottom is not more than 1.3 and the thickness of sediment at the groove bottom is not more than 100mm after the bottom cleaning and slurry changing for 1 hour.
9. The method for reinforcing and combining the groove walls of the ultra-deep underground diaphragm wall into the groove according to claim 1, wherein in the step S5, a double-machine lifting process is adopted for an overweight steel reinforcement cage with the weight exceeding 500t, lifting is completed through the steps of lifting horizontally, lifting obliquely, returning in the air, unbuckling an auxiliary lifting machine and putting the main lifting machine into the groove, and a plurality of lifting ribs, longitudinal truss reinforcing ribs and 7-shaped ribs are arranged on the steel reinforcement cage to ensure the lifting rigidity.

Description

Groove wall reinforcement and combined groove construction method for ultra-deep underground diaphragm wall Technical Field The invention belongs to the technical field of underground foundation engineering construction, and relates to a groove wall reinforcement and combined groove construction method for an ultra-deep underground continuous wall, in particular to a groove wall reinforcement construction method for an ultra-deep underground continuous wall by utilizing double-wheel stirring (CSM) under complex geological conditions of rich water, deep soft soil and the like, and adopting a groove forming machine (hydraulic grab) and a groove milling machine (double-wheel milling) to be combined in a segmented mode. Background Along with the development and utilization of urban underground space, the depth of the underground continuous wall serving as a deep foundation pit support structure is continuously increased, and the construction environment is increasingly complex (such as adjacent rivers, water-rich sand layers, deep soft soil and the like). In ultra-deep underground diaphragm wall construction, the stability of the groove wall and the perpendicularity of the groove are key factors for determining success and failure of engineering. In the prior art, the reinforcement of the wall of the underground diaphragm wall is generally constructed by adopting a triaxial stirrer. However, the section of the triaxial mixer pile is in a sawtooth triangle shape, the lap joint between piles is easy to form false joint or weak point, and the mechanical rigidity of the triaxial mixer itself limits the verticality control capability along with the increase of the reinforcing depth, so that the reinforcing body is easy to incline inwards or skim outwards, and the grooving precision and the water stopping effect of the subsequent continuous wall are affected. In terms of the grooving process, conventional construction methods generally use either a grooving machine (rope grab or hydraulic grab) or a milling machine singly. The grooving machine has high excavation efficiency, large single excavation amount, poor precision control, difficult excavation of hard stratum, large disturbance on the piston effect of the groove wall, high grooving precision of the grooving machine, small disturbance on the soil body, capability of cutting hard rock, extremely high equipment operation cost, small single scale feeding amount and relatively low construction efficiency. In the face of underground continuous walls with ultra-deep (such as more than 60 m) and ultra-wide (such as 1.2m-1.5 m) and complex geological conditions, the requirement of perpendicularity quality control and construction period progress is often difficult to be met by a single grooving mode. Therefore, a new construction method is needed, which can effectively solve the problem of controlling the reinforced perpendicularity of the deep groove wall, and can combine the advantages of different grooving equipment to realize high-quality and high-efficiency construction of the ultra-deep underground continuous wall. Disclosure of Invention In order to solve the problems, the invention discloses a groove wall reinforcing and combined groove forming construction method for an ultra-deep underground continuous wall, which realizes double improvement of construction quality and efficiency by optimizing a groove wall reinforcing process and constructing a combined groove mode of grabbing, milling and grabbing. In order to achieve the above purpose, the technical scheme of the invention is as follows: a groove wall reinforcing and combined groove forming construction method for ultra-deep underground continuous wall comprises the following steps: s1, site treatment and guide wall construction, namely, site three-way leveling is performed, groundwater is simulated by using software, precipitation is implemented, and an L-shaped guide wall is constructed; S2, reinforcing the wall of the double-wheel stirring tank, namely reinforcing soil bodies on two sides of the wall of the tank to 2m below a substrate by using double-wheel stirring equipment to form a high-precision reinforced waterproof curtain, wherein the verticality is controlled within 1/300; S3, combined grooving excavation, namely dividing the underground continuous wall grooving section into three operation sections in the depth direction according to the soil layer characteristics and the reinforcement range, and carrying out relay excavation in a mode of combining a grooving machine with a grooving machine; s4, cleaning the tank, changing slurry and brushing the wall, namely cleaning the tank by adopting a gas lift reverse circulation method, controlling the thickness of sediment at the tank bottom to be less than 10cm, and brushing the wall for at least 20 times on the side wall joint; s5, hoisting the reinforcement cage and pouring concrete, namely, placing the reinforcement cage into a groove in a segmente