Construction method of dock diaphragm wall under complex working conditions

Abstract

The invention discloses a construction method of a dock diaphragm wall under complex working conditions, which comprises the following steps: 1) cutting and stirring a soil body by a canal type cutting machine in a vertical direction and then in a transverse moving manner to form an equal-thickness underground diaphragm wall structure used as the dock diaphragm wall; and (2) the section steel is driven downwards along the center line of the wall body of the dock diaphragm wall at uniform intervals. And (3) top beams which are horizontally arranged and connected with the profile steel pile heads are poured. And (4) a jack is adopted for tensioning the anchor beams to apply prestress, so that the crown beam, the profile steel and the anchor rods are fixedly connected into a whole, and a piled anchor type supporting system of the dock diaphragm wall is formed. 5.1) constructing a dock anchorage wall and other structural facilities; or 5.2) removing the top beam and the anchor rod, respectively pulling out the profile steel in the cement soil, and grouting and filling the cement soil hole after the profile steel is pulled out through the grouting pipe, so as to build the dock diaphragm wall. The construction period of the dock diaphragm wall is shortened, the construction efficiency is improved, and the construction cost is remarkably reduced.

Description

Technical Field

[0001] The invention belongs to the technical field of dock construction, and in particular relates to a construction method of a dock anti-seepage wall with anti-seepage and supporting functions under complex geological conditions. Background Art

[0002] In the construction of new docks and the renovation and expansion of old docks, the construction of anti-seepage walls is particularly important. At present, hydraulic grab trenching machines are generally used to dig and pour plain concrete to form underground continuous walls as anti-seepage walls. Figure 1 As shown, from top to bottom, there are the first silt layer 101, the muddy soil layer 102, the second silt layer 103, the silt layer 104 and the third silt layer 105. The geological conditions are poor, the groundwater level is high and the water permeability is strong. In addition, the existing dock needs to be released and drained many times during the construction process, and the groundwater level in the construction area fluctuates greatly. On the other hand, during the dock extension and reconstruction construction, steel sheet piles need to be used in the anti-seepage wall area for multiple support excavations in stages, and structural facilities such as the construction dock empty box pile foundation and the anchor behind the wall are used. The entire construction process has many procedures, complex construction technology and frequent changes in construction conditions, and the entire construction organization needs to be effectively planned and deduced.

[0003] In the dock construction and expansion projects, the anti-seepage wall is generally constructed in the form of an underground continuous wall. The traditional anti-seepage wall construction technology is very likely to cause problems such as trench wall collapse and joint leakage under this condition. It is necessary to take effective measures such as trench wall reinforcement and precipitation to meet the construction conditions and ensure the quality of the anti-seepage wall construction. The construction period is long and the construction cost is high.

[0004] At the same time, a large amount of waste soil and mud will be generated during the construction of the underground continuous wall. In the later stage, it is necessary to break the guide walls on both sides of the slot excavated by the hydraulic grab slotting machine, which play a guiding and wall protection role. The construction period is long, the construction investment is large, and the construction quality and safety risks are high. In addition, there are other structures in the construction area of ​​the dock anti-seepage wall that need to be supported and excavated. The fact that the support and anti-seepage functions cannot be taken into account at the same time has further increased the construction investment and delayed the construction period. Summary of the invention

[0005] The purpose of the present invention is to provide a dock anti-seepage wall construction method for complex working conditions, which can be used as a dock anti-seepage wall structure and also can be used as foundation pit excavation support, thereby effectively solving the problems existing in the traditional dock anti-seepage wall construction method.

[0006] The present invention is achieved through the following technical solutions:

[0007] A method for constructing a dock anti-seepage wall under complex working conditions comprises the following steps:

[0008] Step 1) firstly measure and lay out the construction scope of the dock anti-seepage wall on the concrete ground, then use a channel cutter to vertically cut the mixed soil to the bottom elevation of the anti-seepage wall, and then drive the cutter to move horizontally to cut the mixed soil to construct an underground continuous wall of equal thickness used as the dock anti-seepage wall;

[0009] Step 2) Before the cement soil of the dock anti-seepage wall initially sets, steel sections are driven downward at even intervals along the center line of the dock anti-seepage wall;

[0010] Step 3) After the dock anti-seepage wall reaches the designed strength, the slope is excavated to the bottom elevation of the crown beam, the residual soil on the steel pile heads is cleaned, and the steel bars are tied at the steel pile heads and then the crown beams that are horizontally arranged and connected to the steel pile heads are cast, and the cross sections of the crown beams close to the steel pile heads are respectively reserved with beam penetration inclined holes;

[0011] Step 4) After the crown beam reaches the design strength, the anchor bundle is obliquely passed through the bundle oblique hole, and cement slurry is injected into the bundle oblique holes reserved in the crown beam by a high-pressure rotary jet pile machine to form anchor rods; finally, the anchor bundles are tensioned by a jack to apply prestress, so that the crown beam, each steel and each anchor rod are fixedly connected into one, forming a pile-anchor support system for the dock anti-seepage wall;

[0012] The following steps are carried out according to two working conditions:

[0013] Working condition 1: Step 5.1) After the pile-anchor support system is built, excavate earth to the construction bottom elevation of the dock anchor wall, and construct the dock anchor wall and other structural facilities;

[0014] Working condition 2: Step 5.2) After completing the construction of the pile-anchor support system, remove the cap beam and each anchor rod, use a jack to pull out the steel sections in the cement soil, and set grouting pipes in the cement soil holes after the steel sections are pulled out. Fill the cement soil holes with grouting through the grouting pipes to build a dock anti-seepage wall, and backfill gravel on the bottom plate of the dock anchor wall to the ground.

[0015] The purpose of the present invention can be further achieved by the following technical measures.

[0016] Furthermore, the steel section is an H-shaped steel section.

[0017] Furthermore, the ratio of the height H to the width B of the cross section of the crown beam is: H / B=0.55-0.65.

[0018] Furthermore, the angle between the inclined anchor bundle and the horizontal plane is α=25° to 35°.

[0019] Furthermore, the pre-tension load value of the anchor bundle tensioning is 100 kN, the standard tension load value is 421 kN, and the test tension load value is 545 kN.

[0020] The present invention uses cement soil underground continuous wall as dock anti-seepage wall, and does not need to carry out guide wall construction and other reinforcement and precipitation measures on the groove wall. Through the transverse excavation, mixing and horizontal advancement construction of the channel cutter, a high-quality cement soil underground continuous wall with no joints and equal thickness is built. During the construction process, a large amount of abandoned soil and mud will not be generated. A small amount of cement soil floating slurry can be stored in a pre-set foundation groove, and can be used as temporary road materials on the site after treatment, which significantly reduces the pollution of construction waste. By inserting steel sections arranged at intervals in the cement soil and pouring a horizontal crown beam on the top thereof, the pile-anchor support system composed of multiple rows of steel sections, anchor rods and the crown beam on the top can also be used as structural facilities such as anchors behind the dock wall, which plays a supporting role for excavation, and no additional support measures such as steel sheet piles are required. After the construction is completed, the steel sections in the soil can also be pulled out and recycled, which reduces the construction investment and also saves the area occupied by the support structure. The present invention shortens the construction period of the dock anti-seepage wall, improves the construction efficiency, and significantly reduces the construction cost.

[0021] Advantages and features of the present invention will be illustrated and explained by the following non-limiting description of preferred embodiments thereof, which are given by way of example only with reference to the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] Figure 1 is a cross-sectional view of working condition 1 of the present invention;

[0023] Figure 2 is a cross-sectional view of working condition 2 of the present invention;

[0024] Figure 3 yes Figure 1 A-axis enlarged view. DETAILED DESCRIPTION

[0025] The present invention will be further described below in conjunction with the accompanying drawings and an embodiment of the construction of a dock anti-seepage wall in the dock reconstruction project of Jinling Shipyard. Figure 1 and Figure 2 The upper left corner in the figure is the dock chamber 100 which is undergoing reconstruction.

[0026] like Figure 1 to Figure 3 As shown, a method for constructing a dock cut-off wall under complex working conditions comprises the following steps:

[0027] Step 1) First, measure and lay out the construction range of the dock anti-seepage wall 10 on the ground, then use a channel cutting machine to vertically cut the mixed soil to the bottom elevation of the anti-seepage wall, and then the channel cutting machine drives the tool to move horizontally to cut the mixed soil to construct an underground continuous wall of equal thickness used as the dock anti-seepage wall 10.

[0028] Step 2) Before the cement soil of the dock cut-off wall 10 begins to set, the steel sections 1 are driven downwards at even intervals along the center line of the dock cut-off wall 10 .

[0029] Step 3) After the dock anti-seepage wall 10 reaches the designed strength, the slope is cut to the bottom elevation of the crown beam 2, and the residual soil on the pile heads of the steel sections 1 is cleaned respectively. After the steel bars are tied at the pile heads of the steel sections 1, the crown beam 2 which is horizontally arranged and connects the pile heads of each steel section 1 is cast, and the cross section of the crown beam 2 close to the pile head of the steel section 1 is reserved with inclined holes 21 for passing the beams.

[0030] Step 4) After the crown beam reaches the design strength, the anchor bundle 31 is obliquely passed through the bundle oblique hole 21, and a high-pressure rotary jet pile machine is used to inject cement slurry into the bundle oblique holes 21 reserved in the crown beam 2 to form anchor rods 3. Finally, the anchor bundles 31 are tensioned by jacks to apply prestress, so that the crown beam 2, each steel 1 and each anchor rod 3 are fixedly connected as a whole, forming a pile anchor support system for the dock anti-seepage wall. The tension preload value is 100kN, the standard tension load value is 421kN, and the detection tension load value is 545kN.

[0031] The following steps are carried out according to two working conditions:

[0032] Working condition 1: If Figure 1 As shown, in step 5.1), after the pile-anchor support system is built, earth is excavated to the construction bottom elevation of the dock anchor wall 20, and the dock anchor wall 20 and other structural facilities are constructed.

[0033] Working condition 2: If Figure 2 As shown, in step 5.2), after the construction of the pile-anchor support system is completed, the cap beam 2 and the anchor rods 3 are removed, and the steel sections 1 in the cement soil are respectively pulled out using a jack, and grouting pipes are respectively set in the cement soil holes 11 after the steel sections 1 are pulled out, and the cement soil holes 11 are filled with grouting through the grouting pipes, thereby building a dock anti-seepage wall 10, and backfilling gravel 4 on the dock anchor wall bottom plate 201 to the ground.

[0034] The steel 1 of this embodiment is an H-shaped steel, and the specification of the H-shaped steel is 400×400×13×21. The ratio of the height H to the width B of the cross section of the crown beam 2 is: H / B=0.60. The angle α between the inclined anchor bundle 31 and the horizontal plane is 30°.

[0035] In addition to the above embodiments, the present invention may also have other implementation modes. Any technical solutions formed by equivalent replacement or equivalent transformation shall fall within the protection scope required by the present invention.

Claims

1. A method for constructing a dock anti-seepage wall under complex working conditions, characterized in that: The following steps are involved: Step 1) First, measure and lay out the construction scope of the dock anti-seepage wall on the ground, then use a channel cutter to vertically cut the mixed soil to the bottom elevation of the anti-seepage wall, and then drive the cutter to move horizontally to cut the mixed soil to construct an underground continuous wall of equal thickness used as the dock anti-seepage wall; Step 2) Before the cement soil of the dock anti-seepage wall initially sets, steel sections are driven downward at even intervals along the center line of the dock anti-seepage wall; Step 3) After the dock anti-seepage wall reaches the designed strength, the slope is excavated to the bottom elevation of the crown beam, the residual soil on the steel pile heads is cleaned, and the steel bars are tied at the steel pile heads and then the crown beams that are horizontally arranged and connected to the steel pile heads are cast, and the cross sections of the crown beams close to the steel pile heads are respectively reserved with beam penetration inclined holes; Step 4) After the crown beam reaches the design strength, the anchor bundle is obliquely passed through the bundle oblique hole, and cement slurry is injected into the bundle oblique holes reserved in the crown beam by a high-pressure rotary jet pile machine to form anchor rods; finally, the anchor bundles are tensioned by a jack to apply prestress, so that the crown beam, each steel and each anchor rod are fixedly connected into one, forming a pile-anchor support system for the dock anti-seepage wall; The following steps are carried out according to two working conditions: Working condition 1: Step 5.1) After the pile-anchor support system is built, excavate earth to the construction bottom elevation of the dock anchor wall, and construct the dock anchor wall and other structural facilities; Working condition 2: Step 5.2) After completing the construction of the pile-anchor support system, remove the cap beam and each anchor rod, use a jack to pull out the steel sections in the cement soil, and set grouting pipes in the cement soil holes after the steel sections are pulled out. Fill the cement soil holes with grouting through the grouting pipes to build a dock anti-seepage wall, and backfill gravel on the bottom plate of the dock anchor wall to the ground.

2. The method for constructing a dock cut-off wall under complex working conditions as claimed in claim 1, characterized in that: The steel section is an H-shaped steel section.

3. The method for constructing a dock cut-off wall under complex working conditions as claimed in claim 1, characterized in that: The ratio of the height H to the width B of the crown beam cross section is: H / B=0.55~0.

65.

4. The method for constructing a dock cut-off wall under complex working conditions as claimed in claim 1, characterized in that: The included angle α between the inclined anchor bundle and the horizontal plane is 25° to 35°.

5. The method for constructing a dock cut-off wall under complex working conditions as claimed in claim 1, characterized in that: The pre-tension load value of the anchor bundle tensioning is 100kN, the standard tension load value is 421kN, and the test tension load value is 545kN.

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