A method for treating soft soil reconsolidation under dynamic load

Abstract

The present application relates to a kind of soft soil reconsolidation under dynamic load processing method, solve the vibration drainage of existing soft soil in consolidation method vibration frame structure, it is difficult to manufacture vibration support foundation, construction is inconvenient, the problem of destruction of foundation after recovery.The method mixes cement in upper layer soil, forms cement soil base layer with strength in C5-C15;Uniformly set water pipe on cement soil base layer;Vibration rod is set in each water pipe;Place stack load plate on cement soil base layer, and vibration machine is fixed on stack load plate;Vibration machine fixed on stack load plate vibrates, drives vibration rod in water pipe, and free water generated after vibration is collected in water pipe, water in water pipe is discharged using water suction pump, until no free water is discharged after a period of vibration operation.The present application solves the problem that general vibration machine cannot effectively vibrate deep layer soil, and removes free water generated after vibration from soil, simultaneously, promotes soil particle to rearrange, and enhances soil compactness.

Description

Technical Field

[0001] This invention relates to an engineering construction technique, and more particularly to a method for treating the reconsolidation of soft soil under dynamic loads. Background Technology

[0002] With the advancement of society and technology, people's demand for transportation is increasing daily. Therefore, various modes of transportation have developed rapidly in recent years. In engineering practice, traffic loads are ubiquitous, and the quasi-static method is generally used in design to apply these loads to the roadbed. Traffic loads and other dynamic loads generate vibrations, which produce waves. These waves transfer energy, and elastic waves propagate outwards, causing soil settlement. The foundations beneath highways, seawalls, and subways generally experience stable settlement during the static load period, but significant subsequent settlement may occur during operation. For saturated soft soil treatment, methods such as consolidation without drainage and static load-bearing plastic drainage boards are commonly used. However, even after these methods, significant settlement may still occur in the roadbed after completion and operation.

[0003] Currently, there are also methods that use dynamic load vibration to break down the impermeable layer for drainage, such as Chinese patent CN102409662A published on April 11, 2012, entitled "Method for Drainage Consolidation Treatment of Soft Soil Foundation." This method involves vertically connecting a hollow pipe to the middle of a rigid frame, with suction holes at the bottom of the hollow pipe. Multiple sets of keel plates are evenly distributed in the middle of the rigid frame. A permeable membrane is used to wrap the rigid frame, hollow pipe, and keel plates. The structure is then driven into the foundation. A vacuum pump is installed in the hollow pipe. The outer periphery of the permeable membrane is blocked by fine particles, forming an impermeable layer. The vibrator is then activated, and the keel plates distribute the vibration force to the periphery of the rigid frame. The fine particles on the outer periphery of the permeable membrane are broken by the vibration, and the drainage pipe continues to drain water until the foundation is consolidated. Another method uses a hollow pipe installed inside a frame structure. A vibrator drives the frame to vibrate, thereby breaking down the impermeable layer and allowing the hollow pipe to drain water. This method involves a large frame structure, making it difficult to drive into the foundation and subsequently recover. Furthermore, to facilitate frame installation and recovery, an effective supporting foundation cannot be created on the ground surface; the vibrator must be supported by the frame itself, limiting its power and preventing multiple frames from using the same vibrator, resulting in high construction costs. Also, due to the large frame structure, recovery leaves significant pits in the foundation soil, damaging the foundation and causing hollow areas. If not addressed promptly and effectively, this can pose safety hazards. Summary of the Invention

[0004] The purpose of this invention is to solve the problems of existing vibration drainage methods for consolidating soft soil, such as large vibration frame structures, difficulty in manufacturing vibration support foundations, inconvenient construction, and damage to the foundation after recycling. The invention provides a method for reconsolidating soft soil under dynamic loads, which uses a combination of a vibrator and a vibrating rod inserted into the soil and a seepage pipe to drain the free water generated by the vibration of deep soil.

[0005] The technical solution adopted by this invention to solve its technical problem is: a method for reconsolidating soft soil under dynamic load, comprising the following steps:

[0006] Step 1: Mix the top layer of soil with cement to form a cement-soil base layer with a strength of C5-C15.

[0007] Step 2: Evenly install drainage pipes on the cement-soil base layer;

[0008] Step 3: Install a vibrator inside each seepage pipe to form a vibrator-seepage pipe combination. The burial depth of the lower end of the vibrator is greater than the burial depth of the lower end of the seepage pipe.

[0009] Step 4: Place a slab on the cement-soil base and fix the vibrator on the slab;

[0010] Step 5: The vibrator fixed to the slab vibrates, driving the vibrator in the seepage pipe to collect the free water generated after vibration in the seepage pipe. The water in the seepage pipe is discharged by a water pump until no free water is discharged after the vibration has been running for a period of time.

[0011] Step 6: Remove the vibrator, and retrieve the slab, vibrator, and seepage pipe in sequence. Install steel pipes to protect the original seepage holes and grout them to ensure they are compacted.

[0012] In this application, step 1 can directly form a cement-soil base course on the soil to be treated, providing a rigid working layer for the vibratory machine and a larger vibration bearing area, thus aiding subsequent drainage. Step 4 involves laying a slab on top of the cement-soil base course and placing the vibratory machine on it to prevent the machine from sinking and damaging the cement-soil base course. This also facilitates vibration transmission, allowing one vibratory machine to drive multiple vibratory rods within its range. The vibratory rod and permeable pipe combination inserted into the soil solves the problem of ineffective vibration of deep soil layers by conventional vibratory machines, drains free water generated after vibration, and promotes soil particle rearrangement, increasing soil density. This scheme uses a small-diameter permeable pipe inserted into the roadbed, followed by the vibratory rod. This reduces material and construction costs. After consolidation, when recycling the vibratory rod and permeable pipe, only a small hole the size of the permeable pipe remains, facilitating reinforcement and grouting without causing secondary damage to the roadbed.

[0013] Preferably, in step 1, the thickness of the soil layer above the cement mixture is not less than 30cm.

[0014] As a preferred option, in step 2, the density of the seepage pipes is one per 1-25 square meters, with a depth of more than 2 meters.

[0015] Preferably, in step 3, the outer diameter of the vibrator is smaller than the inner diameter of the seepage pipe, and a drainage gap is left between the vibrator and the seepage pipe.

[0016] Preferably, in step 3, the vibration frequency of the vibrator is 83~133HZ, 5000~8000 times / min.

[0017] Preferably, in step 3, the depth of the vibrator buried is more than twice the depth of the seepage pipe.

[0018] Preferably, in step 4, the surcharge plate is made of steel plate or a special waterproof composite road plate.

[0019] Preferably, in step 4, the vibration frequency of the vibrator is 40-60 Hz.

[0020] Preferably, the vibratory roller is a vibratory roller.

[0021] This invention, a combination of a vibratory rod and a drainage pipe, solves the problem that general vibratory machines cannot effectively vibrate deep soil, and drains the free water generated after vibration out of the soil. At the same time, it promotes the rearrangement of soil particles and enhances soil density. During construction, a cement-soil base layer is constructed first to provide a rigid working layer for the vibratory machine, making vibration transmission more efficient. The construction materials are low-cost and will not cause secondary damage to the roadbed. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of one structure of the present invention.

[0023] In the diagram: 1. Cement-soil base course, 2. Loading plate, 3. Vibrator, 4. Drainage pipe, 5. Vibrator rod. Detailed Implementation

[0024] The present invention will be further described below with reference to specific embodiments and accompanying drawings.

[0025] Example: A method for treating soft soil reconsolidation under dynamic load, such as... Figure 1 As shown, it includes the following steps:

[0026] Step 1: Mix the top layer of soil with cement to form a cement-soil base layer with a strength of C5-C15; the thickness of the top layer of soil mixed with cement should not be less than 30cm.

[0027] Step 2: Evenly install drainage pipes on the cement-soil base; the drainage pipe density is one per 1-25 square meters, and the depth is more than 2 meters;

[0028] Step 3: Install a vibrator inside each seepage pipe to form a vibrator-seepage pipe combination. The burial depth of the lower end of the vibrator is greater than that of the lower end of the seepage pipe, and the burial depth of the vibrator is more than twice that of the seepage pipe. The outer diameter of the vibrator is smaller than the inner diameter of the seepage pipe, and a drainage gap is left between the vibrator and the seepage pipe. The vibration frequency of the vibrator is 83~133HZ, 5000~8000 times / min.

[0029] Step 4: Place a slab on the cement-soil base course. The slab is made of a special permeable composite roadbed plate. Fix a vibratory roller on the slab.

[0030] Step 5: The vibrator fixed to the slab vibrates at a frequency of 40-60 Hz, driving the vibrator in the seepage pipe to collect the free water generated after vibration in the seepage pipe. The water in the seepage pipe is discharged by a water pump until no free water is discharged after the vibration has been running for a period of time.

[0031] Step 6: Remove the vibrator, and retrieve the slab, vibrator, and seepage pipe in sequence. Install steel pipes to protect the original seepage holes and grout them to ensure they are compacted.

Claims

1. A method for reconsolidating soft soil under dynamic load, characterized in that: Includes the following steps: Step 1: Mix the top layer of soil with cement to form a cement-soil base layer with a strength of C5-C15. Step 2: Evenly install drainage pipes on the cement-soil base layer; Step 3: Install a vibrator in each seepage pipe to form a vibrator-seepage pipe combination. The burial depth of the lower end of the vibrator is greater than the burial depth of the lower end of the seepage pipe. The outer diameter of the vibrator is smaller than the inner diameter of the seepage pipe. A drainage gap is left between the vibrator and the seepage pipe. Step 4: Place a slab on the cement-soil base and fix the vibrator on the slab; Step 5: The vibrator fixed to the slab vibrates, driving the vibrator in the seepage pipe to collect the free water generated after vibration in the seepage pipe. The water in the seepage pipe is discharged by a water pump until no free water is discharged after the vibration has been running for a period of time. Step 6: Remove the vibrator, and retrieve the slab, vibrator, and seepage pipe in sequence. Install steel pipes to protect the original seepage holes and grout them to ensure they are compacted.

2. The method for reconsolidating soft soil under dynamic load according to claim 1, characterized in that: In step 1, the thickness of the soil layer above the cement mixture should be no less than 30cm.

3. A method for reconsolidating soft soil under dynamic load according to claim 1 or 2, characterized in that: In step 2, the density of the seepage pipes is one per 1-25 square meters, with a depth of more than 2 meters.

4. The method for reconsolidating soft soil under dynamic load according to claim 1, characterized in that: In step 3, the vibration frequency of the vibrator is 83~133HZ, 5000~8000 times / min.

5. A method for reconsolidating soft soil under dynamic load as described in claim 1 or 4, characterized in that: In step 3, the vibrator is buried at a depth more than twice the depth of the seepage pipe.

6. The method for reconsolidating soft soil under dynamic load according to claim 1, characterized in that: In step 4, the surcharge plate is made of steel plate or a special waterproof composite road plate.

7. The method for treating soft soil reconsolidation under dynamic load according to claim 1, characterized in that: In step 4, the vibration frequency of the vibrator is 40-60 Hz.

8. A method for reconsolidating soft soil under dynamic load according to claim 1, 6, or 7, characterized in that: The vibratory roller is a vibratory road roller.

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