Lanzhou Ecological Cultural and Creative City Country Garden Park Pile Foundation Construction Project

Time:2020year5month

Project: Country Garden, Lanzhou Ecological Cultural and Creative CityPile foundation construction in the park

Geology:0-30mFor plain filling,28-50mFor the Malan loess,50mThe following is argillaceous sandstone

Pile Diameter:Φ0.8m； Pile Depth:55-63m, the bearing layer is argillaceous sandstone, into the rock5-10m

Construction technology: long casing construction

Device configuration:SR285RW10Match φ508-4×17mMachine lock lever + φ900mmBarrel + φ800mmThe body is open and the sand bucket is used

1, project overview

Country GardenThe park is located next to the main road of Lanzhou Ecological Cultural and Creative City, with four meetings and five reaches, and is close to prosperity. The total area of the project is about148acres, with a total construction area of about27.7410,000 square meters, planning22buildings. The construction of pile foundation requires the pile diameter of bored piles800mm, pile depth35-65mAccording to the engineering and geological conditions, the construction unit finally chooses SanySR285RW10Carry out full casing construction.

2、SR285RW10Model features:

SR285RW10It is positioned in the construction of long casing, full stroke and large aperture rock formations, and has the following advantages:

Full casing construction: the length of the casing can be reached in a single lower casing17m, Lifting force355kN, the first in the same model in the industry;

Full stroke pressurization: a single pressurized stroke can be reached17m, no need for multiple pressurization;

Rapid pressurization: The pressurized winch is quickly lifted up and down, and the speed can be reached21m/min, which is the normal pressurization speed3Fold;

Automatic centralized lubrication: all lubrication points are automatically lubricated, and the service life of key parts is improved50%。

3, construction method

Country GardenThe geology of the park uptown is0-30mplain fill,28-50mMalan loess,50mThe following strongly weathered argillaceous sandstone, with large water content, is prone to engineering accidents such as hole collapse, necking, and full drilling in the drilling process, thereby delaying the construction period and affecting the progress of the project, and the construction of the full casing needs to be adopted.

The construction method of the long casing of the rotary drilling rig is mainly driven by the power head key sleeve to drive the drill pipe and drilling tools to circulate the soil, and the lower end of the power head sleeve drives the casing driver and the casing and other supporting facilities to carry out the casing operation, and the two cooperate to complete the hole forming construction process of the rotary drilling rig. The construction method can pass through the unstable layer for the specific stratum of the project, reduce the difficulty of mud matching, so as to achieve the purpose of increasing the stability of construction and reducing the construction period.

For the most difficult in this project40For the construction of the long casing above the meter, the construction unit selects Sany after comparisonSR285RW10。 In order to reduce the frictional resistance and drilling resistance in the construction process of the casing, the method of drilling and following the pipe is adopted: drilling by the rotary drilling host9-11mThe hole is deep, and the first section of the casing is adopted5m+6mThe sheath section is connected altogether11mThe whole is lowered into the hole to increase the length of the first and lower parts of the casing and improve the construction efficiency of the casing. Subsequently, each cycle operation has been drilled down with a body bucket or a sand bucket4-5mAfter completion5mThe casing follows downward until it is long enough to pass through the unstable layer. It is worth pointing out that the depth of each drill is determined by the specific stratum in the construction method of drilling first and pipe, and the depth of drilling should be minimized when the stratum is more loose and easy to collapse.

After the casing is lowered, the body bucket or sand bucket is drilled to the depth of the required hole, and the sediment at the bottom of the hole is removed by the hole cleaning bucket to meet the requirements of the pile foundation sediment thickness requirements, and the whole process of rotary digging into the hole construction is completed.

4, case summary

Country GardenPark Uptown construction site altogether3The rotary drilling rig is constructed, which is SanySR285RW10, TrinitySR220and other manufacturers280。12#The floor pile is deep22The largest in the building, the average depth of the casing40m, among them12-18The depth of the stake casing is even more reached47m, bySR285RW10Self-extrication, not dependent on any auxiliary equipment,10hourly hole-making,13Hour into pile, creating the longest length of the self-pulling casing of equipment of the same level in China. At the same site, a domestic manufacturer of the same type of rotary drilling rig casing from the bottom limit32rice33The meter cannot be pulled out independently, and the casing can be pulled out from the bottomSR285RW10Far more than other manufacturers.

According to the statistics,SR285RW10It can be completed every day1.5-2root pile, the efficiency is other manufacturers2Fold. Efficient on-site management is complemented by a strong SanySR285RW10In addition to labor, fuel consumption, equipment loss and auxiliary equipment leasing costs, it can create profits for customers in a single day210,000 yuan On-site management: Mr. Zhang: YesSR285RW10The construction performance of the full casing was full of praise: "Trinity285The rotary drilling drill has good performance and the machine is stable, and Country Garden's project depends on it."