New method for designing and constructing 35m high pole lamp

Abstract: The foundation of high pole lights above 30 meters is often designed and applied according to the pile foundation. The method is safe and reliable, but the cost is high, in the economy. Reasonable, safe and durable principle, this paper combines national norms and construction practices, points out the key links and precautions in the basic design, and combines examples to propose an optimized, economical and safe high pole lamp basic design.

Keyword: 35m high pole light base sturdy and stable

In the construction of the project, the port has a large area of grain yards, ore yards, container yards due to night lighting needs, according to The size of the area, the average yard is equipped with mast lights. The mast lamp is generally a stereotyped product produced by a professional manufacturer, and is installed and commissioned by the manufacturer. The foundation construction drawing provided by the manufacturer is based on the pile foundation. Inspired by the experience of using various types of freight yards in the region, whether or not the pile foundation can be used, and the bottom of the foundation can be dug deep, and then the machine is compacted. On this basis,

the load factor table 2

Serial    Loading load  Wind number                 Description

2       1.0            1.0         Calculating wind pressure 0.25 KN/m2

3        0            1.2         Calculate wind pressure 0.8~1.2KN/m2

Concrete pouring, we have made detailed calculations to ensure its safety, the effect after the actual construction can prove that this method is safe, economical and reasonable.

1. Analysis of the load on the lamp base The load on the basis of the lamp is not only the weight of the lamp body, but also some other loads. According to the type of action, the load can be divided into three categories:

1.1 Basic load, including the weight of the lamp body, the weight of the lamp, and the weight of the cable;

1.2 Additional load, including wind load under normal conditions (regardless of area, uniform sampling. 25KN/m2) ;

1.3 Special loads, including special conditions, such as wind loads in storm conditions (20 m from the ground, 0.80 KN/m2, more than 20 m above the ground, 1.10 KN/ M2. Calculate the load combination and combine as follows

When calculating, the loads should be multiplied by the corresponding load factor according to the specification. It is obvious that these load factors are obvious. It is completely different from the current sub-unit load coefficient adopted by the civil engineering according to the limit state theory.

According to the current national standard

Basic vertical force     ;     1.2

The overturning moment and torque of the base 1.4

Span style="white-space:pre">         1.4

2. Analysis of geology < pan="">

Geological survey of the site before excavation of the foundation pit, according to the qualitative survey report:

2.3 The part of the corners on both sides of the end slope Calculation: VE = DW/3

If the slope coefficient m is different from the formula: VE = DW/3, special attention should be paid to the selection of Du, and Du is the thickness of the mud layer at the bottom end of the end slope (see figure two).

3. Calculation of the amount of earthwork and stonework

Principle: The segmentation range of the trench should be the same as the design time; the amount of earthwork for completion should be calculated as follows:

VI = A(H1 -H2)   Vf the amount of earthwork for the trench (m3);

A the actual formation of the slope and the slope of the end slope Area within the deepening range (m2);

H1 the average water depth (m) during completion of the actual deepening of the trench;

H2 the actual deepening range of the trench The average water depth (m) before starting work.

The above is only a brief description of some of the problems encountered by individuals in calculating the amount of dredging using the average water depth method and the cited standards. It should be noted that the average water depth method is a mechanization of dredging earth and stone. The work with relatively large workload and very error-prone work, in addition to strictly following the standards carefully and carefully, in the calculation process, different people should be accounted for by different calculation methods, only when calculating the amount and accounting. The amount of measurement is within the specified error range before the calculation result can be finalized. It is gratifying that some departments have developed and used the software to conduct dredging and earthwork electronic calculations. The calculation workload is small and the error is small. However, there is no corresponding specification to regulate these, so the meter is used. When calculating the amount of earth and stone, be sure to use the software approved by the relevant department.

2.1 It is believed that the site is stable and suitable for construction.

2.2 The standard depth of the survey site is 0.8 m.

2.3 The survey site is a weak site soil, and the type of exploration site is m class

The structural strength of the cable-filled land in the survey site is enhanced by 150 kpa. p>

3. Construction process 3.1 Foundation pit excavation

After positioning the specific position of the mast light, the foundation pit is excavated. The diameter of the pit is 10 meters, the depth is 4.8 meters, and the depth is 4.8. m, the specific size is shown below

3.2 Backfilling large blocks of stone

After the foundation pit is dug, backfill with large stones and backfill the thickness of 2 meters. Be careful, be sure to lay it apart, and a large piece of stone is placed in the middle to ensure that the big stone is under the pressure of the foundation.

3.3 Using the boring machine, the diameter of the bottom surface of the tamper hammer used in this project is 1.5 meters. The sniper method adopts the principle of first center and the last four weeks. The cockroach can control above 300KNm and stop. The standard is: the final settlement of acetonitrile is less than 2 mm. If there is a rubber-soil phenomenon in the sniper process, measures should be taken according to the actual situation to ensure the quality of the project. The 2 m stone backfilled in the middle of the project, in which 50 cm of sedimentation is reserved, such as the sinking amount is more than 50 cm. Should be added a block. Make sure the concrete foundation is 20 cm above the ground.

3.4Concrete pouring, backfilling gravel compaction

Concrete concrete on the basis of compacted block stones, place pre-welded steel cages, and reserve pipes for reserved cables. The mold is poured, the mold is removed after curing, and the surrounding is filled with medium fine gravel, and compacted by a vibratory roller. The foundation construction is completed.

4. Conclusion

Mast under construction with this method under the favorable conditions of downtime The light base can be compared with the pile foundation provided by the original manufacturer, but the economic cost of this method is 50% less than the pile foundation.