Summary of personal work of steel structure engineer

I joined Sinochem Sanjian Company in July, 1993, and have been engaged in riveting. I have a strong sense of responsibility, due diligence, service obedience and a high level of professional knowledge. During the 17 years' working time, I have participated in large and medium-sized domestic and foreign projects, such as the renovation of Anqing Refinery, Jiujiang Big Fertilizer, Dalian Western Pacific Refinery, Gansu Qingyang Refinery, Shashi Tianfa Grease Factory, Shaanxi Huaxian Fertilizer, Hefei Sifang Group's "8.13" Project, Hebei Qinhuangdao Fertilizer Factory, Hainan Big Fertilizer, Yinchuan Jiemei Fertilizer, Shenhua Coal-to-Liquid, Huizhou Refinery, Qinghai Golmud Methanol Project, and Vietnam Ningping Fertilizer Factory's new ammonia plant construction project. Through so many years' work, I have learned the professional knowledge, theory and experience of riveters. Now I have participated in the assembly of the roof structure of the converter and the production and installation of chimneys in the project.

A summary of the installation work of the roof structure of the reforming furnace (taking the methanol steam reforming furnace in Qinghai as a model) The construction sequence of the roof splicing

1. Laying of the platform by steel structure assembly: the roof is 19.438m in length and 5.4m in width after assembly and splicing. There are ***5 pieces of' roof with axes A, B, C, D and E that need to be spliced and assembled on the ground. In order to reduce the waiting time of hoisting station, a 2m*1m steel structure assembly platform was laid on the ground.

2. The sequence of roof splicing and assembling: the roof splicing and assembling of axis A-E are the same. Take the roof of axis A as an example: firstly, the bottom beams 13G4 and 13G14 of the roof are spliced and put in place, and the distance between the bottom beams and the top beams is subject to the supporting height in the middle; Then, the two side supports 136VB24 of the bottom beam and the top beam are combined, and then the middle supports 136VB31 and 136VB32 are combined to finalize the overall shape of the roof. Finally, the support between the top beam and the bottom beam of the roof is spliced and installed in turn. After the roof integral splicing group is completed, the roof is hoisted in place by crane, and the supports 136VB4, bottom beams 13G4 and 13G14, top beams WL18 and WL19 are connected and fixed with the structural columns in turn. In this order, the roofs of other axes are spliced and installed in place.

3. Roof hoisting (Take the hoisting of the roof of Axis A as an example, the same applies to others). The installation height of the roof is 3.75m, the center height of the roof top is 36.165m, the roof top beam specification is H44*3*11*18, and the roof top height is 36.385m.. When hoisting, the height of the crane hook head from the roof top beam shall not be less than 2m, and the distance between the crane hook head and the top of the crane boom shall not be less than 2m. According to the minimum height, the vertical hoisting height of the selected crane shall not be less than 4m. The height of the structural columns (3C1, 3C6) used to install the roof is 33.75m, and the distance between the two columns (3C1, 3C6) is 2m, that is, the distance between the crane lifting hook head and the columns on either side is 1m.

the assembled weight of the whole roof of axis A is 11.448t, and the assembled weight of other roof groups is 11.962t. Take the maximum weight of 12t as the calculation base and multiply it by the safety factor of 1.2, that is, the calculated lifting weight should be 14.4t.

due to the influence of the inner pipe gallery in the north of the converter furnace and other equipment foundations when hoisting the roof, the hoisting crane needs to stand in the south of the furnace structure. In order to avoid the crane shifting and wasting time. The hoisting crane shall be positioned on the center line of axis C. According to the road conditions on the ground north of the furnace body, the turning radius of the crane is 26 -28 meters. Calculated by the farthest radius of gyration of 28 meters, the length of the crane from the center of the roof of axes A and E is 3.46 meters, that is, the radius of gyration of the roof of axes A and E hoisted by the crane is 3.46 meters. Calculated by 31 meters, that is,

the radius of gyration of the crane is 31 meters, the hoisting weight is 14.4t, and the vertical hoisting height is at least 4 meters. It is calculated that the length of the main boom of the crane is at least 51m. Therefore, according to Shanghai Tengfa crane mining, the hoisting crane should be at least 25 tons truck crane. The specific hoisting scheme is compiled by the engineering technician, and only the preliminary selection and consideration of hoisting are made here.

4. Assemble the steel structure into pieces

Assemble the steel structure into pieces in the field prefabrication yard according to the hoisting capacity, equipment installation sequence, and the weight, rigidity and deflection of the steel frame after being sliced. Before slicing, the columns should be on the same horizontal plane, and the error should not be greater than 5 mm. After slicing, the diagonal, column axis, parallelism and beam levelness should meet the specification requirements. At the same time, the bottom of the column should be ensured to be on the same plane, and the column beam should not be distorted.

5. Temporary support measures for roof structure:

In order to ensure the stability of post installation, 244*175*7*11 H-beam is used to connect the post with the roof support after post installation to form a stable space.

As the beams between the columns B, C and D of Axis 1 have not arrived, it is necessary to consider increasing the temporary fixation between these three columns. Construction method: firstly, install the 1-D axis column in place, and then connect and fix the column with the roof support; Install the 1-E axis column in place and connect and fix it with the 1-D axis column. After completion, install the 1-C axis column in place, and connect and fix the 1-C axis column with the 1-D axis and the roof support respectively. Install and fix the remaining columns in this order.

according to the distance between axes, the amount of temporary fixed supporting materials used is:

(553mm+553mm+563mm+563mm+563mm+563mm+563mm+5756mm+651. The use of this material is mainly to create benefits. As a result, it has been recognized by the owners and achieved remarkable benefits.

B, summary of steel structure fabrication and installation work

1. First, it is necessary to determine the layout of temporary facilities on site to prepare for construction work:

A, a steel platform with length * width = 12m * 6m should be erected on the site during chimney fabrication, and the inner and outer pipe joints of the chimney should be made on the platform. When assembling, wooden piles should be erected on site, and the stack placement position should be the same as that before hoisting.

B, the roads on the site should be smooth, the site should be smooth, and there should be no sundries that hinder the construction.

C, the crib supporting the chimney barrel should be placed stably. In order to facilitate welding and hoisting, the height of the crib should not be less than 1m.

D, the cylinder can't be placed directly on the crib, but should be supported by saddle bearings to prevent the cylinder from being deformed due to local compression.

2. acceptance of foundation: before chimney installation, the foundation shall be accepted, and the axis and elevation of foundation, the relative position of anchor bolts, etc. shall be checked according to the data, and whether backfilling and tamping around the foundation are completed. The allowable deviation of the bearing surface and anchor bolt shall meet the following requirements:

allowable deviation of the project (mm)

bearing surface elevation 5.

levelness l/1

anchor bolt center deviation 2.

bolt exposure length ,2

3. When girth weld is assembled, crane and jack can be used to adjust the cylinder concentricity. The gap between circumferential seams is adjusted by 8 groups of flower basket bolts evenly distributed along the cylinder.

4. Blanking, coiling and assembling the cylinder

a. Drawing the cylinder typesetting diagram according to the arrival size of the steel plate.