Concentrate and despatch to the plateau

Not long ago, in the Changsha second industrial park of China Railway Construction Heavy Industry Co., Ltd., the railway tunnel construction equipment of China Railway Construction Heavy Industry Co., Ltd. on the plateau was assembled and shipped, aiming at the plateau. The equipment shipped this time includes multi-functional drilling rig, full computer rock drilling jumbo, wet spraying jumbo, arch jumbo, dust removal jumbo, etc. the product types cover the construction processes of tunnel advance geological exploration and reinforcement, excavation, support, etc. This is the first batch of CRCC, and also the first batch of domestic full process tunnel drilling and blasting construction equipment applied to plateau railway construction.

In the early stage, this batch of equipment went through repeated scientific research and demonstration, and passed the tests of extreme conditions and complex meteorology, such as high cold and high temperature on plateau, complex geological conditions, etc. The overall performance of the equipment is reliable, and it has intelligent function. It can realize the tunnel construction with fewer people, alleviate the construction efficiency and life safety of construction personnel affected by high altitude reaction, minimize the impact of railway construction on natural ecology, realize efficient, safe and green construction, stand on the top of the snow, and exert the hard nuclear combat power of "special forces".

Fast installation, fighting wind and snow

March into the western plateau, march on the cold mountains, and chisel through the ice and snow. As the basic equipment of the construction project, the plateau type concrete mixing station of China Railway Construction Heavy Industry Co., Ltd. takes the lead to complete the installation and smooth discharge in only 16 days, laying a solid foundation for the smooth completion of the whole project.

According to the urgent requirements of customers, the installation time of mixing plant is adjusted from December 25, 2020 to December 15, 2020. In order to successfully complete the installation task, from project operation, R & D, production, delivery to installation, all departments responded positively, formulated detailed node plan, reasonably arranged personnel and cooperated closely.

The project team works around the clock to install the equipment

The project is located at an altitude of nearly 4000 meters, with long sunshine time, great temperature difference between day and night, high ultraviolet intensity, and temperature up to - 15 ℃ in the morning and evening. With the nausea, chest tightness, hypoxia and vertigo caused by high altitude reaction, the on-site installation and production personnel overcame the cross construction, compact site, inconvenient accommodation, endured extreme weather such as ice and flame, worked hard day and night, cooperated and communicated closely with the customer's local project department, completed the task on time according to the task node, and reduced the production time of 18 200t powder cans on site from the standard 30 days The installation time is shortened from 26 days to 16 days, which is more than one week earlier than that in plain areas. The material will be officially discharged on December 11, 2020.

Installation of mixing plant completed

In order to ensure the stable operation of the equipment, the power, hydraulic, non-metal and transmission parts are specially designed according to the characteristics of plateau special working conditions. The equipment has the advantages of uniform mixing, high reliability, energy saving and environmental protection, and high degree of intelligence. It can realize automatic drop correction, automatic calibration, over and under balance automatic treatment, automatic material adjustment of sand moisture content, rapid formula switching and self failure Diagnosis, abnormal alarm, one button washing machine and other functions. Since the discharge, the equipment has been running stably, with a total discharge of more than 7000, which has been highly recognized by customers for its stable and reliable construction performance.

Extreme working condition, not afraid of challenge

In guigala tunnel, CRCC's plateau type wet shotcreting machine was successfully applied to overcome the extreme working conditions of 4600m plateau, helping the rapid and safe construction of line S5 in Tibet.

Plateau construction in the bad environment

Guigala tunnel is currently under construction in the world with the highest altitude and the longest mileage (12.9 km). The maximum buried depth is about 1152 meters. The left tunnel is 12878 meters long, and the right tunnel is 12945 meters long, belonging to the super long tunnel. The construction environment of guigala tunnel is harsh and the geological conditions are complex, which belongs to extreme plateau conditions. The tunnel entrance is shallow buried and rich in water, the exit is shallow buried and biased, karst, rock burst, mud burst and water gushing, as well as gas layer, high ground stress layer and radioactive layer. The harsh plateau environment and complex geological conditions make many brands of wet spraying machines unable to adapt to the normal operation, and they have broken down one after another. Through in-depth analysis of the influence of plateau environment on the equipment, CRCC has carried out plateau adaptability design for each component system of plateau tunnel construction equipment, carried out plateau environment adaptability test research, and finally formed a set of relatively mature plateau adaptability technology of tunnel construction equipment.

Plateau type wet shotcreting machine of China Railway Construction Heavy Industry Co., Ltd.

Each component system of plateau type concrete wet shotcreting machine of CRCC has been designed for plateau adaptability, and equipped with high pressure and large displacement plateau type air compressor. The equipment has independent construction capacity and does not need to rely on external air source. Since October 6, 2020, the equipment has been put into normal operation for 2 months under the plateau low pressure (68kpa) and low temperature (minimum temperature - 10 ℃), with a cumulative injection volume of more than 3000. With strong and reliable plateau adaptability and high-quality and efficient injection operation capacity, the equipment has provided safety guarantee for the rapid construction of the tunnel, and gained the recognition of customers.

The successful application of plateau type concrete mixing plant and plateau type concrete wet spraying machine of CRCC has practiced the customer first service concept of CRCC, fully verified the adaptability and reliability of equipment in plateau environment, and laid a solid foundation for CRCC tunnel construction equipment to participate more in plateau railway construction.Editor/Serena