Bridge construction is a massive and complex project. Just as building a house requires a solid foundation, bridge construction also requires proper handling of the pile - foundation process to ensure the safety of the bridge. Concrete technology plays a crucial role in bridge pile foundation construction and has positive effects in specific implementations.

Specific Measures for Bridge Pile  Foundation Concrete Construction Technology 

(1) Preparatory work in the Initial Stage

First, control of raw materials. Due to the crucial role of concrete technology in bridge pile foundations, strict quality control has already been implemented in the selection of concrete raw materials. The concrete for bridge pile  foundations is made by mixing medium - coarse sand and pebbles with cement. Among them, Portland cement should be selected, and the sediment content in the coarse sand and pebbles should be kept below 2%. Secondly, control of fluidity. For concrete, its water - retaining property and fluidity should be fully guaranteed, which is beneficial for the pouring work . Therefore, for concrete mixing, the control of the amount of water directly affects its fluidity. Thirdly, preparation for pouring. Concrete pouring for bridge piles - foundations cannot be carried out directly. Before starting of pouring, a series of preparatory work should be done. First, determine the performance indexes of the mud in the bridge pile - foundation hole. Ensure that the performance indexes of the mud can guarantee its fluidity so as not to cause landslides. Then, determine the diameter of the conduit according to the diameter of the reinforcement cage, the size and depth of the hole, and the range of movement of the conduit, and assemble and number the pouring conduits. Finally, check the bottom of the bridge pile - foundation hole to see if there is underground water and sediment at the bottom. If these are discovered at the bottom of the hole, they must be removed promptly. Settlements can be directly salvaged for sediment. In the face of underground water, it should be handled according to different situations. If there is little underground water, it can be directly absorbed with a sponge. When there is a large amount of underground water, concrete pouring underwater is required. Thirdly, time control. After ensuring the quality of the concrete raw materials, the concrete begins to pour the foundation pile - bridge. It's important to note that concrete also has a specific process for setting it. Ordinary concrete that has set for three to five hours can only meet the requirements of pile - foundations with small diameters in shallow holes. However, bridge pile foundations not only have large diameters but are also mostly deep holes. Therefore, after concrete pouring, it is necessary to wait for five to seven hours before moving on to the next step. Fourthly, control of slump height. The foundations of the bridge pile have very strict control over the slump height, usually strictly controlled within 200 - 220mm. This is to ensure that during the concrete pouring process, the pouring pile will not be blocked due to the fluidity characteristics of the concrete, thus affecting the quality of the bridge pile - foundation.

（2) Specific Construction Measures

Firstly, strengthen the strength of the retaining wall. The main function of the retaining wall is to prevent the collapse of earth and rock from endangering the construction of workers. Therefore, the strength of the retaining wall should be ensured to meet the construction requirements. Generally, the retaining wall needs to be 30cm higher than the ground to ensure its safety. At the same time, attention should also be paid to whether the underground water has an impact on the retaining wall. Then, do a good job in pouring work. Pouring concrete is a very cumbersome task. Due to the large scale of bridge projects, the amount of concrete is usually also very large. On the one hand, if the concrete cannot be poured in time and the mixing time is too long, the performance indexes of the concrete cannot be guaranteed, and segregation is prone to occur. In response to this situation, workers need to control the mixing time and degree of the concrete to improve the strength of the concrete and avoid segregation due to excessive mixing time. On the other hand, during the concrete pouring process, it is easy to generate huge resistance to the pouring conduit, damage the workability of the pouring conduit, and block the pouring conduit, making the subsequent concrete pouring more difficult. However, workers can avoid this situation by quickly increasing the pouring volume of concrete into the funnel of the equipment. Finally, control the pouring speed. Concrete pouring is not allowed to stop halfway, nor is it allowed to exceed the pouring range. Therefore, in order to ensure that the concrete pouring process can be completed in an orderly manner and to ensure the rationality of the pouring speed, workers should design the actual height of the building to be poured in advance, and during the pouring process, closely monitor the pouring work and actively cooperate with other processes.

(3) After work

Firstly, reduce the amount of concrete used in the last concrete pouring. During the last concrete pouring, due to the continuous repetition of operations in the front, the pressure in the conduit gradually decreases. Workers increase the height of the concrete column by adding water to the hole. Therefore, in order to avoid over - pouring and material waste, the amount of concrete should be reduced during the last concrete pouring. Secondly, balance the density of the concrete. In the later stage of the pouring work, due to the continuous reduction of the pressure in the conduit, the density of the concrete will increase, thus affecting the quality of the bridge pile - foundation. Therefore, in order to make the density of the concrete consistent before and after, the height of the funnel can be increased in the later stage. Thirdly, maintenance and inspection. After completing the concrete pouring work, do the corresponding maintenance work and inspection work well. The maintenance work mainly prevents the concrete from being damaged during the setting period, while the inspection work needs to use the ultrasonic transmission method to detect whether the quality is qualified and there are no other safety problems.

Construction Technology Operation Process for Bridge Pile Foundation Concrete

Firstly, workers measure the surface in this area to locate the hole's center position and set a cross - shaped guard pile at that position. Remove the debris at the hole's location, eliminate any obstructions, and flatten it. The workers began drilling operations using drilling machinery. Then, workers embed casing pipes in the drilled holes. The goal is to correct the pile position, prevent the water from flowing into the drilled holes, and protect the hole mouth and hole wall. Therefore, the design and installation of the casing pipe are highly specialized. The casing pipe's inner diameter should be at least 20cm larger than its drilled pile's inner diameter. The installation depth in the clayey soil area should not be less than 1 meter, and the sand within the range of 0.5 - 1 meter should be removed and replaced with clayey soil. The installation requirements for the casing pipe have different regulations for frozen soil, riverbeds, etc. Construction personnel should make decisions based on the situation. Next, make mud. In the drill hole, the possibility of hole - wall collapse is prone to occur. To prevent this situation, mud can be filled in the casing pipe. By using the principle that the mud density is higher than that of water, a barrier can be built on the hole wall with mud to prevent water from permeating out of the hole. However, it should be noted that there are certain requirements for selecting soil and water for mud. Tap water cannot be used, nor can clay with too much sand and a thick soil layer be chosen. Finally, establish a working frame for the drilled hole, clear the surrounding area, tamp the soil layer, enclose the hole mouth, and make good drainage facilities to drain the surface water. After completing these safety measures, personnel and materials enter the site. Secondly, use the drill bit to drill holes and clean out the residues in the holes. After the drilling is completed, check whether the drilled hole has reached the designed standard height, drain the water in the hole, which is above 1.5m of the groundwater or river water, and check the inner diameter, shape, and inclination of the drilled hole. After a series of inspections in the hole are completed, the work of digging the pile hole begins. After completing the drilling and inspection work, then start making the reinforcement cage. The making of the reinforcement cage must prioritize worker safety and the placement of materials to prevent personnel safety accidents and material loss. The reinforcement cage must also be very firm and in the correct position to avoid affecting subsequent operations. Finally, concrete pouring, and the concrete that meets the requirements is transported to the reinforcement cage through equipment to form the general structure of the bridge pile - foundation. Thirdly, inspection of bridge pile - foundations. The quality inspection of bridge pile - foundations is very important. On the one hand, check the load - bearing capacity of the pile, and on the other hand, check whether the quality of the pile meets the acceptance standard, and whether there are situations such as concrete segregation and cracks on the outer wall of the pile body.

Conclusion

All in all, concrete technology plays a significant role in bridge piles - foundation construction, and there is no room for sloppiness in concrete technology. Therefore, workers should strictly follow the concrete construction process, not use inferior materials to replace good ones, attach importance to every construction link, and ensure the quality of bridge pile foundations.