(Seeking help) Regarding foundation piling at the construction site
Thread Content
I’d like to ask some questions to the experts here, gently :) I work on site, and the soil there is very soft; therefore, piloting is necessary. I’m not very familiar with the process of piloting. How many categories are there for piloting? What is the specific procedure? Is it first to insert a rebar bar, then put wood into the foundation, and finally pour concrete? How far apart should piles be installed? Is the entire wooden structure driven into the ground, or are piles only installed where the building will be constructed? Thank you
The purpose of piling is to increase the bearing capacity of the ground. I’ve never heard of using wooden piles as foundations for structures that are meant to last a century; for other types of building foundations, precast reinforced concrete elements are used； Currently poured structures include plain concrete piles, reinforced concrete piles, concrete mixing piles, and so on. There are many methods for basic foundation treatment, such as caissons, graded sand, soil replacement (3:7 lime-soil mix), piling, concrete pouring, compaction piles, and so on; piling is just one part of foundation treatment. (Reference provided by a layperson)
Pile foundations are a common type of deep foundation, consisting of piles and cap foundations. The material for the piles can be concrete, steel, or a composite material. 1: Based on the different bearing characteristics, piles can be classified into end-bearing piles, friction-end bearing piles, friction piles, and end-bearing-friction piles. In a bearing pile foundation, the pile tip is embedded in hard soil layers; under the condition of ultimate bearing capacity, the loads from the superstructure are transmitted to the soil at the pile tip through the pile ； Friction piles rely on the friction between the soil beside the pile and the pile itself to support the loads above; they are commonly used in areas with thick layers of soft soil. II: Classified by their functional use, piles can be divided into vertical compressive piles, vertical tensile piles, horizontally loaded piles, and composite-loaded piles. III: Based on the construction method, they can be divided into precast piles and cast-in-place piles. Precast piles are piles of various forms that are manufactured in factories or at construction sites, and then driven into the ground using methods such as hammering, static pressure, vibration, or water jetting. Generally, there are precast concrete piles and steel piles. Piled foundations involve drilling holes on-site, then placing a rebar cage in the holes and pouring concrete to form the pile. Based on the method of hole formation, driven piles can be further divided into methods such as drilling, excavation, jetting, and pipe sinking. Depending on the hole-forming process, they are classified into dry-hole formation, mud-wall-supported hole formation, casing-based hole formation, and explosive expansion hole formation, among others. In engineering, the pile type and construction method are generally determined based on the soil conditions, surrounding environment, and upper loads. Piles with a diameter d ≤ 250 mm are referred to as small-diameter piles ； 250mm