Project Introduction

Recently, the Wenzhou Municipal Solid Waste Incineration Fly Ash Resource Utilization Project, contracted for construction by Wenzhou Jingjiu Foundation Engineering Co., Ltd., adopted the large-diameter down-the-hole (DTH) hammer construction method. This not only tackled a highly difficult construction challenge but also created engineering speed, earning high praise from the client. The project is a environmental protection supervision project of Zhejiang Province, located at the junction of Lingtou Village, Guoxi Subdistrict, Ouhai District and Tianchang Village, Zeya Town. The construction site is a valley area formed by the convergence of several valleys. The upper stratum of the project consists of accumulated landfill waste with a large fill thickness, while the lower stratum is a rock-soil structure with complex geology and hard rock. In response to the special geological structure and ecological environment, the project department boldly adopted large-diameter DTH drilling rigs, with a pile diameter of φ800 and a drilling depth of more than 30 meters, completing the hole in a single pass. The large-diameter DTH hammer method not only ensured the construction quality of the pile foundation works but also greatly improved work efficiency, delivering good economic and social benefits.‍

Method Features

01. Achieving Efficient Rock Penetration

Solving the technical challenge of efficient "rock penetration" for large-diameter piles: it can form holes in special complex strata such as cobble and boulder layers and hard rock layers, with good pile quality and high construction efficiency, solving the technical challenge of efficient "rock penetration" for large-diameter pile foundations.

02. New Energy-Saving and Emission-Reduction Process

Solving the problem of serious environmental pollution caused by mud wall protection in pile holes: no mud wall protection is required, with no pollution from mud preparation and discharge, and a clean site. It fills a domestic technical gap and is a new environmentally friendly piling machinery product and process that meets the national policy requirements for energy conservation and emission reduction, with good economic and social benefits and broad market application prospects.

03. Solving the Common Defect of Mud Inclusion

Solving the common defect of mud inclusion during concrete pouring: the upper and lower power heads rotate in opposite directions for drilling, the DTH hammer has a high impact frequency, crushing rock with low amplitude and high frequency, and the full casing follows up for wall protection, avoiding collapse risks and eliminating the common defect of mud inclusion during concrete pouring.

04. Suitable for Various Complex Geologies

Suitable for various complex and special geologies: pile foundation construction mainly in fine sand layers, gravel layers, quicksand, underground rivers, flow-plastic silt, karst caves, hard rock layers and high groundwater levels, greatly improving project progress and construction quality.  

05. Achieving Multiple Functions with One Machine

Multi-functional drilling rigs achieve multiple functions with one machine: featuring single-machine multi-function, multi-purpose and diversified construction. It can reduce equipment investment and improve equipment utilization, creating higher equipment use value and economic benefits for customers while also creating good social benefits.‍