360° all-round high-pressure grouting jet construction, maximum construction depth up to 100m, pile diameter up to 2-2.8m, initial grout jet pressure up to 40MPa, added in-ground pressure monitoring, reduced ground pollution... Recently, Shanggong Machinery's new ultra-high pressure jet grouting equipment—the SMJ-120 crawler-type ultra-high pressure jet grouting rig—appeared at a new project in the east area of Shanghai Center. To solve construction challenges in urban infrastructure development, it breaks hard rock with fervor, demonstrating the style of the century-old Shanggong national brand.

▲SMJ-120 crawler-type ultra-high pressure jet grouting rig at the construction site

Recently, good news has been pouring in from the new project in the east area of Shanghai Center. To achieve a water-stop effect at the joints of the underground diaphragm wall, the project adopted Shanggong Machinery's SMJ-120 crawler-type ultra-high pressure jet grouting rig to construct 120 jet grouting piles on the side of the underground diaphragm wall, including 6 full-circle 360° piles and 114 half-circle 180° piles, with a maximum pile depth of 45.8m, pile diameter of 2.4m, and pile spacing of 5m. The surrounding environment of the proposed site is relatively complex. With construction advantages such as large pile diameter, good pile quality, less mud pollution, and small impact on the surrounding environment, the SMJ-120 crawler-type ultra-high pressure jet grouting rig secured success with stability and became the main machine for this project.

▲SMJ-120 crawler-type ultra-high pressure jet grouting rig at the construction site

▲Matching high-pressure mud pump, automatic slurry mixing system, and air compressor

▲Guide hole drilling rig performing guide hole construction

Engineering designer: East China Architectural Design & Research Institute General Institute

Engineering contractor: Shanghai Siyao Construction Group Co., Ltd.

It is reported that the proposed Baoneng West Shanghai Center East Area New Project (formerly Jianpeilong plot) is located in Putuo District, Shanghai, south of Cao'an Road, east of Zhenguang Road, and west of Zhenbei Road (Middle Ring Road). The project covers an area of 47,000 m², with a total construction area of about 218,000 m². The project plans to demolish the original four unfinished buildings about 100m high and 1-2 story basements on the site and rebuild a commercial complex.

The foundation pit boundary of the proposed site is about 5m from the red line of the northern road, 10-15m from the boundary of the western commercial building, 15m from the boundary of the southern commercial building, and within 10m from the red line of the eastern road. The surrounding environment of the proposed site is relatively complex. Through in-ground pressure detection and forced mud discharge, the SMJ-120 crawler-type ultra-high pressure jet grouting rig monitors underground mud pressure in real time, which can greatly reduce the impact on the surrounding environment and successfully complete the construction requirements of the construction unit.

SMJ-120 crawler-type ultra-high pressure jet grouting rig

The construction principle of the SMJ-120 crawler-type ultra-high pressure jet grouting rig uses three media: high-pressure water, high-pressure air, and high-pressure cement slurry. Through a unique multi-hole pipe and front-end forming device, it uses high-pressure jets to cut and break the surrounding soil. It takes a series of processes—pressurized delivery of hardening material slurry, jetting, cutting the stratum, mixing, mud discharge, mud collection, and mud transport—as monitoring objects. It is a construction device capable of horizontal, vertical, inclined, and 360° all-round foundation reinforcement. The biggest feature of this equipment's construction is the realization of forced mud discharge in the hole and the control of in-ground pressure by adjusting the mud discharge volume, effectively suppressing foundation heave or settlement caused by jet mixing and greatly reducing environmental impact.

▲SMJ-120 crawler-type ultra-high pressure jet grouting rig

▲Construction process of the SMJ-120 crawler-type ultra-high pressure jet grouting rig

SMJ-120 crawler-type ultra-high pressure jet grouting rig

·All-round high-pressure grouting jet construction

Achieves horizontal, vertical, inclined, and 360° all-round construction;

·Large pile diameter and good pile quality

The initial grout jet pressure reaches 40MPa, with a flow rate of 90-130L/min. When using a single nozzle, the average lifting speed is 2.5-3.3cm/min. The jet flow capacity is large, and the operation time is long. Accompanied by a stable 0.7MPa coaxial cylindrical high-pressure air protective jet and adjustment of in-ground pressure, the MJS method produces a relatively large pile diameter, up to 2-2.8m (sand N<70, clay C<50), and the pile body is uniform and of good quality;

·Large reinforcement depth

The maximum construction depth can reach 100m. Because the front-end cutting device is equipped with an in-ground pressure sensor and a multifunctional multi-hole pipe (water-air composite forced mud discharge), the jetting conditions are always in the optimal state, making ultra-deep construction possible;

·Higher construction efficiency

The whole machine is equipped with a crawler travel system, making relocation flexible. It does not require large-tonnage crane lifting and shifting, resulting in higher efficiency. It can perform construction under harsh conditions such as low headroom, and the range of applicable working conditions is wider.

·Less mud pollution

Because a dedicated mud pipe is used for mud discharge, it facilitates centralized mud management and reduces ground mud pollution; in-ground pressure detection is added to prevent mud from spreading to the surroundings;

·Small impact on the surrounding environment

Through in-ground pressure detection and forced mud discharge, underground mud pressure is monitored in real time, which can greatly reduce the impact on the surrounding environment.

In addition to the ultra-high pressure jet grouting main machine and drilling tools, we can also provide supporting services for all equipment required for construction, such as guide hole drilling rigs, high-pressure mud pumps, high-pressure water pumps, air compressors, automatic slurry mixing systems, and mud filter presses. We also provide construction training and construction guidance services, offering a one-stop solution to construction equipment and operation issues, lowering the entry threshold, and enabling customers to earn big money easily.