Maccaferri Philippines helps prevent land erosion at a ICTSI plant in by using gabions and mattresses
The International Container Terminal Services Inc. (ICTSI) has a large inland container terminal in San Cristobal, Calamba, Laguna. As ICTSI seeks to expand and upgrade facilities at the site, optimizing and protecting land assets has become a significant issue.
The southern and western boundaries of the site sit on the San Cristobal River. Heavy rainfall and flood conditions in the river have already eroded a significant section of land.
Working closely with consultants from Hong Kong and site engineers, Maccaferri Philippines Inc. proposed measures to prevent further erosion using gabions, mattresses, concrete block mattresses, MacMat R reinforced 3D erosion mat and MacFormer grout mattresses deployed along the lower portion of the riverbank (you can download our Technical Document).
Maccaferri’s filter point grout mattress (MFMII– F300) was recommended for the erosion protection at the lower portion of the slope and Maccaferri’s (MacMat R) was proposed for the upper slope portions.
This was not a simple design; working closely with ICTSI’s own consultants, analysis of soil conditions, hydraulic forces in the river and maximum water levels experienced during heavy rainfall, typhoons and tropical storms all had to be considered in arriving at a suitable and effective design.
The final design used concrete block mattresses installed at the toe of the riverbank slopes. This was achieved by building a temporary coffer dam to make it easier to install the mattresses. At the same time, slope preparation with compacted gravel was done to profile the slope at 27 degrees in preparation for the MacFormer Grout Mattress. A roll length of 50 meters allowed for a 2-3-meter overlap at the toe of the slope and sufficient material to overreach the top of the slope and drop into an excavated trench to secure the mattress. This allowed for approximately 35-to-40-meter length of mattress to cover the riverbank.
After delivery of the mattresses to the site, each was carefully laid out allowing for shrinkage when filled. A hand held sewing machine was used to close the lower portion of the MacFormer mattress. Concrete, sourced from a nearby batching plant, was delivered to site and pumped into the mattress allowing each unit to fill from the bottom up. Since this installation was on a long slope, care was taken to use concrete with a higher slump. Pumping was done slowly to ensure even filling and to reduce the chance of bursting due to high pressure.
On completion of installation of the MacFormer Grout mattress (Type II), the upper slope of the riverbank will be profiled at 35 degrees before covering with Maccaferri MacMat R reinforced geomat made from a polymer matrix extruded onto a double twisted steel woven mesh. In the fullness of time, this slope will vegetate further enhancing the effectiveness and appearance of the MacMat R.
Both consultants and the client considered MacFormer MFM II to be an easily deployed and highly effective solution delivered at cost below many other erosion control systems. It’s ability to conform to slope geometry while resisting hydraulic forces that may impact on the structure made this a highly successful installation.