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→Design
* Mixing can be done on a paved surface using front end loaders. Typically the stone is spread in a layer, the dry hydrogel is spread evenly on top and the screened moist clay loam soil is the top layer.
* Mixing can be done on a paved surface using front end loaders. Typically the stone is spread in a layer, the dry hydrogel is spread evenly on top and the screened moist clay loam soil is the top layer.
* The entire pile is turned and mixed until a uniform blend is produced. The structural soil is then installed and compacted in 150 mm lifts.
* The entire pile is turned and mixed until a uniform blend is produced. The structural soil is then installed and compacted in 150 mm lifts.
====Structural Concrete Panel====
* Structural concrete panel is 250 mm thick, contains rebar reinforcements and sits on equal-sized concrete footing supports on rows of modular soil support structures, which are supported by a minimum 150 mm base of compacted granular material.
* Decompact native subgrade soil under tree openings and between granular bases of modular soil support structure rows during installation for better infiltration drainage performance.
====Aggregate Base====
* Aggregates are used in modular soil support systems below the structures as the trench base layer, and in some cases, on top of the structures, as the pavement base layer.
* Specifications for aggregate base materials and depths shall be determined by the designing Engineer based on structural loading and hydraulic requirements.
====Geotextile and Geogrid====
* Geotextile, geogrid or combinations are typically used on top of modular soil support structures and along the sides of the trench to separate growing or structural soil mediums from native soil or aggregate backfill.
Geotextile and geogrid should not be installed on sides adjacent to pervious landscaped areas to provide opportunities for tree roots to grow outside the trench in these locations.
* Geotextile, geogrid or combination products in contact with modular soil support system structures should be according to manufacturer’s specifications.
* Geotextile material specifications should conform to Ontario Provincial Standard Specification (OPSS) 1860 for Class II geotextile fabrics.
* Geotextile installed on tree trench sides and around perforated distribution and underdrain pipes should be woven monofilament or non-woven needle punched fabrics. Woven slit film and non-woven heat bonded fabrics should not be used as they are prone to clogging.
* Where a root barrier is needed to prevent the migration of roots out of the tree trench, use impermeable ribbed barrier material with a thickness of 1-2 mm.
====Underdrain Pipe====
* Should be minimum 150 mm dia. perforated HDPE or equivalent material, smooth interior wall and continuously perforated with geotextile sock.
* A standpipe from the underdrain pipe to the growing medium or pavement surface can be used for inspection and maintenance. The top of the standpipe should be covered with a sealable cap and secured with a vandal-proof fastener.
Stormwater Distribution Pipe
* Solid pipe from inlet structures should transition to perforated pipe once 300 mm inside the trench.
* Perforated pipe should be minimum 150 mm dia. rigid, smooth interior wall HDPE or PVC with perforations on sides, wrapped with geotextile sock, with capacity and perforation specifications confirmed by the designing Engineer based on hydraulic requirements.
==Soil cells==
==Soil cells==