Method and apparatus for forming a trench

A trench forming assembly and removable form for forming a trench of predetermined shape is disclosed according to the present invention. The removable form includes an elongate form body having top, bottom and opposed side surfaces and first and second elongate form removal slots extending upwardly from the bottom surface of the form body. Preferably the removable form has a top surface defining a complex shape including at least a first upwardly extending ear portion which extends longitudinally along the top surface. At least a first form removal slot of this elongate form body extends into a portion of the first ear portion. Advantageously, the form body includes a pair of coplanar elongate slots integrally formed in the side surfaces for receiving a pair of frame members in a predetermined coplanar, spaced relationship above the bottom surface of the form body. In another embodiment, a removable form includes a second elongate form body portion extending laterally along one side surface of the elongate form body and having a predetermined shape for forming a structure having a corresponding shape, such as a curb.

FIELD OF THE INVENTION 
The invention relates to methods and apparatus for forming trenches. More 
particularly, the invention relates to methods and apparatus for forming a 
trench with a removable form body. 
BACKGROUND OF THE INVENTION 
Drainage and other trenches of various sizes and shapes are desirable for 
numerous applications. For example, manufacturing facilities typically 
require drainage systems which include trenches formed in the building 
floors to collect, remove and/or recycle excess water or other liquids. In 
addition, numerous outdoor industrial and commercial sites, such as 
parking lots, require drainage systems, including trenches, to collect and 
direct rainwater and other liquids to underground storm sewers to prevent 
flooding and to decrease runoff. 
In the past, these trenches have generally been formed by first placing and 
securing a form of predetermined shape in a ditch which has previously 
been formed in the ground. A moldable trench forming composition, such as 
cement, concrete, or the like is then poured around the form and is 
allowed to set. Once the concrete has set, the form is removed from the 
resulting trench. 
One common type of form assembly used to define a trench includes a wooden 
frame and strut structure. The wooden form includes a wooden frame which 
is covered with wooden sheets or planks to define a generally rectangular 
elongate trough. The wooden form is typically enclosed along its side and 
bottom faces, but may have an open top. Typically, a number of supporting 
wooden ribs are installed within the wooden form to increase the strength 
of the form so that it can withstand the relatively large pressures 
exerted by moldable trench forming compositions poured about it. 
The wooden form is placed and secured within a preformed ditch. Concrete is 
typically poured up to the bottom face of the form and allowed to set. 
Then additional concrete is poured between the earthen walls of the ditch 
and the wooden sides of the form. Once all of the concrete has set, the 
wooden form is disassembled and removed from the trench. 
Wooden forms are generally formed of lumber having a relatively rough 
exterior texture. Correspondingly, the inside surface of the trench formed 
by the wooden form is relatively uneven which reduces the efficiency of 
the flow of liquid through the trench. In addition, the assembly and 
disassembly of the wooden forms is both costly and labor intensive. The 
relatively large cost and labor required for assembly and disassembly of 
the wooden forms is increased in the formation of long trenches, and even 
further increased in the formation of trenches having a pitched or slanted 
bottom surface to facilitate drainage. 
It is normally desirable to finish the trench with an elongate grate 
covering its open top in order to prevent people from unwittingly stepping 
in the open trench, to provide a smooth surface for vehicle travel, and/or 
to prevent relatively large objects from entering the trench and 
potentially blocking the flow of liquid therethrough. The grate is 
generally supported by a pair of spaced apart frame members which are set 
into and extend from the walls of the concrete trench. In order to 
stabilize the grate and to prevent the grate from rocking when weight, 
such as from a passing vehicle, is applied thereto, the frame members must 
be aligned in a common plane during the pouring and setting of the 
concrete about the form. If the grate is not properly aligned, the grate, 
the frame members and/or the concrete trench itself may be damaged by the 
resulting movement of the grate. If the grate rocks excessively, the grate 
may even be dislodged from the frame members thus leaving the trench 
exposed. Accordingly, the alignment of the frame members in the moldable 
trench forming composition is both important and laborious. 
In an attempt to properly align the frame members without laborious manual 
alignment, precast trench assemblies have been developed. Precast trench 
assemblies generally include preformed metal and/or plastic assemblies 
designed to be placed in a preformed ditch. Moldable trench forming 
composition may thereafter be poured about the precast trench assembly. 
Once the trench forming composition has set, the precast trench assembly 
is securely bonded to the trench forming composition to stabilize and 
support the trench. Precast trench assemblies, however, are relatively 
expensive and may only be used once. 
Commercially significant methods and apparatus for forming trenches, 
together with improved removable forms for forming trenches, are disclosed 
in U.S. patent application Ser. No. 07/768,610 to Stegell filed Sep. 26, 
1991. In advantageous embodiments thereof inexpensive forms are employed 
to form trenches having properly aligned frame members. 
The trench forming assembly disclosed in U.S. patent application Ser. No. 
07/768,610 preferably includes longitudinal frame members having a 
plurality of anchoring rods extending downwardly from the frame members. 
An elongate form body, preferably formed of relatively lightweight 
expanded polystyrene, generally includes aligned longitudinal slots in the 
opposed side walls for receiving the frame members. Horizontal portions of 
the frame members are secured within the longitudinal slots in the 
sidewalls of the form body during formation of the trench so that the 
frame members are held in alignment during the trench forming operation. 
Preferably the assembled form and frame members are placed into a prepared 
ditch by suspending the assembly from its top. Concrete is first poured 
around the bottom of the anchoring legs attached to the frame members and 
allowed to set. Then concrete is poured around the form body and allowed 
to set. Finally the form body is removed to expose the resulting trench 
and the properly aligned frame members. The removal of the form is 
preferably facilitated by a pair of slots extending a relatively short 
distance into the form body from its bottom surface. Wires are provided in 
the slots and, once the trench forming composition has set, are pulled 
upwardly through the form. The form body is thereby cut into several 
pieces that can be more easily removed from the trench. 
SUMMARY OF THE INVENTION 
The present invention provides improved trench forming methods and 
apparatus. In one aspect the invention provides form bodies which can be 
readily removed from the trench upon setting of the moldable trench 
forming composition without requiring the use of wires for cutting the 
form into pieces prior to its removal. In other aspects, this invention 
provides a trench forming assembly which allows the removable form to be 
readily aligned and suspended within a preformed ditch. The invention also 
provides form bodies for simultaneously forming structures, such as curbs, 
adjacent to the trench. 
In a first aspect, the invention provides improved forms for forming 
trenches of predetermined shapes which can be readily and efficiently 
removed following the trench forming operation. In accordance with this 
aspect, an elongate form body having a bottom surface and opposed side 
surfaces for defining the shape of the trench, includes means formed along 
the opposed side surfaces of the form body for engaging a pair of frame 
members defining a support surface for supporting a trench cover. The form 
body also includes first and second form removal slots which extend within 
the form body longitudinally from end to end and upwardly from the bottom 
surface thereof to a location below the top surface of the form and above 
the location of the frame members engaged by its side surfaces. Following 
use of the form body to form a trench, a portion of the top of the form 
body can readily be removed, as by a cutting operation or the like to 
expose the top of the form removal slots and thereby separate the form 
body into pieces which can easily be removed from the newly formed trench. 
In another advantageous embodiment, a removable form body of the invention 
includes an upper surface having a complex cross-sectional shape including 
at least one upwardly extending ear which extends above at least one lower 
portion of the top surface and which also extends longitudinally along the 
top surface. At least one form removal slot within the form body extends 
upwardly into a portion of the ear so that the top of the form removal 
slot can be exposed by cutting or removing the ear portion of the form 
body, as by cutting or scraping along the top of the form body. 
In another embodiment of the invention, the top surface of the form body 
also includes a second upwardly extending ear which also extends upwardly 
above the lower portion of the top surface and longitudinally along the 
length of the form body. The two upwardly and longitudinally extending 
ears are advantageously spaced laterally from each other to define a 
central recess extending longitudinally along the top of the form body. 
Advantageously, the central recess is substantially rectangular in 
cross-section and is of a predetermined size for receiving an alignment 
member of like cross-section. One preferred alignment member can be 
framing lumber of a conventional cross-section of about 2 in. by about 4 
in. An alignment member which has been properly aligned and anchored in a 
suspended position over a prepared ditch can be secured into the central 
recess of the form to readily support and align the form in the ditch. 
In embodiments of the invention wherein the top surface of the form body 
includes two upwardly extending ears, each of the form removal slots 
preferably extend upwardly into a portion of one of the ears. 
Advantageously, each of the form removal slots extends upwardly at least 
1/4 inch into each of the ears. 
The first and second form removal slots preferably define, in transverse 
cross-section, a truncated V-shaped wedge portion of the form body. The 
V-shaped wedge portion of the form body is integrally joined to other 
portions of the form body by a portion of the top of the form body. The 
upwardly extending form removal slots diverge such that the lateral 
spacing therebetween increases in an upward direction from the bottom 
surface of the form body toward the top surface. i.e. the truncated 
V-shaped portion of the form body is oriented in an upright position. The 
lateral spacing between the first and second form removal slots at the 
bottom surface of the form body is preferably less than about 1.5 inch so 
that only minimal fluid pressure is applied to the bottom of the wedge by 
concrete or other unset trench forming material. Advantageously, the 
diverging first and second form removal slots define an angle of between 
about 5.degree. and 45.degree.. 
In various preferred embodiments of the invention, the means for securing 
the frame members to the sides of the form body comprise a pair of 
coplanar elongate slots integrally formed in the side surfaces of the form 
body. Preferably at least one of the form removal slots extends upwardly 
above the elongate slots by at least about 1/4 inch. 
In yet another embodiment of the present invention, the removable form body 
also includes a second elongate body portion that extends and laterally 
outwardly along at least one side surface of the elongate form body and 
which has a predetermined external shape for forming a surface having a 
corresponding shape adjacent the trench. The second elongate body portion 
is preferably integrally joined by a portion of form material to the top 
surface of the elongate form body. Advantageously, the external shape of 
the second portion of the form body defines a curb of a corresponding 
predetermined shape adjacent to and aligned with the trench. 
The form bodies and trench forming assemblies of the present invention 
simplify the trench forming operation because the forms can readily be 
removed from a finished trench without requiring cutting wires to be 
supplied in the form. In preferred embodiments, the alignment recess along 
the top of the form simplifies the process of aligning a trench forming 
assembly within a preformed ditch or other location. Moreover the 
invention also allows for the simultaneous formation of other structures 
such as curbs or the like, adjacent the trench.

DETAILED DESCRIPTION OF A PREFERRED EMBODIMENT 
Various methods and apparatus embodiments of the invention are set forth 
below. While the invention is described with reference to specific 
preferred methods and apparatus including those illustrated in the 
drawings, it will be understood that the invention is not intended to be 
so limited. To the contrary, the invention includes numerous alternatives, 
modifications and equivalents as will become apparent from consideration 
of the foregoing discussion and the following detailed description. 
FIG. 1 illustrates an assembly 10 for forming a trench of a predetermined 
shape. The trench forming assembly 10 includes an elongate form body 12 
and a pair of frame members 14. The elongate form body 12 includes a top 
surface 12a, a bottom surface 12b, and opposed side surfaces 12c for 
forming a moldable trench forming composition into a trench of 
predetermined shape. The removable form also includes first and second 
form removal slots 16 extending upwardly into the form body from the 
bottom surface 12b thereof. 
As illustrated in the drawings, the top surface 12a of the form body 
defines in transverse cross-section, a complex shape, including at least a 
first upwardly extending ear portion 18. The first ear portion 18 extends 
upwardly above at least one lower portion 20 of the top surface 12a and 
longitudinally along the top surface 12a. One of the form removal slots 16 
extends into a lower portion of the first ear 18. 
As seen in FIG. 1 the top surface 12a of the form body 12 further includes 
a second upwardly extending ear 18 that also extends upwardly above a 
lower portion 20 of the top surface 12a of the form body and 
longitudinally along the top surface 12a. The second form removal slot 16 
extends upwardly into a lower portion of the second ear 18. Preferably, 
each of the first and second form removal slots extends at least about 1/4 
inch upwardly into the lower portion of one of the ears 18. 
As illustrated in FIG. 1, the first and second form removal slots 16 
define, in transverse cross-section, an interiorly located truncated 
V-shaped wedge portion 22 of the form body. The truncated V-shaped wedge 
portion 22 is integrally joined to corresponding lateral portions 24 of 
the form body 12 only by portions of the form body adjacent its top 
surface 12a and which also join the ears to the main portion of the from 
body. 
The first and second form removal slots 16 extend longitudinally from end 
to end of the form body. The slots 16 extend upwardly into the form body 
in a divergent arrangement. Preferably the slots diverge in a vertical or 
upward direction such that the lateral spacing between corresponding 
horizontal portions thereof increases from the bottom surface 12b of the 
form body towards the top surface 12a. Preferably, the first and second 
form removal slots 16 define an interior angle 25 (FIG. 3) of between 
about 5.degree. and about 45.degree.. 
Advantageously, a relatively small lateral spacing is provided between the 
first and second form removal slots 16 at the bottom surface 12b of the 
form body. Preferably, the lateral spacing between the first and second 
form removal slots 16 at the bottom surface 12b of the form body is less 
than about 1.5 inch. The limited lateral spacing between the first and 
second form removal slots 16 at the bottom surface 12b of the form body 
decreases the magnitude of the upward hydraulic forces imparted by the 
fluid trench forming composition on bottom of the V-shaped wedge portion 
22 as discussed more fully below. 
As illustrated in FIG. 1, the inside edges of the first and second ears 18 
and a lower portion 20 of the top surface 12a between the first and second 
ears 18 cooperate to define a central recess 12a of substantially 
rectangular cross-section of predetermined size. The central recess 26 
extends longitudinally along the top surface 12a of the form body and is 
sized to receive an alignment member 28 of like cross-section as 
illustrated in FIG. 2. Preferably, the upper surface 30 of each of the 
first and second ears 18 is spaced a predetermined distance, preferably at 
least about two inches above the lower portion 20 of the top surface 12a 
to receive the alignment member 28, such as a piece of framing lumber 
measuring about 2 in..times.4 in. in transverse cross-section. 
Advantageously, the removable elongate form body 12 includes means formed 
along the opposed side surfaces 12c for engaging the frame members 14 with 
the removable form. The engaging means are preferably provided in the form 
of a pair of horizontal coplanar slots 38 spaced above the bottom surface 
12b of the form body. Such engagement slots 38 are discussed in detail in 
the aforementioned U.S. patent application Ser. No. 07/768,610 to Stegall. 
The entire disclosure of U.S. patent application Ser. No. 07/768,610 is 
hereby incorporated by reference. Various details disclosed in the 
incorporated patent application are not repeated herein for the sake of 
brevity. However, reference may be had to the incorporated patent 
application for such details. 
As illustrated in the drawings the form removal slots 16 extend from the 
bottom surface 12b of the form body upwardly above the top of the frame 
members 14. Preferably, each of the form removal slots 16 extends upwardly 
above the top of the frame members 14 for a distance of at least about 1/4 
inch. 
The frame member engagement slots 38 defined in the opposed side surfaces 
12c of the form body are advantageously coplanar for receiving and 
maintaining the frame members in a predetermined coplanar, spaced 
relationship above the bottom surface 12b of the form body. The first and 
second frame member engagement slots 38 advantageously extend 
approximately 3/8 inch into the first and second side walls, respectively. 
As illustrated in FIG. 1, the removable elongate form body 12 preferably 
includes a top surface 12a including at least a first ear portion 18 and 
also side surfaces having engaging means for engaging a pair of frame 
members. 
The frame members 14 define a surface for supporting a trench cover 48 and 
typically serve directly as a support surface for the trench cover 48. 
Alternatively, the frame members can function as shaping elements for 
shaping the hardenable trench forming composition into a pair of recesses 
for receiving a trench cover 48, in which case the frame members 14 are 
removed to expose the trench cover receiving recesses following hardening 
of the trench forming composition. Further discussion of such removable 
frames members is provided in considerable detail in U.S. patent 
application Ser. No. 07/768,610 filed concurrently herewith entitled 
"TRENCH FORMING ASSEMBLIES HAVING ENHANCED ANCHORING MEANS" which is 
hereby incorporated by reference. 
As illustrated in FIG. 1, each of the frame members 14 preferably includes 
a horizontal elongated portion 40a adapted for insertion in the first and 
second longitudinal form alignment slots 38, respectively. 
The frame members 14 also preferably include a plurality of anchoring legs 
42, typically formed of rebar, extending downwardly therefrom. As 
subsequently discussed, the plurality of legs 42 are adapted to anchor the 
form body in a subslab 46 of moldable trench forming composition poured 
around the lower portion 20 of each of the legs 42 and below the bottom 
surface 12b of the form body. 
As illustrated, the frame members 14 also preferably includes a plurality 
of additional anchors 43 extending outwardly and downwardly from both the 
first and second frame members 14. These anchors 43 are adapted to extend 
into and be engaged by the hardenable trench forming composition poured 
about the removable form as illustrated in FIGS. 7-9. These anchors 43 
further facilitate the retention of the frame members 14 within the trench 
formed of hardenable trench forming composition. 
A preferred embodiment of the elongate frame members 14 is illustrated in 
FIG. 1. In this embodiment each frame member includes an elongate 
horizontally oriented leg 40a and an elongate vertically oriented leg 40h 
affixed, along a first edge, to the horizontal leg 40a. The elongate 
horizontal leg 40a is adapted for insertion in a longitudinal form 
alignment slot 38. The elongate horizontal leg 40a also is adapted to 
define a support surface for supporting the trench cover 48 placed over 
the resulting trench. The elongate vertical portion 40b contacts the form 
body 12 upwardly along a side surface 12c thereof following engagement of 
the frame member into the slot 38. 
Alternate embodiments of the elongate frame members 14 are illustrated in 
FIGS. 12 and 13. In FIG. 12, the first and second frame members 14 are 
comprised of an elongate upper horizontal leg 40c and an elongate vertical 
leg 40d extending downwardly from the elongate upper leg 40c and also 
include an inwardly extending removable tab or tang 40e. The elongate 
upper leg 40c is adapted for supporting the trench cover 48 placed over 
the resulting trench. As illustrated, the elongate vertical leg 40d 
extends along a side surface 12c of the form body when the frame member is 
engaged by the form body. 
The inwardly extending removable tab or tang 40e is shown in engagement 
within a longitudinal slot 38 defined in a side surface 12c of the form 
body. Upon removal of the form body following formation of the trench, the 
tab 40e may also be detached, thus leaving a relatively planer side leg. 
It will also be seen that the first and second elongate rails 14 of FIG. 
12 also preferably include a raised edge portion 40f. The raised edge 
portion 40f extends longitudinally along an outer edge of each horizontal 
elongate upper leg 40c and functions to align and stabilize a trench cover 
48. 
In yet another embodiment illustrated in FIG. 13, the first and second 
elongate rails 14 each include horizontal elongate upper 40g and lower 
legs 40h interconnected by an elongate vertical leg 40i. The elongate 
vertical leg 40i extends along a side surface 12c of the form body and 
interconnects the upper 40g and lower legs 40h such that the upper and 
lower legs extend outwardly in opposite directions from the vertical leg 
portion 40i. As illustrated, the lower leg 40h is adapted for insertion in 
a longitudinal slot 13e defined in a side surface 12c of the form body. 
Other frame members not specifically shown can also be used in the 
invention, such as for example a frame member like that shown in FIG. 1 
but having a series of removable tangs spot welded or filet welded onto 
the front edge of the horizontal leg 14a of the frame member. This allows 
the tangs to be inserted into the slot in the form and broken off 
following formation of the trench, with the result that the overhanging 
portion of the frame member shown in FIG. 10 is eliminated. 
In one embodiment of the present invention, the removable form also 
includes a second elongate form body portion 49 as illustrated in 
cross-section in FIG. 11. The second elongate form body portion 49 extends 
laterally along at least one side surface 12c of the main or 
trench-shaping portion of elongate form body 12. Preferably, the second 
elongate form body portion 49 also extends above the lower portion 20 of 
the top surface 12a and is integrally joined by a portion of the form 
material of the top surface 12a to the main portion of the elongate form 
body 12. 
The second elongate form body portion 49 has a predetermined external shape 
adapted for forming a surface having a corresponding shape. Preferably the 
external shape of the second elongate form body portion 49 is adapted for 
shaping a curb of predetermined shape adjacent to the trench. Accordingly, 
a trench and an adjacent curb may be simultaneously formed from a unitary 
removable form so as to accurately align the curb and trench. 
As illustrated in FIG. 11, the anchoring leg 42 underlying the second 
elongate form body portion 49 preferably extends angularly outward from 
the corresponding frame member 14. This outward angular extension of the 
underlying anchoring leg 42 provides additional support for the hydraulic 
forces imparted by the trench forming composition of the overlying second 
form body portion 49. 
FIGS. 2-9 illustrate use of the trench forming assemblies of the invention. 
In use, the elongate form assembly is placed in a predetermined location, 
such as a preformed ditch as illustrated in FIG. 2. The form assembly 
preferably includes frame members 14, an elongate form body 12, means 
formed on opposed side surfaces 12c of the form body for engaging the 
frame members 14 with the removable form and first and second form removal 
slots 16 extending upwardly from the bottom surface 12b of the form body. 
As previously explained, the form removal slots 16 preferably extend 
upwardly above the frame members 14 to define, in transverse 
cross-section, a truncated V-shaped wedge portion 22 of the form body 
integrally joined to corresponding lateral portions 24 of the form body by 
at least a portion of the top surface 12a. 
The elongate form assembly is thereafter anchored in the ditch. Preferably, 
the form assembly is anchored by pouring a subslab 46 of hardenable trench 
forming composition, such as concrete, in the ditch. The subslab 46 is 
poured about a lower end of a plurality of legs 42 and below the bottom 
surface of the form body as illustrated in FIG. 4. Once the subslab 46 has 
hardened or set, the frame members 14, as well as the removable form 
engagedly retained by the frame members 14, are held in a fixed relation 
with the ditch. 
Subsequently, additional hardenable trench forming composition is poured 
between the bottom and opposed side surfaces 12c of the removable form and 
the earthen walls of the ditch. In the embodiment illustrated in FIG. 6, 
the trench forming composition preferably fills the ditch about the form 
body up to the uppermost portion of the elongate horizontal leg 40a of the 
frame members 14. 
Once the hardenable trench forming composition has hardened or set, the 
elongate form body 12 is removed. More particularly, the elongate form 
body 12 is removed by first removing the truncated V-shaped wedge portion 
22 formed by the first and second form removal slots 16 and then removing 
the corresponding lateral portions 24 of the form body. As illustrated in 
FIG. 7, the truncated V-shaped wedge portion 22 is preferably removed by 
severing at least a portion of the top surface 12a of the form body which 
integrally joins the truncated V-shaped wedge portion 22 to the 
corresponding lateral portions 24. Following severance of those portions 
of the top surface 12a, the truncated V-shaped wedge portion 22 may be 
removed as illustrated in FIG. 8. Once the truncated V-shaped wedge 
portion 22 has been removed, the corresponding lateral portions 24 may be 
disengaged from the longitudinal slots 38 in the form body and removed 
from the trench as illustrated in FIG. 9. 
Thereafter, a trench cover 48, such as a grate, may be placed upon a 
support portion of the coplanar horizontally elongate legs 40a of frame 
members 14. In preferred embodiments, the thickness of the trench cover 38 
and the height of the vertical legs 4Ob of the frame members 14 are 
approximately equal. Thus, by aligning the uppermost portion of the rails 
14 with the upper surface of the trench forming composition poured about 
the form assembly, the upper surface of the trench cover 48 lies flush 
with the surrounding ground and the upper edges 51 of the trench. 
During placement of the form assembly in the preformed ditch, a plurality 
of batter boards 50 are preferably removably attached to the top surface 
12a of the removable form. As illustrated in FIG. 2, the batter boards 50 
typically extend laterally across the top surface 12a of the removable 
form. The batter boards 50 can be affixed to the ground by means such as 
wooden stakes or the like (not shown), so that the form assembly is held 
or suspended in a fixed relation within the ditch. Thus, the form assembly 
may be properly aligned by appropriately positioning the batter boards 50 
with respect to the ditch. 
In addition, in embodiments of the removable form body 12 which include a 
top surface 12a having first and second laterally spaced ear portions 18 
that are spaced to define a longitudinal central recess therebetween, an 
alignment member 28 is preferably placed into the central recess. The 
alignment member 28 is further preferably attached to the form assembly by 
a cord or wire 52. As discussed in the previously incorporated U.S. patent 
application Ser. No. 07/768,610 to Stegall, the cord or wire 52 also holds 
the frame members 14 in engagement with the slots 28 of the form body 12. 
The cord or wire 52 is preferably disposed within a slot 53 formed 
laterally across the form body 12. The lateral slot 53 extends downwardly 
from the top surface 12a of the form body 12 to a position below the 
longitudinal frame member engagement slots 38. 
In this embodiment, the batter boards 50 may be attached to the alignment 
member 28, by various means such as by a nail 56, so that alignment of the 
batter boards 50 with respect to the ditch may appropriately align the 
form assembly. Once the subslab 46 of trench forming composition has 
hardened about the lower portions 20 of the legs 42 of the frame means 14 
and anchored to the form assembly in the ditch, the alignment member 28 
and the batter boards 50 may be removed. The alignment member 28 and the 
attached batter boards 50 may be retained and reused on subsequent trench 
installations. 
The form body 12 may thereafter be removed from the trench as previously 
discussed. For example, in embodiments of the removable form which include 
a top surface 12a which include at least a first ear portion 18, the form 
body is preferably removed by severing at least a portion of the first ear 
portion 18 which integrally joins the truncated V-shaped wedge portion 22 
with the corresponding lateral portions 24. 
In preferred embodiments of the form body which include a top surface 12a 
having first and second ear portions 18, each of which are relatively 
narrow, i.e., have a lateral width of less than about 6 in., the removal 
of the truncated V-shaped wedge portion preferably includes the step of 
severing the portions of the first and second ear portions 18 which 
connect the V-shaped wedge portion 22 to the corresponding lateral portion 
as illustrated in FIG. 7. Severing of the ears can readily be accomplished 
by scraping the top of the form body with a shovel or the like, or with 
the scoop of a backhoe. Alternatively, a hand held automatic radial saw 
can be used to cut along the top of the ear or ears and into the preformed 
removal slot or slots. 
As previously discussed, the form body 14 may also include a second 
elongate form body portion 49 as illustrated in FIG. 11. The form assembly 
illustrated in FIG. 11 is installed in a similar fashion to that 
previously discussed such that the form assembly is placed and anchored in 
the predetermined location, such as a preformed ditch, with a subslab 46 
of trench forming composition. Hardenable trench forming composition is 
thereafter poured between the earthen walls of the ditch and the bottom 
and side surfaces 12c of the removable form body, including the second 
elongate form body portion 49. The form body 12, including the second 
elongate form body portion 49, is thereafter removed so that a trench and 
an adjacent structure, such as a curb, are simultaneously formed. In this 
fashion, a trench and an adjacent curb is efficiently formed and aligned. 
During the pouring and hardening of the trench forming composition about 
the bottom and side surfaces 12c of the removable form, considerable 
upwardly directed hydraulic force is exerted by the trench forming 
composition on the exterior surfaces of the removable form 14 due to the 
lower density of the form body 14. In addition to facilitating removal of 
the V-shaped wedge portion 22 from the removable form, the diverging first 
and second form removal slots 16 and the limited lateral distance 
therebetween on the bottom surface 12b of the form body limit the amount 
of upward force applied by the trench forming composition on the V-shaped 
wedge portion 22. In addition, the inward lateral hydraulic forces applied 
by the trench forming composition to the sides the form body increase the 
frictional engagement between the lateral or side portions of the form 
body and the interior wedge portion thereof. These forces also assist in 
retaining the V-shaped wedge portion 22 within the form body. Thus, the 
V-shaped wedge portion 22 is prevented from being separated from the 
corresponding lateral portions 24 of the form body and forced upward by 
the forces applied by the trench forming composition. 
The invention has been described in considerable detail with reference to 
preferred embodiments. However, many changes, variations, and 
modifications can be made without departing from the spirit and scope of 
the invention as described in the foregoing specification and defined in 
the appended claims.