<h1>Ruby - <s>139</s> <s>129</s> <s>126</s> 123</h1>

<pre><code>
(0..9).map{|i|(i*3...(i+1)*4).map{|j|puts"/#{'**'*j}\\".rjust(82+j,' ')}}
puts"%86s\n"%'|--------|'*11+'%86s'%'|________|'
</code></pre>
Ungolfed:
<pre><code>
# print fill patterns from the intervals
# [0..3, 3..7, 6..11, 9..15, 12..19, 15..23, 18..27, 21..31, 24..35, 27..39]
# centered on columns 81-82
(0..9).each { |i|
  (i*3...(i+1)*4).each { |j|    # x...y vs x..y-1 saves a char
    puts "/#{'**'*j}\\".rjust(82+j,' ')
  }
}
# print the stump
puts ("%86s\n" % '|--------|') * 11
puts '%86s' % '|________|'
</code></pre>