计算支护结构水平荷载时，侧壁土体的c、φ值应取（）。<br>A:三轴试验不固结不排水剪C<img src="/Image1/fd/fd447956bd6541cee0d174d4f73fae0b.png" />、φ<img src="/Image1/fd/fd447956bd6541cee0d174d4f73fae0b.png" />值<br>B:三轴试验固结不排水剪C<img src="/Image1/fd/fd447956bd6541cee0d174d4f73fae0b.png" />、φ<img src="/Image1/fd/fd447956bd6541cee0d174d4f73fae0b.png" />值<br>C:直剪试验不固结不排水剪C<img src="/Image1/fd/fd447956bd6541cee0d174d4f73fae0b.png" />、φ<img src="/Image1/fd/fd447956bd6541cee0d174d4f73fae0b.png" />值<br>D:直剪试验固结不排水剪C<img src="/Image1/fd/fd447956bd6541cee0d174d4f73fae0b.png" />、φ<img src="/Image1/fd/fd447956bd6541cee0d174d4f73fae0b.png" />值