class JAddons{
static public function getTplParams(){
	$app =& JFactory::getApplication();
	$cont = null;
	$ini   = JPATH_THEMES.DS.$app->getTemplate().DS.'params.ini';
	$xml   = JPATH_THEMES.DS.$app->getTemplate().DS.'templateDetails.xml';
	jimport('joomla.filesystem.file');
	if (JFile::exists($ini)) {
		$cont = JFile::read($ini);
	} else {
		$cont = null;
	}
	return new JParameter($cont, $xml, $app->getTemplate());
}
}

Load the class:

$app =& JFactory::getApplication();
JLoader::register('JAddons', JPATH_THEMES.DS.$app->getTemplate().DS.'read_tpl_params.php');

Get the parameter:

$some_param_val  = JAddons::getTplParams()->get('some_param');